s4 gxl and I replaced the injectors, fuel pump, afm, and the intake gaskets and vacuum lines. The compression is good its 85 to 90 across the board and it has new plugs and wires. I can get it to start if I floor it but it won't stay started unless it sits above 3k rpms. I haven't checked the tps yet but the cas looks good acoring to the fsm. I can rev it to 10k+ but below 3k it stumbles and crashes and won't stay started. Any Ideas would be a big help thanks.

 

Could be tooooooo many things to count. Such as the lower grommets on the fuel injectors not seating. Spray starter fluid under the intake manifold in the direction of the primary fuel injectors. Oh heck, secondary also.

Could just be a big *** air leak, as in leaving the air feed line to the BAC off/loose etc. Or since this is a non turbo, the half inch in size air hose at the bottom of the BIG intake duct is off. God only knows. Big *** airleak covers it.

 

WTF??!!???

Why would you do this?

How do you know it will rev this high?

Is there something done to the motor?

 

I checked everything hailers2 suggested weeks ago but no success. I replaced everything afterwards and still no success. I know the motor will rev that high because 50k ago the previous owner had the motor rebuilt by pineapple racing and they put hardened apex seals on it and did a street port on it.

 

Did HAILERS clone himself?

 

Dolly the sheep has nothing on me. And I'll live a lot longer than that ewe.

Maybe there's something real simple wrong? Trail coil wires crossed? Does it run better with NO Trail plugs on ? Or injector wires/plugs crossed? Ehhhhhh. Not that likely on a non turbo, but possible. No original thoughts at the moment. CAS rarely, and I mean rarely fail.

Sounds a bit like a apex seal cracked/broken.

 

wouldn't the compression read low on one of the rotors if the apex seal was broken. I tried removing the trails with no success.

 

Is the AFM plugged in? Sure sounds like un-metered air entering the intake. Look closely for unplugged air hoses and check all clamps.

 

I've plugged and unplugged everything over and over again. I replaced the whole afm after the problem occurred.

 

I have a video of what its doing I wish it had the throttle readout but it doesn't. The video can be seen at http://www.youtube.com/watch?v=9SNjiA14Qag

 

sorry i didn't really read much i just saw this post cause rx7club is my homepage. try checking your ignitors one of them is probably bad it happened to me.

 

Wow...to me that compression sounds low, a lot lower than it should on a fairly recent rebuild.

 

thats definitely not caused by un-metered air. un-metered air would cause the engine to "bog" before stalling out, not just quietly stop running like in the video. its most likely something electrical. ie the coils, the injectors, or the tps. those would be my main guesses.

 

thanks I replaced the injectors they are brand new because thats what I thought but it just ran a little better. The coils are getting spark but I don't know if its enough.

 

I checked the compression too its right at about 90.