| Author |
Message |
Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
|
 Posted: Fri Mar 08, 2024 8:00 pm Post subject: Re: Flat spot on FI automatic |
 |
|
| t-royR wrote: |
Okay. figured out the multimeter.
That table of sensor resistance specs came from that FI pdf someone offered up earlier on. As I read that doc, it calls the head sensor, "#1", as can be seen by some pictures earlier on in the document. However, when they get to the chart, I believe they have the numbers mixed for the two sensors.
As I test the head sensor, I am getting close to the numbers the table shows for the case sensor. And, the numbers I"m getting on the case sensor match what the table shows for the head sensor. So, if I"m correct, the table is referring to sensor 1 as the case sensor and the sensor # 2 as the head sensor |
Correct. The chart shows them listed like the factory K manual.
2500 ohms at 20c-68f is your correct nominal value for the head sensor.
If both sensors are within 10% either way on the shown values they are in range- but here's a caveat: If they are BOTH 10% off in the same direction, that too can skew you rich or lean.
Sorry it took so long to get back here- work suddenly went mega brutal.
_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
|
| Back to top |
|
 |
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Sat Mar 09, 2024 7:41 am Post subject: Re: Flat spot on FI automatic |
|
|
No worries. That sensor is consistently outside of spec throughout the temperature range. Not even close to within the +- 10%. So, I assume that sensor is shot?
I'm going to run a second set of tests on the other sensor today to confirm numbers on it. First round shows it is close to within spec. With the room for error with my equipment, probably indication that sensor is okay. We'll find out.
I"m also going double check I have the hoses going to the right place from that air intake box. I have a pass through on the bottom of it, that I believe I have hooked up to the to the MPS on the one side, and the tranny pressure modulator on the other. But I also have another output on that box heading toward the passenger side, that I have hooked up to the pressure switch. I want to make sure I don't have those two hoses coming out toward passenger side, mixed up. Maybe the passthrough goes to the pressure switch, and the other output goes to the tranny. If you know, please let me know. I see there were several different air boxes over the years, with different input and output ports.
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Sat Mar 09, 2024 11:48 am Post subject: Re: Flat spot on FI automatic |
|
|
This pic shows the numbers I gathered from testing the sensors in a pot of water. The spec ranges are the numbers provided in the pdf, with the +- 10% figured in. The readings I list are the average of two tests on each sensor.
Please let me know what you make of these readings and what moves I should make.
I'll note that I have a later model airbox on the bench that has the air temp sensor. I removed it and found it to the be the same part as the sensor in my AAR location. I tested it at temps of 176 and greater, and found it too had low resistance readings (in the 30s and 40) as opposed to the spec of 80 Ohms. Either both these same sensors are bad and exhibit the same hight temp reading issues, or both are good, and I'm getting bad numbers. Seems odd they would be so exact in their Ohm measurements across these three high temp tests, if both were defective. But what do I know !
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Sun Mar 10, 2024 8:59 am Post subject: Re: Flat spot on FI automatic |
|
|
okay. Checked some part numbers. My car is a 1969.
The ECU has part number ending in B (which looks to be for 1968)
My MPS part number also ends in B, which is correct for this ECU
My TVS also matches with the ECU.
I'll check that the Pressure modulator in the tranny matches next, if that is something that is documented.
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
|
| Posted: Sun Mar 10, 2024 9:56 am Post subject: Re: Flat spot on FI automatic |
|
|
| t-royR wrote: |
This pic shows the numbers I gathered from testing the sensors in a pot of water. The spec ranges are the numbers provided in the pdf, with the +- 10% figured in. The readings I list are the average of two tests on each sensor.
Please let me know what you make of these readings and what moves I should make.
I'll note that I have a later model airbox on the bench that has the air temp sensor. I removed it and found it to the be the same part as the sensor in my AAR location. I tested it at temps of 176 and greater, and found it too had low resistance readings (in the 30s and 40) as opposed to the spec of 80 Ohms. Either both these same sensors are bad and exhibit the same hight temp reading issues, or both are good, and I'm getting bad numbers. Seems odd they would be so exact in their Ohm measurements across these three high temp tests, if both were defective. But what do I know !
|
I believe your book is still getting the flip flop of TS-1 and Ts-2 incorrect.
From your picture above.....by the numbers they are reading....the sensor you are reading in the column labled as "sensor 1 readings".....is the cylinder head temperature sensor and is called (after the nomenclature change)....TS-2.
