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FI HTS ?
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blues90
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PostPosted: Fri May 20, 2022 4:02 pm    Post subject: Re: FI HTS ? Reply with quote

Back when I started this topic I ended up adjusting the MPS on my 73 type 3 auto trans . A month ago I noticed my idle was hunting again and the idle dropped 200 RPM . I checked everything and found I needed to give the MPS another 1/8 turn CCW. Back when I adjusted the MPS the first time I only needed 1/4 turn CCW

It seems like since the fuel prices went up it might be the fuel is not as good.

I didn't find anything else.
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PostPosted: Sat May 21, 2022 8:09 am    Post subject: Re: FI HTS ? Reply with quote

So you are adjusting this D MPS?
Tram has made a believer out of me adjusting/tuning my MPS with a screw driver & his o2 sniffer.

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PostPosted: Sat May 21, 2022 9:27 am    Post subject: Re: FI HTS ? Reply with quote

Mike Fisher wrote:
So you are adjusting this D MPS?
Tram has made a believer out of me adjusting/tuning my MPS with a screw driver & his o2 sniffer.

Image may have been reduced in size. Click image to view fullscreen.


yes I just turned the hex screw another 1/8th turn ccw.
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PostPosted: Sat May 21, 2022 4:56 pm    Post subject: Re: FI HTS ? Reply with quote

I have adjusted probably as many MPS as anyone and maybe more.

Yes....they are sensitive. If you are not practiced and do not have a "system" and test process for adjusting them....yes....you CAN and probably WILL chase your tail. So in that respect ....I fully agree that using an 02 sensor is probably THE way to go.

On the other hand.....1/8th turn is just about the largest increment you should ever use....without an 02 sensor....or a really good "stepped" testing process. With tight tuning of sensitive engines, even smaller increments are necessary.

But bear these things in mind with regard to what I mean about a system and process. This goes for using an 02 sensor as well.

1. If you are adjusting.....the MPS...... you only want to see what changes to fuel mixture baseline and running and driving.....YOUR ADJUSTMENTS....make.

If while you are adjusting the MPS, the TS-1 or TS-2 are changing resistance.....they are ALSO making adjustments. How do you know which adjusting did what.....see what I'm saying?

You need to warm the car up fully.....then lock out the TS-2 with a fixed resistor. Same for TS-

2. If you are adjusting in a garage with an approaching thunderstorm....the barometer is dropping. That is "adjusting" the MPS as well.

Lock out your sensors on a "nominal" fair weather day and drive a set circuit and adjust in fine increments. Also if you have PCV system with a valve...that can screw with you. Make sure its working properly. You can do AS WELL with this method as with an 02 meter. I have done both.

4. Anything that changes the way a D-jet engine runs....changes the vacuum signature. That changes the fuel mixture at the MPS.

Blues90....it's been what...2.5 years since your last post? How much has this car been driven? How are your plugs? Points? Vacuum lines?

And yes....really poor fuel can cause low enough performance that it can seem lean. Turning the load screw CCW...does richen it up. But if it was "hunting" it can be a myriad of things....fuel pressure....fuel volume....TS-1 because outside temp changed etc. Ray

Rule of thumb.....you NEVER adjust MPS unless all else is KNOWN to be correct.
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PostPosted: Sun May 22, 2022 10:54 am    Post subject: Re: FI HTS ? Reply with quote

raygreenwood wrote:
I have adjusted probably as many MPS as anyone and maybe more.

Yes....they are sensitive. If you are not practiced and do not have a "system" and test process for adjusting them....yes....you CAN and probably WILL chase your tail. So in that respect ....I fully agree that using an 02 sensor is probably THE way to go.

On the other hand.....1/8th turn is just about the largest increment you should ever use....without an 02 sensor....or a really good "stepped" testing process. With tight tuning of sensitive engines, even smaller increments are necessary.

But bear these things in mind with regard to what I mean about a system and process. This goes for using an 02 sensor as well.

1. If you are adjusting.....the MPS...... you only want to see what changes to fuel mixture baseline and running and driving.....YOUR ADJUSTMENTS....make.

If while you are adjusting the MPS, the TS-1 or TS-2 are changing resistance.....they are ALSO making adjustments. How do you know which adjusting did what.....see what I'm saying?

