Ok, I'm lost on this one, I still need to change out the intake manifold gasket, but here goes. Mark and I just got my car running "properly" although it seems to run a little rich still. It would run fine. I have a Top speed intake mani and the holes are plugged in the bottom, the back two are hooked up, but it sounds like their is a leak somewhere. I can't quite feel it, nor can i squirt at it without seeing(with soap/water). It certainly seems to be on the intake manifold side though, because you can hear it coming from there. ALso if this helps, when it did run consistently it would backfire when i revved it to 3k. Any help is appreciated, thanks.

 

are you running a filter, is your mafs just hanging out open?

 

Ya, it's a 300zx mafs with a filter. AND yes it is hooked up correctly haha

 

haha, I've just seen stubling idle caused by mafs turbulence before, simply because there was no filter. I'd think that an intake manifold leak (sucking in air after the mafs) would make it run lean as hell. You might try the usual idle killing suspects, like IACV, coolant temp sensor, very retareded timing (off a tooth), maybe O2 sensor. Do you have the vacuum reference hooked up on the FPR?

 

Check for leaks, as mentioned in the 'manifold' thread, I have heard problems of the manifold flange being a little 'warped' and have also personally experienced it myself on a Greddy manifold. Have you messed with the idle control valve?

 

If it backfired at 3k, it would be the maf, 99%. Wired up correctly? Maf's good?

 

Its backfiring through my exhaust.

It HAS to be wired correctly, Mark wired it about 4 different times, if he wired it the other way, it would smoke heavily out the back.

It runs rich and I still need to 1. replace the exhaust mani gasket and then replace the intake mani gasket.

It could be the timing, but well I'm not quite sure...

 

make sure you are set to TDC pull the valve cover. pressurize the intake manifold with an air compressor.

 

Well I just replaced the intake manifold gasket, and it still is struggling. Anyone wnat to come out here and help me out? I'll gladly pay if the problem is resolved. I just have no idea what is going on since it was idling fine before, then all of a sudden it doesnt want to stay on.