recently I have been experiencing some sort of an odd problem. I start up my car and it idles perfectly fine but when taking off my car will jerk almost like I am on and off the throttle, this happens through all the gears. if I put my foot to the floor and accelerate quickly it won't do it at all, it's only under low throttle/slow (low rpm) acceleration. Once the car warms up (a couple minutes of driving) it goes away completely. At first I was thinking my tb was getting stuck but now i'm thinking coil packs. I ordered another set of coil packs today and will try them out.

Any other suggestions?

fwiw I put a new iacv on it so I can rule that out.

 

Changed my coil packs, didn't help

 

I think it's the IAC valve especially if it's happening at lower RPMS.

 

Doesn't happen at idle though, and it's a new iacv

 

Did you check the spark plugs, clean the MAF sensor? Maybe you're just going too low in the RPM range.

 

Mine does that occasionally, I put it down to a very sensitive accelerator pedal, the ecu having different timing while the engine is cold and with my foot soo lightly on the pedal that any movement from the car causes the jerkyness.

My car has 42k just been fully serviced and drives as it should the rest of the time, but if there is a fault I will be sorting that so if others can confirm anything

 

have you tried resetting the ECU?



i would also check plugs if you havent already, we dont have a MAF sensor. did you check your droop or throttle cable deflection?

 

I haven't checked plugs yet but I will be replacing them for good measure. My car is also on the stock comptech supercharger so i'm gonna check my belt tension again as well. I'm pretty sure it's not my throttle cable, it's nice and taunt and i'm not sure that would explain why the symptoms go away when the car warms up either.

 

It is definitely not coil packs.

Be sure your throttle cable is not over tightened also.

 

any other suggestions?