mwpayne

Found and fixed original no-fuel issue by fixing bad fuel pump connection. Now, however, the idle 'hunts'. No vaccum leak that I can find with carb cleaner spray. I'm going thru the FSM now, but I'd sure appreciate some tips as I'm fairly familiar with 1st and 2nd gens, but my boy's 3rd is giving me a migraine.
It's got a power FC with stock map, if that helps, all emissions removed. Compression fine as well, can only get 5lbs of boost at around 4-5K, then it begins to 'cut out' with black smoke. It acts like a leak, but damned if I can locate it.

I'm betting it's a simple fix if I can find it. Thanks in advance!

Sacker90

Car is also on stock twins non-sequential...

mwpayne

Bump for gurus...

2rotors

i am currently having a similar problem...i fixed a bad connection at the fuel pump...and also wasn't boosting properly...after a long head ache i was checking all the vaccum lines and found one that when i gently pulled on came right off...put it back on with a zip tie and no more boosting issues...as for the black smoke ...still have that...at times the car becomes hesitant jumping idle...some times shuts of...i attempt to rev it out and somtimes takes a while... SO IF ANYONE CAN HELP US....PLEASE DO.... THANKS!!!

mwpayne

Surely someone has run into this and come up with a solution or two..

edwin-82/rx7

iTrader: (1)

What are you idle settings on the pfc? Also there is a screw on the throttle body to adjust idle, try searching for "idle adjustment" or the like.

The plastic crossover pipe from the turbos to before the intercooler is known for cracking on the bottom side. It really sounds like a boost leak. Try a search for "boost leak" and see how others have located them.

Sacker90

The crossover pipe is in good condition and all vacuum lines seem to be intact...The car runs better at before 50 degrees Celcius and after that, thats when it starts to run the worst...The idle on the pfc is set at 900 rpms.

edwin-82/rx7

iTrader: (1)

sounds like something is heating up and expanding, allowing air out somewhere...

clayne

mwp:

And how long ago was the emission equip removed and converted to non-seq?

xblazinlv

You need to adjust your idle air bleed screw under the elbow on the throttle body.

clayne

Yep - that's a likely source - IF he just made the changes. If it just appeared out of the blue when the changes have been there for a while - that's something else.

mwpayne

Could I trouble you for a pic so I'd know just where that screw is?

xblazinlv

Sorry I don't have a pic handy, but if you take the elbow off, you'll see there is a hole right under the throttle body. You have to use a flat head screw driver to turn it.

clayne

Once again. Did you just make the changes or has the car been running and operating fine previous to this?

RaPtOr-T

You must take off the elbow to get to the screw, dont try and find it with the elbow on, you wont Once the elbow is off it should be pretty obvious, its a screw in a hole

mwpayne

This car has been pretty much running like this since he's had it. so it's nothing that's come up recently. Thanks for the guidance, I'll look for that screw this evening when he brings the car home. Could that be the cause of the boost issues as well, or just the idle?

xblazinlv

Nah, it's just the cause of idle surge issues sometimes. Not boost issues


What kind of boost issues are you having?

mwpayne

This be the boost issue. I hope to have the car here enough next week to do some serious troubleshooting. I'll post what I find/don't find. I really appreciate the help, once this is taken care of it'll be for sale. Got to have something better on gas for school/work!