TheSamba.com :: View topic - FI Idling issues, fuel or Ignition or both?

Wed Mar 03, 2021 12:36 am

Still not getting this one idle properly.
Starts up but wants to stall, after a while and acouple of startups it runs but not smooth at all.
When giving throttle it chokes a bit but after a while it revs ok.

I have no vac.leaks.
Valvs adjusted.
Timing adjusted.
Fuel pr. 32. (have tested to run pressure in the range of 28-32)
New sp.plugs.

Acts weird.

https://www.youtube.com/watch?v=8aYsKLdJ9eI

The clip below,

Just started it (cold)
Revs up after appr. 15 sec.
Listen at appr. 2.00 mins when touching the throttle the first time since start.

https://www.youtube.com/watch?v=nnASTkmCzs8[/youtube]

Wed Mar 03, 2021 9:23 am

Ok.....we have been at this for a while :wink: .....if you want continued help....DO EXACTLY AND COMPLETELY what is suggested. Do not pick and choose....do not skip ANY steps or actions.

And please do not take this as me being pointy towards you. :D

The problem you are having.....I call slowly submarining idle.....or a version of it. From your videos....you are running excessively rich.

I am going to say this UP FRONT as its 100% obvious. As a root cause......your fuel mixture baseline setting is incorrect.

A second statement that is very relevent background information to kind of wrap the back or your mind around......D-jet......has an assymetrical injection timing pattern. Because the injectors fire in pairs 180° apart.....the actual timing point of when each injector opens and sprays....does not match up with an open intake valve.

I would have to degree wheel it for a type 3.....but crudely put....the enyine has one injector spraying its "fuel dosage" when the intake valve is open for the vast majority of the injection time.....another injector spraying with the intake valve open for only part of the injector spray period of time.....and two injectors that are spraying their fuel against closed or nearly closed valves.

At engine rpms above about 1500 or so.....this does not greatly matter because the time factor in milliseconds between when fuel droplets leave the injector pintle and when the next valve opening event happens....is just to quick.....for that fuel to make contact with the port walls and fall out of suspension into air....and fuel.....instead of fuel/air mixture.

But at idle rpm to just off idle.....this is happening too slowly. You have two intake ports that run wet. And.....once fuel droplets contact a solid surface and wet onto them.....it requires about 7-10X the heat and airflow.....to evaporate this fuel back off of the port walls and into the air stream.

This means that on these two "wet" ports.....you do not get a complete fuel charge or dosage into the cylinder. Those two cylinders INITIALLY run lean. Most of the fuel is left on the port walls. It is this way initially.....for a few dozen rpm cycles. But each cycle....more and more fuel is being left on the port walls.

Very quickly these two cylinders will be running rich from excessive fuel being scavenged off the port walls.....and its poorly atomized fuel. It does not burn well. It causes rough idle.

VERY IMPORTANT: THE FUEL MIXTURE IS VACUUM SIGNATURE CONTROLLED IN D-JET!

ANYTHING......ANYTHING....that causes a change in running...even very minute changes (either fuel mixture, ignition or load on the engine).....alters the vacuum signature. When the vacuum signature is altered.....the MPS reacts..... and changes your fuel mixture again.....which in just a few milliseconds.....changes the vacuum signature again.....which changes running....which alters your vacuum signature AGAIN....which the MPS reacts to...AGAIN. its a cascade effect.

To operate properly at idle...D-jet is designed to run almost excessively lean.....to prevent EXCESSIVE build up of unscavenged fuel in the ports.

So again......you are running excessively rich......or lean.... :wink:

How could it be either you ask?
Same problem. If you are excessively lean.....it causes unwanted changes to combustion. That makes unwanted changes to vacuum signature. That causes over reaction by the MPS.

So....why cant we say just at a glance that its either rich or lean?

A quick observation:

Turning your idle screw is making no difference.
This can happen if you are excessively lean.....because you already have so much air in the mixture that adding more....has no fuel paired with it to make any change to rpm.