You need to warm the car up fully.....then lock out the TS-2 with a fixed resistor. Same for TS-

2. If you are adjusting in a garage with an approaching thunderstorm....the barometer is dropping. That is "adjusting" the MPS as well.

Lock out your sensors on a "nominal" fair weather day and drive a set circuit and adjust in fine increments. Also if you have PCV system with a valve...that can screw with you. Make sure its working properly. You can do AS WELL with this method as with an 02 meter. I have done both.

4. Anything that changes the way a D-jet engine runs....changes the vacuum signature. That changes the fuel mixture at the MPS.

Blues90....it's been what...2.5 years since your last post? How much has this car been driven? How are your plugs? Points? Vacuum lines?

And yes....really poor fuel can cause low enough performance that it can seem lean. Turning the load screw CCW...does richen it up. But if it was "hunting" it can be a myriad of things....fuel pressure....fuel volume....TS-1 because outside temp changed etc. Ray

Rule of thumb.....you NEVER adjust MPS unless all else is KNOWN to be correct.


Ray everything was still set . the points timing no vacuum leaks. On 5/20 2019 I replaced all the vacuum lines and fuel lines. Runner hoses and head gaskets. Since then I put 1300 miles on it. I even replaced the injector seals with good one's I got from Tram. After I did all of this work there was no change at all in the way it ran. This brought me to decide to adjust the MPS. Basically what I was doing to compensate for the hunting was unplug the IAD temp sensor. That made it run steady. I would describe it as hunting only in the respect that if I had it in park no load and brought the RPMs up to 1200 rpm then let off it would hunt then clear. basically it was more of an issue where if I brought the rpms up in park it didn't have a smooth transition from 1000 rpm to 2200 rpm , it would sort of hang and struggle like when you are trying to read the voltage output at a given rpm this made it impossible . What I did back then was adjust the MPS while the engine was hot and turn the hex screw CCW in 1/8th turns until it ran steady with the IAD temp sensor plugged in and each time while running I would unplug that temp sensor to compare how it ran with the MPS adjusted until there was no change . I ended up with a 1/16 turn more than an 1/8 turn CCW on the MPS adjustment .I tried turning it back the 1/16 turn CW and it was needed so I turned it the 1/16 turn CCW. I made marks on tape so I had the starting point and made 16 marks plus I filed a notch on the adjustment screw painted red so I could tell just how much I turned it. The PCV valve is still working. Even on a hot day above 90 degrees F the engine temp never goes above 180*. It did once a year ago when I was stuck on a 97* day because of a parade in bumper to bumper with all the other cars on black top . It still ran fine yet the oil light came on so I put it in neutral , had to be well over 110* due to the heat from other cars and sitting for over an hour in stop and go.

In the last few months since the gas prices went up it began this hunting again it also dropped 200 RPM . I checked the point gap and timing and it had not changed . When it's to lean it hunts . I checked the two temp sensors and they were still reading the same as they did in 2019. I figure since the gas pumps state at least 10% ethanol it's more than this. With the engine hot I decided to see what happened if I unplugged the IAD temp sensor and the hunting went away and the RPM was back to 1000 RPM in park rather than 800. I then decided to adjust the MPS 1/8 turn CCW richer and again compared this to the temp sensor unplugged and plugged in until there was no difference. Now it's back to where it was. I can only assume the fuel has changed enough to cause the hunting to return. I started it the next day fired right up then drove it and now it runs smoother and idle is steady. I didn't need to adjust the idle speed just adjusting the MPS brought it back to 1000 RPM in park. Seems the more ethanol the less gas is in the mix.

I didn't used fixed resisters on the temp sensors which I won't disagree with you on that idea.

By the way the points only have 1,100 miles on them and looked like new. I also got the good set from Napa with the vented contact and a point contact alignment tool off E bay . The set I have in there now are also sold by Napa they have the white nylon pivot and rubbing black all one section and the moving point contact is copper arm riveted to the Nylon they work fine next time I'll use the better Napa ones which have the two the actual spring and a copper conductor over the spring.