The sensor you are reading in the right hand column listed as "sensor 2 readings"....is..., again after the mysterious nomenclature change in some books.....is actually the intake or. Crankcase temperature sensor called TS-1.
And....as Tram noted....a variance in TS-2 (the head temp sensor,) of +/- 10 is not a problem. It's pretty normal.
So the numbers you are reading at 68° F on the cylinder head temp sensor....meaning TS-2...meaning the one your picture is calling sensor 1.....the spec is listed 2250 -2750 ohms. Your reading is 2930 ohms. So your reading at 68°F is less than 10% off. The reading at 32°F....spec is 6490 ohms max and your reading is 7200 ohms. That is almost dead on 11%.
These readings are close enough....that I would say that the TS-2....the head temperature sensor....IS NOT your running rich problem. I can say this also because your 212° temperature...while your ohms are maybe a few percent too high for ideal....it's meaningless because that sensor does not run at full warmed up at 212°F. It runs closer to 300-ish and 8n almost all cases runs too low in resistance which is why many have had to run 200 ohm resistors in line.
So, take a pair of vise grip pliers. Clamp the TS-2 in the jaws lightly and put it in the oven at 300-ish for about 15 minutes. Then read the resistance.
No, it's not your TS-2. I will comment on the TS-1 later. I am out of time for a while.
What part # and how many wires on your TVS? Ray |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Sun Mar 10, 2024 10:23 am Post subject: Re: Flat spot on FI automatic |
|
|
For some clarity, the range I show already takes in to account the +- 10% allowed variance. Meaning, the book gave one number (with an allowance of +- 10%). So, I created the range you see, by subractng 10% from the book spec, and adding 10%. Thus, as I see it, my readings are not within the variance allowance. For example, the book calls for 2500 Ohms at 68 degrees. My reading is 2930. if you bump the spec up by 10%, comes to 2750 Ohms. Mine is well above that. Hope that makes sense. Maybe mine are close enough.
I'll try the oven test at 300 now.
Thanks!
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Sun Mar 10, 2024 10:28 am Post subject: Re: Flat spot on FI automatic |
|
|
That head sensor has a wire attached, with plastic insulation. Will that melt in a 300 oven?
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
|
| Posted: Sun Mar 10, 2024 1:42 pm Post subject: Re: Flat spot on FI automatic |
|
|
Ray- to correct what you said up there- I believe this engine is running LEAN, not rich. Every time I have unplugged a case/ intake sensor with the engine running on a sniffer, it has gone richer.
His car is an A/B with a 2 prong throttle sensor and secondary full throttle enrichment solenoid unter the right side intake runners.
_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
|
| Back to top |
|
|
Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
|
| Posted: Sun Mar 10, 2024 1:44 pm Post subject: Re: Flat spot on FI automatic |
|
|
| t-royR wrote: |
| That head sensor has a wire attached, with plastic insulation. Will that melt in a 300 oven? |
I don't think so. It's meant to withstand engine heat, after all. I would just position the wire so it's not in contact with any metal.
_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
|
| Posted: Sun Mar 10, 2024 3:17 pm Post subject: Re: Flat spot on FI automatic |
|
|
| Tram wrote: |
Ray- to correct what you said up there- I believe this engine is running LEAN, not rich. Every time I have unplugged a case/ intake sensor with the engine running on a sniffer, it has gone richer.
His car is an A/B with a 2 prong throttle sensor and secondary full throttle enrichment solenoid unter the right side intake runners. |
Thank you....I am busy with too many things right now and there are several D-jet issues going on between this forum and 411/412...I might be mixing up issues and thinking backwards 
Wait...I think I ASKED about whether he had the solenoid under the runners and he said no? Ok...found it back on page 1 and 2 and he DOES have the full load switch. Ok.
Yes...thinking backwards here. It runs when the MPS is disconnected from vacuum...which would cause the MPS to run it full rich.....so yes....normal situation with MPS connected is decidely too lean.
The problem I still see here is that the input from TS-2...does not constitute a MAJOR portion of the fuel enrichment calculation. Its like between 5 and 15% max depending on other conditions.
And even if as he said:
| Quote: |
| So, I created the range you see, by subractng 10% from the book spec, and adding 10%. Thus, as I see it, my readings are not within the variance allowance. For example, the book calls for 2500 Ohms at 68 degrees. My reading is 2930. if you bump the spec up by 10%, comes to 2750 |
I have driven and worked on D-jet all over the place for decades as have you....and even being 200+ ohms off up in the upper and midranges...just does not matter that much across most of the drivaebility range.
