[Tomspassat]

my 1996 passat stumbles a little at low rpm. it seems to be about 1700 rpm, it seems to jerk a little, the car runs OK otherwise.

 

[chittychittybangbang]

First see if there are any codes. It could be a few things...but it could also be nothing. For some reason, some mk3 diesels have a low rpm stumble that is normal.

 

[5point]

i heard that this computer gets confused if you balance the rpm, load, speed, etc., just right. it gives little more, little less gas, so if it goes away with a little more throttle, and everything is okay, that might be the problem

mine had this and then it just went away or I drove different and don't notice it

 

[diesel guy]

First scan for codes, see what comes up. This should be the first step .

 

[Tomspassat]

It's not constant, just sometimes. I should have time this weekend, car runs fine otherwise.

 

[Tomspassat]

No codes, hm, what should I do now?

 

[chittychittybangbang]

Are there a lot of bubbles in the fuel line? If so, it could be air causing stumbling. Also check all the vacuum llnes. If they are chaffed, then it could be causing some running problems.

 

[diesel guy]

I just thought that if you have any modifications to the car, you could be try leaning out the fuel.


Adjust the IQ so that the displayed number is higher. This will give it less fuel and it could change the stumbling.

 

[chittychittybangbang]

Ah, right. I am working on a writeup on the relationship between nozzles size, pump size, chip, and IQ.

It's all so interrelated with other stuff too that it's hard to organize all the info

 

[jon applespeed]

Could be a vacuum line, but I think that a vacuum line issue might set a code.