This can happen is you are excessively...grossly....too rich....because you have so much fuel in the mixture.....that the idle screw cannot possibly add enough air to make enough difference to change the rpm.

So.......

First.....why are you at 32 psi fuel pressure?
That is a whopping 14.28% EXTRA fuel mixture.

The statememt "tested down to 28 psi".....but you are for some reason using 32 psi.....should be ringing alarm bells. Lets explore WHY this should not be done.

1. So....what is scale range of the gauge you are using? Depending on the gauge "class"....this is hugely relevent. The gauges have accuracy issues typically broken into first 25%, middle 50% and upper 25%.
If for instance you are using a 120 psi gauge.....the first 30 psi will be the most accurate, the middle 60 psi from 30 to 90 will be the next most accurate and the upper 30 psi the least accurate. Ideally you should have a gauge with a top end of about 40 psi for testing D-jet....but that's very hard to find.

2. What "CLASS" of gauge are you using? Typically water pressure....and cheap pressure gauges in general....bought at hardware stores, parts stores and home stores.....if they have any classification or certification at all....are class "D" gauges....or Class C at best.

A class D gauge is only accurate to +/- 5% over the entire gauge range. This means that if you "think" you are at 32 psi.......you could actually be anywhere from 33.6 psi to 30.4 psi. Thats a big spread.
And....factually....if you do not see a classification listing, stamping or marking.....these are typically unclassified. Uncertified.....meeting no real standard. Most basic unclassified gauges I have tested are about +/- 3.0 psi off.

So you could be anywhere from 29 psi to 35 psi. A 6 psi spread represents a possible 21.4% delta in fuel mixture.

So if you do not have a very good fuel gauge.... at least a class A with a maximum 60 psi gauge face or a class 1A is better.....then you have no idea within about +/- 3 psi....ofcshat your fuel pressure REALLY is......and yet you are running 4 psi over specification. :wink:

https://www.instrumart.com/pages/539/pressure-gauge-accuracy-grades

3. Why is your particular fuel pressure relevent?

A. The D-jet injectors are low impedance. They are this way partly because they have low spring tension. They have a functional pressure limit. When they reach 35 psi or higher.....the angle ground on the pintle causes the spray pattern to revert from a CONE of droplets....to a STREAM of non atomized fuel.

You already have an atomization issue at low rpm due to the injection timing issue listed above. Excessive fuel pressure makes it worse. It runs worse. The vacuum signature gets worse....the MPS reacts worse.....its a cycle.

B. When these injectors start cycling faster.....starting around 35 psi and higher fuel pressure makes it to where the low tension spring inside....cannot properly seat and close the injector on each cycle. They become wildly inaccurate and you run horribly rich at cruising rpms.

C. The D-jet system has no idea what your fuel pressure is. It has no sensor and no downstream diagnostics (no 02 sensor).
It is set up based around ONE FUEL PRESSURE SPEC. It runs its fuel dosage as "fuel pressure X pulse time". In order to make accurate fuel dosage decisions.....it ASSUMES the fuel pressure is correct and stable.

The factory chose 28 psi with these injectors.....because its high enough to create good atomization.....and high enough that it can lose a percentage after shut down and still maintain prevention of vapor lock.....and yet still low enough that its not approaching the injector spring and pintle limitation.....and still within the limits of the average decent gauge.

Yes.....you will see many people stating they run their D-jet at about 2 psi higher than stock. Even running 2 psi with the average class C gauge variance....they are probably getting lucky enough to stay below the 35 psi problem limit.

But the stupid part is this......if you have to run elevated fuel pressure to get your engine to run better or properly......what is this REALLY telling you?

Its telling you that your baseline fuel mixture adjustment ......AT THE MPS.....is INCORRECT.

Adjust your fuel mixture. Adjust your MPS.

Ray

Wed Mar 03, 2021 10:33 am

Have you checked your MPS for leaks?

