Bucking....

[joeym4130]

I have a quick ?....
My car is bucking badly when i accelerate....I thought it was a boost leak, I didnt get to check yet, but it bucks under any acceleration, even when not in boost....so i am thinking its not a boost leak? I have a bad ISC, replacing soon, but I didnt think my faulty one could cause bucking, I am going to check plugs tomorrow and wires. Any other things to look for?? I can only stop the bucking if I just touch the throttle lightly...as soon as i give it any good amount of gas it will buck. Maybe timing too? thanks!

 

[iwin]

Change the ISC and check all of your intercooler piping.

 

[Sephroth57]

that sounds like an intercooler leak to me because when youre accelerating slow it doesnt buck thats cause theres not enough pressure for the leak to be a problem. soon as high pressure starts going through your pipes its shooting out the leak and causing bucking. do the leak down test in the intake section of VFAQ

 

[joeym4130]

ok i'll do a test. thx
but i dont know if that could be it... like I mean the only time it will not buck is if I just like feather the throttle...most light touch i can muster. As soon as I put any more on the throttle it will buck, even at like 2k rpm. Any other sugg??
Hopefully I just have to tighten the IC pipes

 

[CurtTSI]

Originally posted by joeym4130

Sounds more like plug wires or plugs to me.

 

[joeym4130]

shoot! just got in from outside...checked plugs, look fine and gap is good. Didnt check wires...what are good methods to do so? i hear running in the dark and looking for arcs, but is there a way to check like the resistances or something? thx. Oh yeah..I know the ISC is bad, but would that cause bucking under normal driving??

 

[turboholic]

Originally posted by joeym4130
i hear running in the dark and looking for arcs, but is there a way to check like the resistances or something?

-Wire can be check with a multimetre for resistance, I can't tell you what the value are for each wire because manufacturers different and length of the wire, you can look up the #s in the manual if you're using the wire set from the dealer, as for looking for arcs, you have to spray fine mist of water on the wire in order to check it. I agree with others that you have a boost leak, could be on the pipes, hoses or intercooler itself.

 

[eclips4g63]

Im having the same bucking problem as you are..thought it might be the wires guess i need to check for a boost leak

 

[joeym4130]

All is good again! I think one of the plugs were F'ed... the previous owner had them gapped real large, i put them down to .028 and di-electric grease on the wire and plugs. I think one of the wires was making a bad connection and after pulling and putting the grease on them she runs great! thx!