It may be a little difficult to start in some weather...and/or may run a little lumpy while warming up....but once its warmed up and the TS-2 has bottomed out then being 200 ohms off might be an issue but it wont be a LEAN issue if its too high.
The book says 80 ohms at 212*. His readings show 240 ohms in red. That is richer than 80 ohms.
The thing about TS-2....is that typical lowest readings of brand new TS-2 are around 65 ohms (lowest I have found) and about 70-75 ohms average on a fuklly warmed up car in warm weather. And, the thermistor inside of the TS-2 is not really capable of much lower resoonse than that and you see that because the REAL temperatures of the TS-2 in warm weather when screwed into the head are HIGHER than 212*. .
The 212* number is only used in that book because thats as hot as you can get water unless you are using a pressure cooker. Typically a well warmed up TS-2 after a highway drive can peak at 300* but is usually around 250* F.
Yes...agree his condition is lean....but I do not see that the TS-2 is doing it. Now.....as you note.....combined with the TS-1...under the right conditions....yes...it could be just lean enough. The TS-1 accounts for about another 5-10% of fuel mixture. Between them they "could" account for 25% of the total fuel mixture.
But, his TS-2 is actually a little higher than it should be at 212*. I wil lagree that his TS-1 is a bit farther off than is tolerable.
For testing of this issue...I have used a potentiometer (actual a 21 turn trimmer with a screw adjustment)...and just measured ambient air and looked at the ideal # on the chart and dialed in that resistance and plugged it into the TS-1 plug to see if that was causing the bad running.
Another thing that may be worthwhile to check...is to pop the top off of the TVS and tke a picture of it at throttle closed and mid throttle. While its simple...it CAN get out of whack when a previos owner has screwed with it. If the contact set is bent or its cutting off when it shoudl be staying on...it may cause an issue.
Its also worth testing the full load switch and checking its vacuum supply and wires.
Ray |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
|
| Posted: Sun Mar 10, 2024 3:38 pm Post subject: Re: Flat spot on FI automatic |
|
|
Oh...in case you are wondering about plugging a potentiometer into the TS-1 leads....this is what I made for testing and tuning It looks crude but works great.
Its a crappy piece of hobby circuit board with a 2500 ohm, 21 turn trimmer switch (about $4) with male pins soldered on one side to plug into the harness and a D-jet two pin plug on the other to plug into the TS-1 sensor.
So plugged in like that you can use it to add balalst inline to the TS-1 to see what it needs to run...or you can plug a loop wire into the female plug end and plug the male terminals into the harness and just dial in what you want to use the trimmer in place of the TS-1.
I put the whole thing insideof an old type 4 high beam relay enclosure.
Ray |
|
| Back to top |
|
|
Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
|
| Posted: Sun Mar 10, 2024 3:39 pm Post subject: Re: Flat spot on FI automatic |
|
|
Ray- Agree. Testing by pulling the connector on the case sender was merely a quick test to determine if lean was the issue. Second step is to test the temp sensors to either confirm or rule these out as the issue. Third step would be to remove the plugs and see if they are all burning the same. If not- find out why. If so, it's time to adjust MPS with the engine at full operating temp, ideally with a sniffer, once basic things like battery condition, valve adjust, point gap/ timing, and fuel pressure are verified as correct. Also- a big one- make sure the AAR has been cleaned/ lubed/ adjusted properly. Ideally you want this all the way closed at about 80 deg C. For testing purposes, though, removing the hose and plugging it after the engine warms up enough to idle without it will work. See if this alone kills the flat spot first, perhaps.
T-Roy, if we get to the MAP adjusting point I can lend a sniffer.
_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
|
| Posted: Sun Mar 10, 2024 4:12 pm Post subject: Re: Flat spot on FI automatic |
|
|
| Tram wrote: |
Ray- Agree. Testing by pulling the connector on the case sender was merely a quick test to determine if lean was the issue. Second step is to test the temp sensors to either confirm or rule these out as the issue. Third step would be to remove the plugs and see if they are all burning the same. If not- find out why. If so, it's time to adjust MPS with the engine at full operating temp, ideally with a sniffer, once basic things like battery condition, valve adjust, point gap/ timing, and fuel pressure are verified as correct. Also- a big one- make sure the AAR has been cleaned/ lubed/ adjusted properly. Ideally you want this all the way closed at about 80 deg C. For testing purposes, though, removing the hose and plugging it after the engine warms up enough to idle without it will work. See if this alone kills the flat spot first, perhaps.