Wed Mar 03, 2021 11:20 am

@Ray, jupp it has been going on for a while :)

NOTE! I don`t find it or anyones comments/suggestions pointy at all. :)
I`m putting my head out there asking you guys for input. I`m taking it all in.
Or trying at least ;)

1. I wanted to see if it ran better or worse-trying out different preassures.

2.Do not know what class the gauge is. Tried to find it out.
I`m running on a liquid filled Summit Racing gauge. "SUM 800-160".
https://www.summitracing.com/int/parts/sum-800160

I`ll check the gauge vs my kompressor to see if its calibrated. But if it`s off, it`s off regardless.

//Ken

[/u][/b]

Wed Mar 03, 2021 11:21 am

KTPhil wrote: Have you checked your MPS for leaks?

@KTPhil, I have. Tested it`s preassure a couple of months ago.

MPS resistance, pin 15 & 7, 91 ohms. Pin 10 & 8, 349 ohms
Held vacuum (10 in-Hg)

Wed Mar 03, 2021 2:47 pm

Have you checked ignition advance and stability with your timing light? If your distributor is wearing out, the unsteady firing can make it run roughly, and also disturb your idle injection timing.

Wed Mar 03, 2021 11:15 pm

Sorry I could not get a gauge part number to you earlier in your PM....these guys in Newark are KILLING me! I'm waiting on a new computer screen that got lost in the mail foir my laptop.....so I am on my windows 7 laptop.....a dinosaur....but saving my ass....and no access to my files. It just so happens that my list of links to articles and threads...I have not duplicated in dropbox.... :roll: ...how *fing stupid of me!
:lol:

Here is a short list just from McMaster carr. Look at the detail on these part numbers and you can actually buy them elsewhere...or at Grainger.

I have a list.....because....whats your budget for a gauge?

The ideal gauge for REALLY dialing in and tuning D-jet (or any EFI)...is a class 1A gauge or better. The ONLY difference between an EXPENSIVE class 1A and an average class 1A is that it has graduations of 0.5 psi instead of 1.0 psi. The class 1 gauges.....all have 1.0 psi grads....and are usually not full scale accuracy...but middle of scale.

But still....a lot of times a class 1 and class 1A...are usually accurate across 100% of the scale.

This means that your error "spread" on a 1A ...is only 1.0 psi...very nice. I have one.

But a class 1 is just fine. It reads in 1.0 psi increments......but is still accurate to 1% of full scale...so when you "see" the needle moving at 1/2 psi increments....you can trust it.

There are plenty of class B gauges as well...but not on my list. Class B gauges are only 1% better across the board than C gauges....and not much cheaper than A or 1A gauges...so why bother?

There are many places to buy gauges at somewhat better prices....now that you know what you are looking for.
But McMaster carr....is also worth the slightly extra money for always being in stock and exactly what is advertised and great customer service and easy purchase.

Gauges from McMaster Carr:

Note that this first one is the most expensive on the list but is the only one with 0.5 psi graduations. There are others available....but similar or higher pricing.

Class 1A with 0.5 psi graduations…very nice gauge…but pricey.

Part #: 4240K7 4” diameter / bottom fitting-1/4” NPT/ 0.5 psi graduations/ +/- 1% full scale good to -40 to 200°F- $86.28

Vibration resistant class A/ Glycerin filled gauges:

These are a bargain for an accurate gauge if your budget is low...

Part #: 3845K1 / 0-60 psi/ ABS plastic case/ 1 psi graduations/ glycerin filled/ bottom or back connection (accurate to +/-1% of the middle of the scale range) $21.31 for bottom connection $22.31 for back connection

Brass case with brass connection: class 1A/ glycerin filled

Very nice gauges

Part #: 4090K15 / 0-60 psi/ 1 psi graduations/ glycerin filled/ available bottom or back connection/ 2.5” face diameter/ accurate to 1% full scale/ $62.04 each

305 stainless steel case gauge:

Very good value and price

grade 1A/ Glycerin filled/ 1% full scale accuracy
Part #: 4053K15/ 2.5” face/ 0-60 psi/ 1 psi grads/ bottom connection/ $32.62

Part #: 4052K16/ 4” face/ 0-60 psi/ 1 psi grads/ bottom connection/ $55.34

High clarity dial/ nylon case with brass construction/ class 1A

The nylon case means something. Most solvents and fuels will not touch it....and its tough as nails.

