IM very confused, my turboII will not allow me to give it more than 5% throttle, in any gear. if I do the car bucks, backfires, and just wont go.

I have 2 vacuum nipples exposed that I know of, and the idle is surging at 1500 rpm. What the hell is going on??? Timing is correct.

its a s4 tii

 

AFM is pooched.

Cap the vac lines also if you want to take a shot at making the idle smooth.

 

O RLY?? I suppose that would be a possibility. Any way to test it?

yeah im sure that vac lines are the source of the idel, just havnt got around to pulling the upper intake to fix it

 

There's a procedure in the FSM for testing the resistances, but the best way really is hook up with a buddy who has a spare (or just a working one) swap them out (about 3.6543minutes) then fire it up and see what happens.

 

i talked to gary brooks and he thinks it could be the blow off valve too

 

causing the idle problem or the bucking?

Because at minimal throttle the car shouldn't even be boosting, so how is the BOV affecting that? unless it was leaking or something - but chances are it wouldn't be as violent as bucking, more of just a miss.

 

afm or blown off intercooler hose.

 

yeah he thought the diafram could be messed up. But its any time I open the secondary throttle plates, it bucks and hesitiates

 

Check for boost leaks, and if there's none and can prett much assure you that the AFM is pooched.

This makes it sound more like the AFM, since you aren't even really making boost at that instant...it takes a little more time.

The only thing I can say is you either have a number of vac leaks (well you obviously do because you know of exposed nipples) or the AFM is shot - or both.

The vac leaks will turn into boost leaks when it goes into boost, right? Unless its got a check vavle inline like the brake master - so button up all those little gremlins and see how it runs.

 

Check the TPS

 

you could simply unplug the maf and drive the vehicle if it drives the same it most likely is the maf, but you need to take care of those vaccuum leaks before you can accurately diagnose anything like this

 

hmmm... it sounds like its misfiring. me car was doing the same thing. then i noticed a spark jumping from the wire to the coilpack (trailing coil.. i think). the i checked my wires. and one of em was fried at the plug...

thats just my 2 cents..

 

well im going to knock out the vac leaks this weekend, and my buddy has got another afm I can try. I'll report back.

 

do you know what a MAF is???

 

When I had this issue, it was because I needed to re-wire my fuel pump.

 

have you checked your tps setting? surging can very easialy be traced to an out of adjustment or faulty tps. check all vaccume lines, intercooler piping for leaks, as well as test the coils and plug wires for proper operation.

 

yeah, unplug your AFM and I'll bet it won't buck anymore...but that's because it won't run.

 

rewire the fuel pump huh? i'll give that a shot, i just installed a walbro 255 not too long ago

 

did you try the AFM yet?

 

gonna try this weekend.