The other thing to note, when I rebuilt this engine in 97 I used flat top pistons and had the heads done , the machine shop slightly fly cut the heads . I got another dist just for spare parts I needed the vacuum advance can for my AH Dist . I installed it when I took the pertronix out. It had better pick up yet it began to ping after it got hot. Due to the flat top pistons the compression has to be higher and with the fuel we have I can't set it @ 5* BTDC . Right now I have the advance line plugged. Years ago with the stock dished pistons and better fuel it didn't ping. I need to find a timing setting below 5* BTDC .
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blues90
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PostPosted: Fri Jun 10, 2022 6:05 pm    Post subject: Re: FI HTS ? Reply with quote

Today it is hotter out side . drove it 12 mile round trip ran fine. got some gas before the prices go up again. I did notice since it was hotter today and the longer drive than usual and made a few stops never shut it down then. It still seemed a tad lean . Once I got home while it was still fully warmed up I gave the MPS another 1/16 turn CCW so it matched the IAD temp sensor unplugged. This amounts to a full 1/2 turn CCW total from the starting point. It started fine before yet I still felt at idle no load as I brought up the RPM it was not steady or say fluid. Basically it's 1/16 turn CCW more than the last time a month or so ago. I'd rather be slightly rich than lean. I do feel the issue if I drive till hot then shut down and wait a bit over 30 minutes the CTS the one on the head causes the idle to drop then after a bit it's fine again.

There are no vacuum leaks all the lines are less than 2 years old. I did this because I noticed when the auto trans is in neutral no load there is a 100 RPM hunt. Next chance I get I will check the valve lash again it's 600 miles before the 3,000 mile mark and this time I will do the adjustment like Russ suggested rather than using the distributor per reverse firing order . I did that years ago and got better results. I still hear them all clicking.
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PostPosted: Fri Jun 10, 2022 9:34 pm    Post subject: Re: FI HTS ? Reply with quote

Did you check the MPS and temp sensors for resistance? MPS for vacuum leaks?
half a turn is a LOT of change and I wouldn't think gas would make that much difference.
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PostPosted: Sat Jun 11, 2022 8:50 am    Post subject: Re: FI HTS ? Reply with quote

KTPhil wrote:
Did you check the MPS and temp sensors for resistance? MPS for vacuum leaks?
half a turn is a LOT of change and I wouldn't think gas would make that much difference.


No I didn't. It's been 2 years and 8 months since I last checked that. I don't drive much so in that time period less than 900 miles.

All I do know is back when I first adjusted the MPS I checked everything a few times just to get an idea where to go before I even attempted adjusting the MPS . At that time once I did adjust the MPS I adjusted it by 1/16 turns CCW . Since I don't have a way of checking the exhaust gas I adjusted the MPS so the engine ran the same as it did with the IAD temp sensor unplugged. That took six 1/16 turns CCW , two 1/16 turns less than 1/2 turn it is at now. It ran perfectly the rpm's rose in a fluid manner at the six 1/16 turn CCW . Then around a month ago I noticed when checking the charging system to see when the output was 14 VDC while bringing up the RPM slow I felt the same not fluid transition from 1000 RPM in park to 2300 RPM So I gave the MPS another 1/16 turn CCW and it was fine
What I did before adjusting the MPS again was disconnect the air intake temp sensor and the engine smoothed out and had a smooth transition then I adjusted the MPS.

I should check the resistance again and will plus see if the MPS has a vacuum leak. I never ran across an MPS even a very old one I still have that came on my car in 1985 that had a resistance that changed all were reading what the Bentley states they should . The original MPS does have a vacuum leak meaning I would have the engine running and pinched off the MPS vacuum line and it should stop running it didn't plus I could suck on the line and it would not hold vacuum. One the late 72 and 73 IAD the MPS vacuum line is at the top of the IAD so even the old MPS once I took it apart didn't have any oil inside.

Once I get a chance I will check the resistance of all three components. I realize 1/2 turn seems like a lot yet that MPS was never adjusted. I have no idea how much ethanol is in this gas now they say on the pump no less than 10% not what it really is. I do know when I changed all the vacuum lines and runner boots and head gaskets, fuel lines and injector seals and spark plugs in 2019 it ran the same, there was no change at all. So it was not a vacuum leak. I just did that work because I hadn't in a long time since 1997. I don't expect it to run perfect it's old , the only thing that did make a huge difference was adjusting the MPS in 2019. Parts like the temps sensors are difficult to find and if I do find new ones they cost a fortune. New ones might help. I do have another E system MPS that has never been used and I installed it and it ran the same as this MPS which I ended up having to adjust. Hell I'm 73 this work is not so easy.
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PostPosted: Sat Jun 11, 2022 5:29 pm    Post subject: Re: FI HTS ? Reply with quote

I checked the both temp sensors and the MPS.