Part #: 3708K21/ 0-60 psi/ 1 psi grads/ glycerin filled/bottom connection/ $42.60

High clarity reading dial/ nylon case with brass construction/ Grade 1A with internal anti corrosion seal

Part #: 3715K21/ 0-60 psi/ 1 psi grads/ glycerin filled/bottom connection/ $69.00

I have other lists with more choices ...I think...but cannot access them for a day or so.

So...what the gauge will allow you to do is:

A. know exactly what your fuel pressure is

B. Know EXACTLY how stable it is.

This will tell you a lot about your fuel pump...your regulator...and your injection timing :wink: ...that last one is a longer discussion.

BUT simply put...your injection timing is slaved to the distributor. If your ignition timing gets too far out...or too different....and this can happen if you are using an ignition points replacement module .....it changes the injection trigger point timing in relation to the camshaft valve opening point....which will throw off your injection timing....which changes the combustion...which changes vacuum...which changes fuel. All of this adds up.... :wink:

This screws with the vacuum signature....and fuel enrichment.

The REAL root cause I can tell you.....is that....IF...you have no other issues...vacuum leaks....wiring issues...sensor issues...adjustment issues...and if you can verify that your fuel pressure is stable and accurate......your MPS needs to be adjusted.

So yes...you need a good fuel pressure gauge. Ray

Thu Mar 04, 2021 6:14 am

Hey, no worries. Ain`t going anywere :)

Ok, I`ll get the right tools for testing the pressure ASAP.
IF i would trust the gauge it`s at 28 now.

Checked the timing again.
TDC, 0 degrees.
Rotor pointing at the notch in the distributor.
Adjusted the distributor from 0 gap in the ign.point to slightly open and the testing light turned on.

Started it up and it ran like this:

https://www.youtube.com/watch?v=CHeaMmwWgy0

Thu Mar 04, 2021 8:10 am

digg75 wrote: Hey, no worries. Ain`t going anywere :)

Ok, I`ll get the right tools for testing the pressure ASAP.
IF i would trust the gauge it`s at 28 now.

Checked the timing again.
TDC, 0 degrees.
Rotor pointing at the notch in the distributor.
Adjusted the distributor from 0 gap in the ign.point to slightly open and the testing light turned on.

Started it up and it ran like this:

https://www.youtube.com/watch?v=CHeaMmwWgy0

Oh...wait....I keep forgetting you are in Sweden.

Getting an accurate cheap gauge should not be a problem. As you can see from the list I posted.....its about just searching for the classification and looking at industrial supply houses even where you are.

But.....you migjt need a list of gauge qualifications for DIN measurements. I will look for it.

Wika out of Poland makes very good gauges.

The other important item......are you setting your ignition timing with a simple test light while the engine is off....or are you using an electronic timing strobe light while it is running?

With D-jet....gour timing should only be set via the electronic strobe light. Ray

Fri Mar 05, 2021 5:16 am

He he, jupp Sweden it is.

I`m looking for another gauge.
All the gauges for cars ar either cheep och superexpensive and not many at max. 60 psi.

Setting timing rough with a light.
Have strobe but not vid any adjustments.

Looked in the manual. I`m supposed to be at 0 degrees.
Then there are the other 3 markings to the right. to the right of thoose there is av white marking aswell. Guess someone marked it before by some reason.

I connected a rpm gauge in order to se what rpms Im at and to se how much it drops and when in time, when running at Idle.
But, that gauge shows about 1800 rpm though it runs at a max of 750-800.
Would that indicate something`s wrong with my distr.?

