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  #46  
Old 06-27-2003, 11:52 AM
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Dave,

What year is your 16V? And what was the Bosch part number on your pot?

Did you remove the whole air flow meter to get to the pot?

Thanks.

Tinker

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  #47  
Old 06-27-2003, 12:47 PM
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THe part # question, and year model were answered on page one, post one..

the removal process was answered in another thread..

http://www.peachparts.com/shopforum/showthread.php?threadid=68427

If you have a part # ending in 15, it crosses over to the one ending in 35..
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  #48  
Old 06-27-2003, 01:00 PM
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tinker

It is a 86 16v, the pot i took out was3-430-591-017, since bosch doesn't make this part anymore I ended up using pot
3-437-224-035, I didn't take off the air flow, I just
took off the cold start lines and the fuel reg lines so i could see it better, and removed the distributer cap , so my hand could fit
behind intake, . it took about me about 30min
I know the 87 16v had a differnent airflow then the 86, I
bet it was pot 035 is the only differance
Dave
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  #49  
Old 06-27-2003, 02:13 PM
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Im sorry Tinker.. I didn't realize you were asking Dave specifically..

Please accept my appologies..

Jay
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  #50  
Old 06-27-2003, 07:52 PM
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Inadvertant additional research. Filled up again today, and mileage definitely seems to have improved by about 2-3 mpg, and is more in the range I expected from this car with my driving habits.

Steve
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  #51  
Old 06-28-2003, 09:28 PM
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***** mine still stalls on a cold start , worse now even gas pedel doesn't get her alive,once it warmed it has a soild idle with no starting problems??
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  #52  
Old 06-29-2003, 09:39 AM
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Dave, I'm worried that the new pot is apparently different from the old. The difference in total resistance is significant, as is the need to find a different setting for idle. The behavior you note could well be due to the differences.

It is reasonable that your idle is steadier - after all the instability is caused because the old pot had an erratic output - the new one is steady. To restore proper operation, though, you will likely have to get the correct pot. Look at it this way - if nothing else, you have diagnosed the idle problem to the airflow meter. If you have to shell out for the MB part and calibrate it, it should solve your problem. Perhaps someone on the board with an 8V or M103/4 will buy your new pot.

Steve
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  #53  
Old 06-29-2003, 11:45 AM
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Dave,

I think Steve is right, I bet the trim is incorrectly adjusted or the pot is slightly off alignment. I am amazed that you were able to remove it and install it in the exact same position as the old one given its location and the amount of injection pieces surrounding it. (For those not familiar with the 16V motor, they are a complete bear to work on)

I check the pot number on mine (87 16V) and it is the same number that Steve posted 3437.224.035. I ran the number you posted through a Bosch parts source and nothing came up.

Try to readjust as Steve stated and post your results.

Tinker
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  #54  
Old 06-29-2003, 12:51 PM
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the 16v in 87 got a new air flow meter, I have a used 87 one with the 035 pot stock on it , I haven't used it
I measured agian on DC V on 20,
off position
1 and 2 = .01
1 and 3= .00
2 and 3 .00

on position

1 and 2= .07
2 and 3 4.87
1 and 3= 4.85

EHA was -1.17 on position
and running it was -2.11 to - 5.87 at idle
and climbed to + 3.57 around 2500 rpm

do these numbers sound correct or way off??

I got it to start cold by turning the mixture screw a 1/2 turn clockwise ,I leaned it out by doing this ?? correct
Maybe I over my head now but I think I can firgure this out, I don't think it's rocket science, and I really don't like having others work on my 16v,
thanks
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  #55  
Old 06-29-2003, 02:58 PM
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Dave,

Are the EHA numbers you posted in ma or DC voltage? All the EHA readings should be in milliamps. The manual states that you should adjust to 0 ma at idle when warm. At a constant 2500 rpm you should not see it fluctuate by more than 10% from the idle reading.

Tinker
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  #56  
Old 07-07-2003, 08:41 AM
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No problem...

I replaced the pot without a problem.. Took the old one off, set the new one to match.. Put the new one on, and tested the voltage at .63 volts, which seems to be within specs. of +-.25volts..

The new pot seems to work perfectly. I can't honestly say that it solved any problems yet though.. I really couldn't find anything wrong with the one I removed.. Ay 147k miles, it seemed to be in fine shape..
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  #57  
Old 07-07-2003, 10:42 AM
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Jay, I'm guessing you still have the idle surging and hot-start problems, since those are what I found in a previous post. Note that in my case, there were other symptoms as well - surging and poor engine braking on decel, and occasional wild swings up to 1500-2200 rpm at idle. None of these have returned since I replaced the pot. In your case too, the car may have spent a greater percentage of its time on the road over the years in motion, instead of idling in rush-hour traffic - which wears that one spot excessively.

There is still a degree of roughness at idle - not silky smooth - that I interpret as injectors with a less-than-perfect spray pattern. This, since I have replaced all the intake hoses and cleaned the idle control valve (and valve job recently too). The actual speed variation is just barely noticeable on the tach, but perhaps this is the idle surge you notice too? I have the correct injector seals on order, and will try my hand at home-brew cleaning and diagnosis of the injectors when they arrive.

If you are getting bigger swings, and have not yet replaced the idle hoses, these harden and form poor contact at connections, allowing air to enter and bypass the airflow meter. When I replaced ours, I also did the rubber lower plenum of the airflow meter - all together pretty inexpensive from FastLane.

Steve
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  #58  
Old 07-07-2003, 11:04 AM
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Steve.. With the exception of an intemittent dead skip, which I know is not related, the engine idles so smooth that you wouldn't know it's running.. I replaced it hoping to fix a hot start problem mainly. I have a problem when the engine is warm.. It will start right up, run for a split second, and cut off.. It might do that several times before it will start, and run perfectly..

The old pot.. You would have to look very hard to find any wear at all on the carbon traces..
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92 Blown Buick Ultra Pimpmobile 220K and adding 1K per week

88 Wagoneer Slightly modified (Not for soccer moms)

04 Kia Sedona with every option... NICE
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  #59  
Old 08-28-2003, 01:06 PM
djjeant
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im curentlly having the same problem as you guys but the cars starts good, my new potentiometer should be here today, i have a 190e 2.3 16v wich are a pain in the a!! to work on but i removed all of the intake system all the way to the intake mainfole butterfly and removed that too and theres a something like the potentiometer on the butterfly i think mine isnt working correctly, i have rough idle and got the car to idle a lot less rough but bow the car lost power, i removed the potentiometer and the black band was very worn, if i didnt put it back on correctly could that be causing the loss of power, i also adjusted the mixture, maybe thats the problem right, anyway im waiting on the new part. also does the 16v have an altitude sensor, and is there a vaccum advance unit on the distibuitor cap like the one i see on the haynes manual for the 8v? i tried adjusting the timing on my 16v by moving the distribiutor cap and nothing happened????


thanx
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  #60  
Old 09-01-2003, 01:46 PM
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DJ,

The switch attached to the butterfly is a throttle position switch. It simply tells the ECU if the car is at wide open throttle or idle. There is an altitude module near the OVP/battery area. If you removed the potentiometer and did not reinstall it exactly as it was removed, then the signal it is sending to the ECU is probably off from the other sensors on the motor. It is not s simple remove and replace. It is difficult to get it perfectly calibrated if you did not mark a reference point before removal. The timing is controlled by the ECU after readings from a speed sensor on the crank pulley. The distributor has no effect on the timing.

Let us know if you having any luck with the new potentiometer.

Tinker

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