MPS

7 & 15 = 97 ohm

8 & 10 = 354 ohm

I also checked to see if either coil was shorted to ground they were not.

Held vacuum didn't leak down.

The car was driven today and it's hot in my garage , I'm sure if I checked in the morning they would raise in resistance.

CH temp sensor 1440 ohm

Air intake temp sensor 157.2 ohm
also checked if either side was shorted to ground they were not.

I really didn't find any issues that stand out.

When I drove it today it had better pick up , I don't know what the actual emissions are yet I didn't see any black smoke or smell un burnt fuel yet that is not accurate just my observation.

To test I used two stock female connectors that used to go to the ring pickup plug wire # 1 which are 8 " long with factory crimps and a ring terminal at the other end and had my DVOM zeroed out , it was not just hoping the DVOM probes will make contact. I also made a male test connector from an old Fuel injector which I use to tell if any female connectors are loose and checked all of them on the MPS and Air intake temp sensor and they were all clean and tight. The CH temp sensor connector was also clean and tight.
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PostPosted: Sat Jun 11, 2022 7:56 pm    Post subject: Re: FI HTS ? Reply with quote

Sounds like things checked out okay. Part of me was hoping for the easy smoking gun, but no luck this time!

Tell us again which MPS and ECU you have on this car?

The photos earlier in the thread are strange...

It looks sort of like a C unit, into which someone has shoved/glued a hollow hex tool into. The main mixture is NOT this adjustment... you use a small/thin screwdriver through the hollow--and this is critical--do it while you hold the hex in place. In other words, adjust the inner screw independent of the hex.

I also do not see a full load stop/plug. So I am confused at what you have, and therefore how to adjust it.

I have been reading the sometimes contradictory information about adjusting the D MPS (used in '70 and '71). From what I can tell, there are three adjustments:
1) The innermost screw, which controls the main mixture, though it does not do very much at idle. Anyway, idle mixture is not important other than it should not stall.
2) The middle hex adjustment, which does not directly adjust mixture, but it controls the point at which the full load mixture adjustment (described next) takes effect. Critically, the inner screw has to move along WITH the middle hex, as a unit, when making this adjustment.
So you can see why you need both a hollow hex tool AND a narrow screwdriver, so you can choose to either move these together, or separately. Typically the inner screw moves with the middle hex, unless you hold the inner screw steady as you move the hex. But if it's been hacked or worn, it may nor may not!
3) The full load stop, which puts a limit on the ambient of high-load enrichment.

So as near as I can tell:

1) Start with the inner screw (while holding the outer hex from moving as you do so), and get a good A/F ratio at low part throttle/steady RPM state, maybe in the mid- to-high 13s at 2500 rpm.

2) Next, temporarily adjust the full load stop so it gets rich, but not too rich, at full throttle and at mid RPM... maybe 12.5 or so, maybe slightly lower, at 3000 RPM.

3) Now adjust the middle hex adjustment to determine if the full load enrichment is coming on soon enough, but not too soon. This is probably best done on a trial and error basis on the road, rather than with an AF meter.

4) Finally, make a full load stop adjustment again, based in mid-RPM full throttle, again shooting for about 12.5 or a bit lower at about 3000 RPM.

This is only good for the the'70/'71 C unit, which may not be what you have. I suspect you have a hacked E unit (despite the D cover!), but it really doesn't look like anything I've seen.

So please post your ECU and MPS part numbers, as well as the PNs of any other MPS units you have.


Last edited by KTPhil on Fri Jul 01, 2022 3:22 pm; edited 1 time in total
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PostPosted: Sat Jun 11, 2022 9:28 pm    Post subject: Re: FI HTS ? Reply with quote

Ok, I see from earlier in the thread you really have an "E" unit, despite the markings. To repeat:

Quote:
It has the stock ECU for a late E system which is a 048 not the 028.
The MPS is a 0 280 100 116 only has the Bosch #.
TS2 is a bosch ending in 003 also had one that was 012 both act the same way.
TS1 is the proper one 311 906 081A.
dist is the AH proper one for my car with an AT.
The TPS is the proper E system 5 pin and adjusted proper.