//Ken

Fri Mar 05, 2021 5:22 am

Fri Mar 05, 2021 8:51 am

The timing marks are as follows- Big mark all the way to the left= 0*

Smaller marks L to right are=5, 7.5, 10* BTDC.

I bet the white paint mark is around 30* BTDC

Fri Mar 05, 2021 9:09 am

Ok....a couple of items:

1. While a 60 psi gauge would be ideal .....especially if its NOT a super accurate gauge. Because the lower accuracy gauges typically have the best accuracy in the middle 1/3 of the scale.....50- 60 psi would be the best gauge range to have when you are stuck with a class C gauge from a hardware or home improvement store (like a water pressure gauge).

Those are "good enough" when you are just checkimg function or regulator bleed down time etc. But....not good enough when you are chasing "fine tuning".

What I am saying is that do not get stuck on looking for an exactly 60 psi gauge.....IF.....you can find a MORE ACCURATE "class" of gauge.

If you are looking for a class A or 1A.....where the gauge is accurate to the full scale range.....then even a 100 or 120 psi gauge range is just fine.

However, what you want to avoid is any gauge that has marks or graduations that are greater than 1 psi. Ideally.....when you can find them (and they are usually more expensive)....gauges with 0.5 psi graduation marks are absolutely better. But 1.0 psi marks are just fine.

2. In your picture, the left hand mark is "0". The three marks to the right are......I am pretty sure....are ..7.5 BTDC, 10 BTDC and 12.5 BTDC.

The white mark....I have no idea.....but I am betting that is what the previous owner found that the timing moved up to when he disconnected the vacuum retard without then reducing the idle speed back to normal.

In the books.....all timing is performed with the vacuum advance hoses removed. The order of events is:

To set your idle speed with the hoses on.
Then make absolutely sure that the throttle flap is all the way closed.
Then remove both hoses if you have vacuum advance and retard.
When you remove the retard hose....the idle will increase.
You must re-adjust idle back down ro normal.
Then set the timing.
Then re-attach the hoses.
The idle will DECREASE.
And then finally readjust idle back up to normal AGAIN.

This method is a problem on older cars.....because.....with age, the springs in the mechanical advance unit can get weak....and/or the weights and plates do not move as smoothly as they should. So setting the timing can be overly sensitive to small rpm changes.
If the springs are weak.....the mechanical advance can start kicking in at too low of an rpm. If the mechanism is sticky.....mechanical kicks in late.

One thing I have found with virtually all D-jet VW engines.....is that due to changes, wear and modern fuel....virtually all of them run and idle better with slightly MORE than the stock idle timing setting.

I would bet you will find that yours will operate and set better at 7.5 to 10.0 BTDC like the later models.

And.....you MUST use a timing strobe and not a signal light. The difference in these two methods is several degrees of accuracy......and.....the timing strobe has another very important function. It allows you to see if the timing is STABLE. This diagnoses both leaks in the throttle plate and issues with the mechanical advance sysytem.

3. The issue with your rpm gauge. Typically the electrobic tachometers have a setting for 4, 6 or 8 cylinders. When you are timing a 4 cylinder.....and its set on 8 cylinders.....your reading will be double (I think that is thr ight direction in my head).....and that would be close.....as you "should" be right around 900?

Ray

Fri Mar 05, 2021 3:08 pm

The white paint line is probably for total advance reference (with a timing light).

