car jerks, bucks, spitts and sputters

[rlacasse1]

heres my problem. my car has run fine til lately. now it is slow and it will start jerking real hard around 4200 rpm. ive read through the forums and i tried all the things that i saw mentioned. ive changed the spark plugs. tried 2 different types of plugs. stuck with the NGK's ### they made it run a lil better. i changed the plug wires. i have also changed the fuel filter. can anyone give me any ideas on what i should try now.

 

[talonDSMerr]

Are you throwing any CEL's? I had a similar problem, turned out my TPS had gone bad.

 

[tenn-gsx]

Do a boost leak test.

 

[ryu 2042]

Do you have a Bov? And more importantly is it recirculated?

 

[Dsmj89]

Do a boost leak test, make sure all your hoses are tightened down good. Also make sure to recirculate your bov if you aren't doing so.

 

[UGOT8UP]

Throw a timing light on it.

 

[rlacasse1]

First. thank you for the replies.
The car has no CEL's and is completely stock. I havent tried a boost leak test but i will. And the BOV is recirculating. If its not a boost leak then what else might it be?
thanks for the help

Ill check out the TPS to

 

[98gst14b]

Definatly try a boost leak test before anything else, boost leaks will make your engine behave like you mentioned. Heres a link to a homemade how-to that I've tried and works well. IC Pipe Tester

 

[wvturbo2]

If boost leak test doesn't fix it. I'd pull the ecu and make sure it doesn't have any leaks or problems.

 

[90on35psi]

Make sure the plug wires are plugged into the coil all the way. Also check the plug for the transistor pack and the plugs to the fuel injectors. ECU could have leaky caps too. Just hang in there because these things can be very frustrating.

 

[markdr7]

I had this same problem the other day. It ended up being the upper intercooler pipe was really loose and creating a huge boost leak. I agree with everyone else do that boost leak. The first time I did one I found leaks everywhere.

 

[phill4g37t]

hey guys im having the same problems too although mine is a bit more complicated my car starts jerking and shaking like crazy, the car is losing power when i put the car in 1st. i also changed the fuel filter, i have no boost leaks since my car is an n/a 1.8 also checked for exhaust leaks found none and my tps is also working fine what else is there to check and fix.. im p.od ### i cant figure out whats wrong with it.

help please

 

[rlacasse1]

ok ima check the boost and i was gonna try changing out the coil pack but couldnt find the one off my other car that we stripped. neway i dont think its gonna be the ecu ### i just put in a new one

i checked out that link. looks like a good idea. thanks