So my instructions for the "C" MPS do not apply to yours, and I started a new thread for that purpose.

Anyone got the intel on adjusting the "E" MPS? Is it similar to the original A/B units... just one adjustment screw/hex? Is the big black cap just an anti-tapering device, or does it have another purpose?


Last edited by KTPhil on Fri Jul 01, 2022 3:22 pm; edited 1 time in total
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PostPosted: Sat Jun 11, 2022 10:17 pm    Post subject: Re: FI HTS ? Reply with quote

This MPS has never been apart and the D is not what you are thinking. It does not have a full load stop. It had the black plastic cap which I removed then had to clear out the epoxy so I could turn the hex adjustment . The full load is in the 5 pin TVS not the MPS.

I was sent a new never used E system MPS by another member yet I don't have the number written down that I can find. I compared both and they are exactly the same. Only 72 and 73 type 3's had the later FI system and my 73 was sold in CA the 72 was not but was very similar the 73 in CA had the EGR both had the PCV system and same engine and trans. The MPS in the photo was on the 72 and looked new and it worked fine on my system until 2009 and I install new new E system map on my car when I got it a few years back hoping this would cure the problem yet it ran exactly the same as the one in the photo which was disappointing. My 73 Jim sent me the ECU number I should have and it matches and is the latest last update made. I tried the one from the 72 long ago and it worked the same so I have it as a spare yet it does not have the tag number. 72 and 73 also used the same TPS. I got the 72 as a parts car both had the same IAD except the 72 had the extra vacuum port for the dual can advance and retard 72 used other than that they are the same I just placed a rubber cap on that port since I don't need it. And both were auto trans . I used the 72 IAD because the 73 had the extra pipe on top behind the throttle plate a 1/2" pipe , rather than block it off once I removed the EGR valve which was rusted from exhaust I capped off the top of the right HE made a thick metal plate and it used a VW gasket just like the good metal exhaust gaskets only smaller like the beetle used for the preheat pipe for a single carb engine. Jim did basically the same on his 73 if he still has it only he made another plate to block the IAD port I mentioned earlier. I had the 72 so it was easier.

If you look in the Bentley where it shows the wiring for the 72 and 73 it explains the difference and I said if the 72 was sold in CA it to would have had the EGR . IN 1985 when I got my car I needed a rear bumper and the wiper arms mine were missing and there was no internet so I had no idea about parts just that I have many spares the 72 engine which is in the car now I rebuilt and I used the 72 trans because mine lost all forward gears so I used the best parts from both the 72 was just rebuilt so I had better clutches , I just used the best parts yet did use the valve body and governer off the 73 because they are matched. The only real difference between the 72 and 73 was the 73 had the three rail seats yet maybe a late 72 had those too, I am not sure because I don't know the built date of the 72 it did have the same late front brake calipers like the Porsche used many type three parts in 72 and 73 were used on Porsche. The fuel pressure regulator were also the same..

Basically what i'm saying is the MPS I used is the same thing as a E system nothing like D system as you know it. I think the D I have was a european part that's what Jim said . I don't know the history of the 72 so who knows where the MPS came from or who got it all I know is it's identical to the E system . I didn't want to screw with the E system MPS that was given to me since it was new I keep it as a spare just in case .
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PostPosted: Sun Jun 12, 2022 8:38 am    Post subject: Re: FI HTS ? Reply with quote

KTPhil wrote:
Ok, I see from earlier in the thread you really have an "E" unit, despite the markings. To repeat:

Quote:
It has the stock ECU for a late E system which is a 048 not the 028.
The MPS is a 0 280 100 116 only has the Bosch #.
TS2 is a bosch ending in 003 also had one that was 012 both act the same way.
TS1 is the proper one 311 906 081A.
dist is the AH proper one for my car with an AT.
The TPS is the proper E system 5 pin and adjusted proper.


So my instructions for the "D" MPS do not apply to yours, and I started a new thread for that purpose.

