Hesitation and jerking

Would anyone have ideas as to what may cause hesitation and jerking when stepping on it. I'd be driving normal then I'd step on to pass, but before it would pick up and go it will hesitate and jerk a few times.

I have an 02 TDI Golf with auto tranny.

Any suggestion?

Could be a number of things. What nozzles do you have? Could be bad nozzles. How long ago did you change your fuel filter? How are your boost levels reacting? Is your car seriously over-boosting?

To me, it sounds like you either have a leak in your turbo control lines, or you need a new fuel filter. If you are sure that these aren't the issue, I'd look at your nozzles. Maybe run a can of Diesel Purge through your engine. Can get a can from Precision Tuning (Steeles and Keele). There are some write-ups here on how to properly run the stuff through your engine.

I have also seen bad MAF's exhibit those symptoms. But seeing as you have an Auto, it could also be the transmission. They are not known to be the best.

Well I have smog 205's and the last time it has done that the boost was at about 18psi. I also have a vaccuum gauge on the fuel line and it's been no higher then 9 hg, so I think we could rule out the fuel filter.

Wingnut;

Is there away to test to see if it's the tranny?
If I step on it from stopped it accelerates very well no hesitation.
Does that say anything?

Do you have a boost gauge? Do the boost levels correspond with the jerking?

How about engine RPM, any correlation there?

I hope these aren't another set of the JBM nozzles... The hesitation could it be as simple as a sticking vnt actuator or turbo veins.

Pay close attention to the boost when this happens. Also, when you "step on it" is the car downshifting, or staying in the same gear? If it is downshifting, then you may have an auto tranny on the way out. I say MAYBE...don't go sweating about it yet.

If you can replicate the issue, please give more specifics. The Smogs shouldn't really be giving you any issues. VNT actuator might be a cause, but if you get proper boost right away, then it's something else.

Yes I have a boost gauge and the boost was at about 18 psi when the jerking occurs, I did not see any correlation. So I think I'm getting the proper boost. I'll replicate the issue and give more details if I have more.

The tranny stayed in the same gear when it happens, when it down shifts it takes off well after.

Thanks for the input so far.

Your Sig shows "fuel pump advanced" what kind of timing do you get in VCDS? to far advanced can cause a hesitation when you really lay into it.

I've had the fuel pump advanced for well over 100 000km, the timing is near the top of the timing chart on vag com

I had a similar problem with my 5speed, MAF tested ok, I eliminated everything else, problem still occured. I replaced MAF, problem went away. Seems like early signs of MAF failure.

Great, I've been trying a few things. I cleaned the snow screen which was almost completely blocked, then problem is less frequent but still occurs. I'm watching boost pressure and fuel line vacuum, all is good. I'm now going to order a new MAF and we'll see how that goes.

Thanks everyone, I'll post the results when this is replaced.

Well if you guys have seen my thread about my tranny you know what I'm saying by my tranny issue.
It seems (only after one day of driving) that after my tranny issue the hesitation and jerking has stopped. Maybe by resetting the TPS that may have solved this issue as well. We'll have to drive for a while to be sure.

Thanks for all the input and I'll post on this issue again if it comes back.