T-Roy, if we get to the MAP adjusting point I can lend a sniffer. |
Yep....MPS is last thing. We may be getting there..... Ray |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Mon Mar 11, 2024 8:21 am Post subject: Re: Flat spot on FI automatic |
|
|
Can we agree I should put the temp sensors back in and move onto other testing? Or, should I consider replacement before moving on?
Thanks
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
Tram
Samba Socialist
Joined: May 02, 2003
Posts: 22729
Location: Still Feelin' the Bern- Once you've felt it you can't un- feel it.
|
| Posted: Mon Mar 11, 2024 12:07 pm Post subject: Re: Flat spot on FI automatic |
|
|
| t-royR wrote: |
For some clarity, the range I show already takes in to account the +- 10% allowed variance. Meaning, the book gave one number (with an allowance of +- 10%). So, I created the range you see, by subractng 10% from the book spec, and adding 10%. Thus, as I see it, my readings are not within the variance allowance. For example, the book calls for 2500 Ohms at 68 degrees. My reading is 2930. if you bump the spec up by 10%, comes to 2750 Ohms. Mine is well above that. Hope that makes sense. Maybe mine are close enough.
I'll try the oven test at 300 now.
Thanks! |
There's no "close enough", sadly. Out of range is out of range in my opinion.
I would replace any and all components that test out of range. What were the oven test results?
_________________
Немає виправдання для війни! Я з Україною.
| Bryan67 wrote: |
| Just my hands. And a little lube. No tools. |
To best contact me, please use the EMAIL function in my profile |
|
| Back to top |
|
|
raygreenwood
Samba Member
Joined: November 24, 2008
Posts: 21521
Location: Oklahoma City
|
| Posted: Mon Mar 11, 2024 2:16 pm Post subject: Re: Flat spot on FI automatic |
|
|
| Tram wrote: |
| t-royR wrote: |
For some clarity, the range I show already takes in to account the +- 10% allowed variance. Meaning, the book gave one number (with an allowance of +- 10%). So, I created the range you see, by subractng 10% from the book spec, and adding 10%. Thus, as I see it, my readings are not within the variance allowance. For example, the book calls for 2500 Ohms at 68 degrees. My reading is 2930. if you bump the spec up by 10%, comes to 2750 Ohms. Mine is well above that. Hope that makes sense. Maybe mine are close enough.
I'll try the oven test at 300 now.
Thanks! |
There's no "close enough", sadly. Out of range is out of range in my opinion.
I would replace any and all components that test out of range. What were the oven test results? |
Yep....a little out of range across one end like the high resistance end is not a big deal. A lot out of range on the low/hot end is an issue.
You need to check the oven test. Even 250° is fine.
Ray |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Mon Mar 11, 2024 3:00 pm Post subject: Re: Flat spot on FI automatic |
|
|
I did one test with the oven at 275. The initial Ohms reading I was able to get was 170 and then it quickly started climbing (that thing cools fast).
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Mon Mar 11, 2024 3:21 pm Post subject: Re: Flat spot on FI automatic |
|
|
I am still getting confused with the references made to these two sensors and which I am to be testing.
I just go done oven testing the sensor that screws into the head. And, at 275, it read around 170.
Is it the other sensor you suggest I test in the oven (the crank sensor that sits with the AAR)?
Thanks
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Mon Mar 11, 2024 3:32 pm Post subject: Re: Flat spot on FI automatic |
|
|
Added a new picture of my testing results table, and I removed reference to which number sensor it is, and used Head and Crank instead. Hope that hope
conversation going forward.
Thanks
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
t-royR
Samba Member
Joined: April 19, 2012
Posts: 464
Location: Minnesota
|
| Posted: Tue Mar 12, 2024 8:17 am Post subject: Re: Flat spot on FI automatic |
|
|
I'm all for new parts when called for.
On any purchase of these sensors, should I be shopping for NOS, or are there aftermarket that will be better or suffice? I see aftermarket head sensors that look like an easy fit, but not sure about what I"m seeing for after market crank sensors. I do see a few NOS crank sensors in Samba classified.
Thanks as always!
_________________
T-roy
75 Super
71 Super
71 Ghia coupe auto-stick
71 Ghia conv
69 Fasty
74 Ghia conv |
|
| Back to top |
|
|
|