Anyone got the intel on adjusting the "E" MPS? Is it similar to the original A/B units... just one adjustment screw/hex? Is the big black cap just an anti-tapering device, or does it have another purpose?



I did find the MPS part numbers and ECU the complete numbers.

MPS in car now the photo I posted show the numbers.

Bosch 0 280 100 101 ( has black plastic cap over adjustment ) removed to adjust.
VW # 311 906 051 D

The one I got new looks and is identical to the D above.

Bosch 0 280 100 116 ( still has black cap)

The old original came on my car yet is screws together has SLOTTED SCREW adjustment.

Bosch 0 280 100 101
VW # 311 906 051 E ( has black cap over adjustment )

It looks like at some point was either rebuilt or who knows did work fine for years in fact I used the D unit in place of this old one long ago and it ran well it ran the same back then up until 2009. The D unit was on the 72 square I got as a parts car in 1985. I didn't know back in 1985 with no internet about parts the D unit looked brand new so I used it. Plus I have the ECU off the 72 it has no numbers and I used it in my 73 and it ran the same as the ECU below . I have it as a spare.

ECU
Bosch 0 280 000 048
VW# 311 906 021E

This is important . None of the early systems had this added ground system.

Note all the MPS units listed above and both ECU units I have all have the ground tab and the my 73 as well as the 72 had an added ground system there is a 1/4" male ground tab on the MPS units on the housing where one of the 4 rivets exist. The ECU units also have a 1/4" male ground welded to the metal case at the top . VW added this for some reason.

Also note the 72 and 73 cars had an EGR system so on both ECU's there is a welded on arm that a temp sensor screws in this temp sensor determines when the EGR valve can activate. This temp sensor looks identical to the one used to control the factory cold start valve on later models.

The Bentley calls it a thermo switch. In the Bentley Fuel system page 19 . Note it says Fig 10-3 73 and 72 cars sold in CA .
On page 18 you see 70 to 72 the thermo switch is # 18 only for the cold start .
To add on page 19 fuel system see the ground system added to the ECU and MPS compare to page 18 no added ground.

The sole reason I bring up the added ground is the D MPS I am using in my 73 now does have this ground tab .
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PostPosted: Sun Jun 12, 2022 8:54 am    Post subject: Re: FI HTS ? Reply with quote

KTPhil wrote:
Ok, I see from earlier in the thread you really have an "E" unit, despite the markings. To repeat:

Quote:
It has the stock ECU for a late E system which is a 048 not the 028.
The MPS is a 0 280 100 116 only has the Bosch #.
TS2 is a bosch ending in 003 also had one that was 012 both act the same way.
TS1 is the proper one 311 906 081A.
dist is the AH proper one for my car with an AT.
The TPS is the proper E system 5 pin and adjusted proper.


So my instructions for the "D" MPS do not apply to yours, and I started a new thread for that purpose.

Anyone got the intel on adjusting the "E" MPS? Is it similar to the original A/B units... just one adjustment screw/hex? Is the big black cap just an anti-tapering device, or does it have another purpose?


I have been told the black cap was part of maybe hiding the adjustment yet the actual adjustment is locked with epoxy. The "E" MPS only has one adjustment there is no full load diaphram and the rear housing is completely different . I have only seen one E MPS I have that had a hollow slotted screw adjustment still just one adjustment still the black cap. The other ones I have have an allen screw or hex . Both types the screw is hollow the screw being hollow is the only opening to sense atmosphere. The early MPS with full load have a different rear housing no need for the hollow adjustment screw.
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PostPosted: Sun Jun 12, 2022 6:26 pm    Post subject: Re: FI HTS ? Reply with quote

Drove the car again today. I noticed the pickup is better it runs stronger. My only concern is if it's possible it may be to rich. I don't see any black smoke out the exhaust , don't have exhaust probe . From all I've read being to lean is the killer . No place around here now uses the old sniffer it's all done on a dyno and most places have no info on these old cars so they can't check the exhaust. I don't know what it should read. It fires right up after shut down it's only the first start I need to prime the system via a toggle switch then it starts right up once the air is cleared out of the system. It has a new 2 port pump and it does have a check valve on the output side. It may be the fuel pressure regulator yet most places offer an after market one and for a lot of money. It does work as far as adjusting the fuel pressure and I can live with the primer switch. I don't smell fuel in the oil.
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PostPosted: Sun Jun 12, 2022 7:11 pm    Post subject: Re: FI HTS ? Reply with quote

I tried again to check the MPS for a vacuum leak I felt I didn't wait long enough . Well my old trusty mityvac plastic vacuum pump bit the dust so I went on Amazon and got a Actron all metal one. There were only a few left must have got the last one since now instead of a tool place Amazon offers it which they didn't before and it's $50 odd and I paid $30 for the same pump.

