starts fine. runs briefly and shuts off. no idle

[rx7 FC TII]

ok so i just got my car running again for the first time in about a month. i had 2 clogged injectors and i couldnt get it to start.

so after installing some 75lb secondaries, clean and flowed my primaries, new injector clips all around and an rtek 1.7 ecu it was running fine and no problems for the past 24 hours. on the drive home today it was fine...till i pulled into the neighborhood.

i downshifted into 2nd and it almost shut off. i got it home and it sputtered down stayed alive then died. i noticed some smoke right before it shut off so i popped the hood and jumped out to check...no fire.

i started it again and it starts just fine but as soon as it starts if i dont give it gas it dies and if i give it enough gas to stay over 1K rpm then its fine. under 1K it smokes out the exhaust.

also i checked for error codes and there are none. im thinking its something to do with ignition and the smoke unburnt gas?

im also going to do a compression test tomorrow. and i have sent an email to rtek to see if the symptoms sound like its the ecu malfunctioning. would you get an error code if it was the ecu?

[RoughRex]

I've seen this happen if there is a big intake or vacuum leak. Too much unregulated air into the engine causes it to die when the ECU switches to the AFM after startup.

[IndyParts]

Originally Posted by RoughRex

I've seen this happen if there is a big intake or vacuum leak. Too much unregulated air into the engine causes it to die when the ECU switches to the AFM after startup.

+1

Look around the intake and see if you don't have a loose clamp or something of that nature. Sounds like you have a large leak.

check for a leak around the AFM... otherwise any vac leak will cause this.. since this is a turbo check all your couplers to see if any have fallen off or pushed back off the pipe a bit causing a leak

[RotaryXperiment]

+3? for vac leak.
if u can find someone to hold throttle and listen around for hissing or spray starting fluid around intake manifolds and vac lines.

[TehMonkay]

Vac leak or variable resistor

[rx7 FC TII]

haha 3 different forums 3 different ideas of the problem.

ive ordered an ecu and im gonna get some help saturday to check for leaks.

ah after 3 years of working on this car and i still feel like a newb.

what would cause the ecu to get fried like that? just old condition?

[DBXJ]

Mine did the same thing right after the new motor go put in it turned out that one of the plastic barbs on the vacuum splitter for the OMP lines broke. would start run for about 5 sec and shut down even if i give it gas

[Eatmyclutch]

Have you tried tweaking with the TPS?

[NoDOHC]

The injector vacuum seals must be replacd when replacing the injectors, if you did not do this or they were not installed properly, you will have a vacuum leak under the injectors.

Try flooring the car and see if it revs ok.

[rx7 FC TII]

all the seals are brand new and replaced.

im assuming they are installed correctly cause its running now with no problem.

[Max777]

lol, I had the injector vaccum leak problem: I got some 3/8 vac line, cut it a bit thicker than the vac seals, and presto! PS: Do get some silicone 10mm hose if you can, it's a better alternative to fuel hose...

[rx7 FC TII]

oh man. dont get me started on the venom injectors.

so far i havent had any more problems with it.

[NoDOHC]

out of curiousity, what was wrong?

[rx7 FC TII]

haha if i could answer that i would.

im assuming it was a vac leak

i drove about 75 miles today with no problems so i guess it worked it self out. maybe it just needed some new gas and a good interstate run.