Acceleration jerking part II

[BZY247]

Looks like a trend this week with the ****** acceleration problem.


It started doing a slight stutter a week back, just a slight spot when around 4k rpm, then went away, then it started to get worse and worse. Today it was doing it through every gear and through all of the rpm range.

I ruled out fuel pump as it was still boosting and car can get up to and past 100kmsw without too much of a problem. It also starts fine and idles normal.
I checked for any vacuum leaking and it was fine. Spark plugs were only replaced a few weeks ago before it was doing this. And AFM was cleaned properly also.

At the moment the car sounds like a wrx, so i can assume its running on 3cyls

I can only assume its the leads?? Will inspect tomorrow and report.

Meanwhile anyone else can suggest a possible solution/idea to this issue ?

 

[BMGTZ]

put a wide band on it to check afr....

check for boost leak. tester can be made cheaply or borrow

 

[Atters_del]

Its been suggested to me to check my timing.... Im having the same problem but yours sounds worse... good luck with the fault finding. Oh when i unplugged my AFM my engine light came on about 3 mins later so least it was working

 

[Gianni]

If its running on 3 cyls I doubt it's timing. Most likely as been mentioned, leads, or the spark plug itself, or the injector.

One thing I've had before us the igniter plug wiggle loose whilst driving. Sometimes would pop off other times just loose connection for a second, but that wouldn't cause it to run on 3 cyls

 

[CLuTZ]

Like the others have said, start off with the basics... ignition system/boost leaks etc. Especially around the j-pipe coming off the turbo. If you're running aftermarket tune or ECU then your plugs can be fouled in 2 mins let alone 2 weeks! Always pays to pull them so you can tick them off the list.

 

[Gianni]

Yeah, I destroyed mine in 3 seconds once I changed cams

 

[BZY247]

the trouble was in one of the leads. changed all the leads and it runs now better than it ever did. Never knew a set of new leads could make such differance. Then agaun who knows how old the original leads were . . .