I liked the vacuum release better on the mityvac yet this one will do and at least it's not plastic. I had a metal mityvac in a case yet it was stolen. That one was nice. Amazon offers less expensive ones and they look the same as the Actron yet they have plastic handles that break so many bad reviews on the cheap ones which come with the brake bleeder stuff.

I just hope the MPS holds vacuum , I read wait 15 minutes I waited 5. If that's the case then I will need to use the new MPS and start over.
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PostPosted: Sun Jun 12, 2022 7:22 pm    Post subject: Re: FI HTS ? Reply with quote

KTPhil wrote:
Ok, I see from earlier in the thread you really have an "E" unit, despite the markings. To repeat:

Quote:
It has the stock ECU for a late E system which is a 048 not the 028.
The MPS is a 0 280 100 116 only has the Bosch #.
TS2 is a bosch ending in 003 also had one that was 012 both act the same way.
TS1 is the proper one 311 906 081A.
dist is the AH proper one for my car with an AT.
The TPS is the proper E system 5 pin and adjusted proper.


So my instructions for the "D" MPS do not apply to yours, and I started a new thread for that purpose.

Anyone got the intel on adjusting the "E" MPS? Is it similar to the original A/B units... just one adjustment screw/hex? Is the big black cap just an anti-tapering device, or does it have another purpose?


I wanted to thank you for posting your input on these systems and for staying with me . I also have a new CH temp sensor yet it's the one everyone sells now from euro parts and I tried to install it a few years back and found the threads are the same pitch yet the out threads are a lose fit in the head meaning you can rock it a lot so I didn't use it. Another cheap chinese repop. Didn't want to mess up the head threads. Years ago I bought a new German unit and as a fool placed it on the roof of my 73 drove off and it was gone. Now no one sells new ones.
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PostPosted: Tue Jun 14, 2022 5:31 pm    Post subject: Re: FI HTS ? Reply with quote

checked the HTS @ 75 degrees F it read 2215 ohm.
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PostPosted: Fri Jul 01, 2022 3:16 pm    Post subject: Re: FI HTS ? Reply with quote

The only thing that seems odd at this point is your MPS. It appears from this thread and others your wiring, hoses, and other components check out.

We know SOMEthing is wrong regarding the MPS, since it is marked "D", something not in any manuals I've seen. We are guessing it's equivalent to an "E" but that is conjecture.

Do you have access to an unmolested, non-leaking, electrically good "E" MPS?
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PostPosted: Fri Jul 01, 2022 3:51 pm    Post subject: Re: FI HTS ? Reply with quote

KTPhil wrote:
The only thing that seems odd at this point is your MPS. It appears from this thread and others your wiring, hoses, and other components check out.

We know SOMEthing is wrong regarding the MPS, since it is marked "D", something not in any manuals I've seen. We are guessing it's equivalent to an "E" but that is conjecture.

Do you have access to an unmolested, non-leaking, electrically good "E" MPS?


Yes I do , It's still on the car I just bolted this one on a spare hold on the same bracket.. I tried that one at first hoping it would fix the issue yet both acted the same way that's when I later changed all the lines and runner boots head gaskets everything and when done it made no difference at all.

I used the D MPS because I didn't want to screw up an untouched one.

How ever I do realize the numbers are not an E system yet the D MPS is identical in all ways I checked everything to compare them and there is no difference . These are what Ray calls a B type MPS with no enrichment and the hollow allen key adjustment. It worked on this car for years at least until 2009 yet in order for it to run proper i had to unplug TS1.

I really thought replacing every thing in 2019 would have cured it yet no dice.
I've been posting the results in the FPR post.
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