Hesitation when cold and light throttle

[ViPER1313]

Car is a 1990 TSI AWD Turbo. When my car cold (about the first 5 minutes of driving) I have a pretty noticeable hesitation at lower RPMs and light throttle conditions. When you press the gas about 1/4 of the way down or less, you can hear the turbo spool abnormally loudly but there is no momentum change, then all of a sudden the motor will "catch" and you get a jolt of acceleration. Heavy throttle conditions don't produce nearly the same hesitation. It goes away almost completely once the car has reached operating temperature.

Plugs and wires are new, no boost leaks (tested), ECU has been re-capped, engine / chassis and battery leads are clean, new PCV valve. I also sprayed the MAF with cleaner - it made no difference. Car runs fine when it's warm.

TPS? Engine temperature sensor? I'm open to troubleshooting suggestions.

 

[Lofty]

5 speed or manual?

Maybe the trans is on the way out.

Sounds kinda far fetched but the "catch" sounds like something transmission wise is slipping.

 

[XiKeiyaZI]

An automatic transmission can do this from time to time. When's the last time that you changed fluids in it? I had a similar issue in my Stealth - I drained the fluid, changed the filter in the trans, replaced everything, and it was as right as rain from then on(excluding I can't get the damned thing to run correctly).

Besides that, can you share any other details? Recent changes? Did it just suddenly start acting up like this?

 

[ViPER1313]

The car is a 5-speed and the clutch is not slipping at all. The engine revs don't build when the condition occurs. No recent changes - the car has done this since the day that I bought it over a year ago, and doesn't seem to be getting any worse. I just figured it was about time to fix the issue

The engine doesn't buck or run rough when this occurs - it feels like you left the e-brake on and then suddenly let off of it. It's almost like the car is bogging down from too much fuel, like a 2-cycle engine when you first start it and give it a quick stab of gas.

 

[wishin4nX]

Pretty sure it's an exhaust leak. My girls gsx does the same in neutral,as I didn't get her a new gaske for the o2 housing/14b.but durin cold starts until it's at temp if you light throttle it then it hesitates to go up in rpms, and then after a second it revvs up.

 

[And_44]

Ever find out what this was. I know holy revival batman. But curious as I have same issue. Thinking of a timing issue.

Well, I may of found my reason. Thought I had checked timing when I got car but probably was previous one I checked. My ignition timing was at *10 BDC readjusted to *5 TDC and car runs sooooo much better. Guess being *15 off does effect things.

 

[98gstbrad]

Is the egr valve deleted because that could cause this problem by opening when its not supposed to.

 

[And_44]

Got rid of the problem for a bit but recently returned. Yes, my EGR has been deleted and blocked off.

Believe it's a maintanence item as it was gone for a period of time after I did a whole list of stuff to car. Now going to go back and do some more.