Sat Mar 06, 2021 3:43 am

Regarding gauges.
Found som WIKA gauges, wolud any of theese be good enough?

https://www.automation24.se/sv/compare

WIKA Accuracy class 1,6 = 1,60%

1 bar 0,02
1,6 bar 0,03
2,5 bar 0,04
4 bar 0,06
6 bar 0,1

■ For measuring points with high dynamic pressure loads
and vibrations
■ For gaseous and liquid media that are not highly viscous

Sat Mar 06, 2021 9:57 am

digg75 wrote: Regarding gauges.
Found som WIKA gauges, wolud any of theese be good enough?

https://www.automation24.se/sv/compare

WIKA Accuracy class 1,6 = 1,60%

1 bar 0,02
1,6 bar 0,03
2,5 bar 0,04
4 bar 0,06
6 bar 0,1

■ For measuring points with high dynamic pressure loads
and vibrations
■ For gaseous and liquid media that are not highly viscous

From Wika's PDF chart.....I would say you are looking for accuracy class 1. The accuracy classes of 1.6, 2.5 and 4.....pertain pretty much to 40-50mm diameter gauges. Not that its that important to have a larger diameter gauge.....but the point that they are making is that if you want a gauge to be more accurate.....the dial graduation printing and spacing also need to be as accurate as the gauge mechanism.....so a larger gauge diameter is required to get that accuracy.

The 1.6 class (which means +/- 1.6% of the gauge permissable span) is about the equivalent of a very good class C or a decent/average class B gauge.

For what Wika makes (and other EN or DIN gauge manufacturers).....the 4.0 bar gauge would be closest to what you really need.....4.0 bar being 58 psi. The next standard gauge down from that is 2.5 bar.....36 psi....not enough.....and the next one up is 6 bar....more than you need...but....
If you can find a 6 bar gauge in EN/DiN class of 1 or 0.6.....that would be just fine too.

But.....in the EN class gauges like Wika makes......1.6 is BEST class they offer in 40-50mm gauge sizes.

The first size available in class 1 is 63mm. They make class 1 in 63mm, 80mm, 100mm, 160mm and 250mm.

Likewise....there are no gauges available in class 0.6 less than 160mm and 250mm.

So I would say the minimum you are looking for.....is a 63mm, 4 bar, class 1 gauge from Wika.

Ray

Sun Mar 07, 2021 6:49 am

Ok.

I just got hold of a guy that I can rent a fuelpressure testing device from for 15 usd/day. That sholud do it. As long as it`s of fairly good quality.

However, I just have tor get i runnin "better" on idle. Having problem keeping it on idle not reving it too much in order to set the timing..

Sun Mar 07, 2021 8:15 am

digg75 wrote: Ok.

I just got hold of a guy that I can rent a fuelpressure testing device from for 15 usd/day. That sholud do it. As long as it`s of fairly good quality.

However, I just have tor get i runnin "better" on idle. Having problem keeping it on idle not reving it too much in order to set the timing..

Really....before you spend that kind of money on renting....check around.

Aside from the gauge cost. ...fittings.....less than $3 USD. Hose ....maybe $8 usd depending on price per foot and you need about 2 feet. Two hose clamps.

You might spend $30-ish or less on a useful gauge. Yes.....you can get away with a 50mm class 1.6 gauge of 4 bar range.

The point....is not to spend excessive money on a gauge.....but to know its accurate...and to what level its accurate.

Two days of renting a gauge of unknown quality and condition and you have paid for usually a better gauge than you can rent . And that second part is almost the biggest problem.

Once I bought a decent gauge.....and helped a few people out over the years who were having problems (back when I was working on CIS injection a lot).....I found NOT ONE rental gauge even from the best parts stores....that was either better than a C class in accuracy.....but even worse....the few gauges that were high tolerance gauges that friends of mine rented from European sports car,specialty shops.....were way off.

The problem with gauges that are rented out....is that if they are dropped or allowed to get hot or run for a while under the hood (high vibration and heat)......then they get way out of calibration. No one at the parts stores was bothering to regularly send the gauges out for recalibration.

And.....you really need to have a gauge of your own to properly work on D-jet. If all you can find or afford is a class C gauge.....that can be ok.....but it has to be a narrow range gauge like 40 psi where the target pressure you are looking for is right there in the exact most accurate range. Thats a hard gauge to find.

Class B gauges have the same hard to find issue.

