Help, hesitation issue. Rotary mechanic was stumped.
 

Well aparently after a few weeks of my car being at Rotorsport I will be picking it up tomorrow. Paul was unable to figure out what was causing the hesitation around 3k rpm. He said he replaced pretty much everything and it still eluded him. Dizzy, ecu, plugs/wires, AFM, etc. I think once I get it back I am going to try doing better grounds but other than that I have no idea. So if anyone has any ideas that would be greatly appreciated. Its an s4 t2 with a streetport. Thanks guys.

actually my car has the same prob and as soon i go up to my buddies shop www.aimtuning.com to pick up my exhaust ill let ya know what was wrong with mine and it could possibly be the same as yours.

run some fuel system cleaner ...can't hurt ya.

Sounds like the 3800 rpm hesitation, which is caused by bad grounds.

And an 88 TII doesn't have a distributor.

I'm suprised that rotorsports can't figure it out. And also i think throw parts as such (CAS, ECU, etc) is the incorrect way to diagnose a symptom. I would think they would do better then that.

-Justin

If they couldnt figure that out...they got problems. That hesitation is the most common problem with FCs.

Check all the grounds. Clean them up or replace the cables. Make sure all the mating surfaces are clean metal to metal contact.

And a big LOL at the replacing of the dizzy! HAHAHA! They REALLY must not know what they are doing!

Haha Im sorry about saying dizzy I ment coilpack but I was tired I swear! I know its not the 3800 rpm hesitation because I have had that before and know what its like. this is more around 2500-3300. It just doesnt want to rev freely. Paul said he tried everything and eventually just started throwing parts at it cause he had run out of ideas. I should get it back today or tomorrow and I will let you guys know if the ground fixes it.

i went to my tune shop yesterday to put my apexi gt catback exhaust on and i talked to them about it and they said it could be 1 of your 3 cats that ise plugged up

Grounds...
Either ECU grounds are no good, or bad engine grounds causing low voltage, bad spark, etc.


-Ted

Check the TPS. The WOT and no throttle positions need to be checked, but also the transition between them. Slowly sweep the range of the TPS and see if the numbers jump irratically. You'll need to use a digital meter or better yet an oscilloscope. Do it a few times to verify what's going on.