Long story short last fall I developed 2 large vaccume leaks after the MAF, one in the elbow and another at the TB gasket and at the same time the car had a terrible upper RPM miss. All the common culprits were changed, coil, wires, plugs, fuel filter, etc etc. Needless to say until I found these leaks none of these helped. As the miss and Im assuming the leaks got worse the cars performance took a big nose dive at the track.

Now can someone tell me for sure if two big vaccume leaks after the MAF can cause an upper RPM miss and loss of performance? Ive asked before and never got a straight anwser. I would say yes but thats just me.

Anyone? I wanna try to figure this out.

 

Ok.....im not sure exactly, but my intake elbow had 2 leaks in it as well a while back. It had a cut on the side, and on the very bottom, I didnt know until I took it off, but the bottom part folded up into the TB, so there was a big gap. Luckily I have a scanmaster, and noticed my BLM's were way off. Someone suggested to check it, and sure enough it was torn. I put a new one on there, and sure enough my BLM's went right back to normal(128). But I still had the same high rpm miss. I didnt plugs and wires next(one of the plugs was pretty damn bad)..and it stopped "surging, hesitating" at high speeds....but it was still slow at high speeds(like on the highway over 80 mph). It didnt get better, but not back to par. I actually think this was because i could only change 7 outa the 8 plugs. I gotta order a better tool to get outa the last one.

So sorry I didnt answer your question because I had like 3 problems at once....if anything else, this is a TTT....but yes, having a vacuum leak is going to affect your speeds power and speed...how much im not positive, but it will.


Also, I just ordered 2 new O2 sensors..ill let ya know if that solves any of my problems. I noticed you didnt change those...but if I recall correctly those go into limp mode under WOT so I dont think they should give the problems you're having.

 

How come you don't just fix the leaks? Can you just not find them?

 

Oh they were fixed but the next day the TPS took a crap on me and before I fixed that the car went away for the winter.

The miss would only happen at WOT and predictably starting at 5500 RPMs or so. Never in part throttle driving or in the lower RPMs at WOT.

 

ahhh i c... have you taken a look at your blms lately? I don't think your symptons would cause a miss like your describing.. I think you should start looking into plug wires.

 

Plug wires were changed and miss didnt go away.

 

Anyone know? shoebox? Injuneer?