The gist is that pressure....with D-jet....when you are chasing FINE tuning issues......is not just a set it and forget it. It is a diagnostic tool.
The gauge needle will rarely be exactly steady. How it moves at idle and when you rev and at upper rpm ranges with D-jet.....will tell you condition of fuel prump, regulator, voltagd to system, injection and ignition riming combined and overall adjustment of MPS. All of these items affect fuel mixture.

All of that being said......let me suggest this course of action.

You just noted that you cannt keep it running at idle. That's an important key we did not know earlier.

If you cannot keep it running at idle long enough to use a timing strobe.....then this means that your timimg will not be correct because you are using a test light. It will probably be as much as 5° off.

Thats a lot. It also affects your injection timing at the same time. Both of those alone.....seriously affect running.....and will cause the idle cascade and stalling issue I noted a few posts back.

And....you have been running fuel pressure excessively high in order to get better running.

All of those issues.....tell me that your fuel mixture is off by a large amount.

So.....lets start at a crude baseline level. You are not at the "fine tuning" level yet.

In most cases.....we see this a lot with L-jet injection......everyone is just told to go to the home store and get a basic water pressure gauge and FOR THE MOMENT....make sure that your system is getting enough pressure but not grossly too much or too little. Get it in the general range enough to accomplish steady running for further tuning.

While D-jet is a little more sensitive than L-jet......that method stands to be useful in your case for the moment.

What we need to see....is a picture of your MPS.....so we know which type and system.....and list the part #.....and also a picture of the end of the MPS opposite where the vaccum hose connects to it.

If you can rent a basic gauge.....set your pressure to no more than 29 psi......this way if its 2 psi too high or low due to gauge type and accuracy......its close enough for the moment.

The next stage will be to make a quick tweak to the MPS to get the system idling well enough to tune. Ray

Mon Mar 08, 2021 12:38 am

I`ve got it! :)

I`m getting a good gauge with the right class grading.

This is where I`m at after some "tinkering" this weekend.

1. Looked at valve gap. Set on 0,10 mm.
2. Timing at 0 degrees.
3. Distributor and rotor at 7 o`clock.
4. "breaker? point gap set at 0,4 mm.
5. Sparkplugs, cleaned and gap set at 0,7 mm.
6. F pressure, 28 (with my gauge).

Initially I had no idling at all. Finally I got it running.
Crappy, but still running.
I looked at the timing with strope and it showed appr 7-10 degrees.
I tried to hear if it reacted when pulling/feeling at all connections, injectors/distributor/ground at case... no difference.

Pulled the plug (is`t plugged) at the AAR, had a tiny rev up after appr. 5 sec, but "fell back" at low rpm again.
The AAR is sucking.

Airscrew setting does not make any changes. If screwing it down tight it stalla ofcourse but I can pull it all the way out without doing any difference to RPM..

But... when pulling the Intake Air Temperature Sensor, the RPM changes and I get a more stable RPM.

Shown in the video below (0,50 sec. in).

https://youtu.be/z4DhIsPxwRM

My MPS, 311 096 051C.

https://www.thesamba.com/vw/gallery/pix/2001752.jpg
https://www.thesamba.com/vw/gallery/pix/2001753.jpg

//Ken

Mon Mar 15, 2021 7:40 am

So, I got a tip to look at the TS2 sensor and its resistance.
`
Had a broken one before and installed it new last summer. I`ve checke the resistance on it and it`s good.

However, I was told that it came with extra an added resistance on 914:ns.
I added a "5w 300 ohm" resistance ant tried to start it up.

First clip, idel without extra resistance.
https://www.youtube.com/watch?v=z4DhIsPxwRM

Second clip with....!!!
https://www.youtube.com/watch?v=MrQUqkNnt1Q

When running I tried to remowe the plug in the AAR hose. Reacted with bad idling. Plugged it again.

Then unplugging the TS1, runs ok with or without it.
It even reacts to airscrew adjustments now.