I have a 89 iroc 5.7 w/ a maf style TPI.The problem I'm having is a rich fuel mixture and a no start condition when hot. The car starts 1st crank when cold just turns over when warm.My starter turns over fine its not being heat soaked, New dist., new coil, new heated 02 sensor (long tube headers), new spark plugs, havn't changed wires 95% sure that they are fine, have fuel, 44lbs at the rail, good compression, for some reason still getting an orange spark. Battery is new, I have already ohmed the inj., (15.0), knock sensor is good, maf is good, cts is new. I have also verified that the car is reaching open loop. No matter whenever I try to start the car after it is warm (right after shut off up to about 20 minutes) I have a no start condition. Computer is not showing any codes ses light does work. She runs great even when warm just wont start after being shut off. Running out of ideas appreciate any help or suggestions that anyone may have thanks!!

 

does the car run rich when it does operate, run

 

yes

 

i would START withe ohming out your injectors, cold, then hot, see if any drop off, also i would check the vacuum lines comming off the FPR for fuel in them, also, an orange spark is USUALLY a weak spark, your wires are probably coroded inside. also, try clearing the computer after its hot and wont start, remove the battery cables and touch them together to discharge the system, then reattach them, see if it starts.

 

havnt changed the wires yet but i ohmed the injectors cold and hot 15 ohmes across the board. ive been told that doesnt mean there not leaking but if they were i dont think it would affect a restart right after shut off. I dont think there would be enough time for it to leak down and flood. Ill check that fpr vacuum line idea now.

 

i forgot to mention that i pulled the fuse out of the ecm to clear it already after warm. I know it cleared because i let it get up to temp with the tps unpluged to see if it would throw a code and it did. Pulled the fuse for about a minute turned the key on and the code was clear.

 

no fuel in vac line should i get it to temp first

 

just turning the key off with clear most codes, at least it does on mine, try a full ECM reset

 

il give it a shot

 

full rest didn't work. tried resting IAC control now the car won't start at all.

 

ok, something tells me your IAC is shot, its probably getting heat soaked and stuck closed after you shut it off, then when it cools it opens back up again when you try to strt it, i'd replace that iac

 

changed the wires & she fired right up after charging the battery. Not sure why it started it seems to be that if I roll it over and doesn't catch the first time it never catchs at all. Again waited 15 minutes and she fired up, shut her off immediatly and no start again. Thanks for the idea's that have already been given. ruled out everything I already have been told too, any other suggestions no matter how small before I blow up my car lol!

 

are the injectors firing during the no start?

 

never actualy checked i would guess yes cause i smell fuel.

 

I HAD THE EXACT SAME SYMPTOMS. TOOK IT TO THE SHOP, THEY SAID THE INJECTORS WOULD LOSE RESISTANCE WHEN TESTED HOT, THEY WERE RIGHT I INSTALLED NEW INJECTORS EVERY THINGS GOOD NOW. MIGHT WANT TO CHECK INJECTORS AGAIN. GOODLUCK

 

well i took it out for a ride (first time this season) and got a steady misfire couldnt tell what it was but im pretty sure its got to do with the spark. I bought cheap wires just to check and make sure my msd wires were good. Im going to try switching them back and see if im still misfiring. Maybe im loosing an injector while im running? Like i said ohmed the injectors cold and hot and got 15 across the board so i'll try again tommorrow. Would a vacuum leak do it? Ive even tested the volts on my coil along with ohmes. Im starting to get frustrated!!!!!!!.

 

does not mean its not clogged or not firing, pull a plug from each cylinder 1 ant a tme till you find the one not firing, could be a fouled plug, a bad wire, a bad cap, or you canhave really weak spark

 

i pulled a wire off every plug and there was no change. Even had my father in law watch the tach. whats up with that?

 

theres so much unburnt gas it was giving me a headache last time i took it out. dont know if that helps or not.

 

the only thing i have not replaced in the ignition system is the spark controler

 

hmmm

 

HAVE YOU CHECKED THE IGNITION MODUEL, HEAT CAN EFFECT THAT. ALSO CHECK YOUR TIMING, NEVER KNOW MAYBE MOVED, TPI NEEDS TO BE 6 DEG BTDC DONT FORGET TO DISCON TIMING WIRE.

 

ARE YOU SURE YOU DONT HAVE AN INJECTOR LEAK? THE WHOLE SMELLING FUEL THING DOESN'T SOUND GOOD.

 

....catalytic converter, ill bet you ANY MONEY it's plugging up. drop the cat, run it till its nice and hot in your driveway and try to restart, also get a look into yer cat and see if its plugged, if so, hollow that bitch out, and keep on driving, also if he had an injector leak, he would lose pressure, and new dizzy's come with new ICM's, and ICM failure usually causes cut outs, not cranking issues.

 

The Cat clogged ? What does one do to alleviate this if this is the case?

 

Thats funny, I run 17* base timing with premium and no knock what-so-ever!

My newer formula has a similar hunting issue, but no starting issues. I have to look some more and see what others think. Good luck on your car!

 

replace it

 

guuh.. dufus who put my exhaust on welded it on... wtF>>!>!>!

I've got cut outs anyway, will run it like tht and see if it helps.

 

cutouts are cool, but if you have exhaust like mine, you don't need cutouts, right? I put some videos up on you tube too

 

I had a problem alot like yours the car ran fine ,then hot sometimes it didn't want to start and if it did you couldn't even see behind you for the rich smoke. A friend of mine used a snapon com to test and found the comp. in the car was bad. I replaced it know it works fine, maybe this could help (good luck)!!!!!!

 

You stated your fuel pressure is at 44 psi. I want you to do a test. Run the car with your fuel pressure guage connected and note the pressure. Then leave the guage on and shut the car off. Does the pressure drop to zero right away? If it does the nozzles on the injectors are leaking. The pressure should not drop to zero with the car off. It does you found your problem.

Injectors can ohm test ok but still have leaking nozzles. The ohm test only checks injector coils not the nozzles. I have seen this several times.

Also after you shut the car off and it will not restart pull a spark plug. If the plug is soaked with gas this also confirms it.

 

Someone PLEASE HELP. 85 305 TPI IrocZ I' stuck. Lost. Confused PLEASE PM ME
ok so Timing was at 16 and now set to 7.good, tps is now adjusted properly,perfect voltage.good, Fuel Pressure is here we go:43 KOEOff, at idle too. Start revving and drops a bit, the higher i reved though it would drop more. I revved it to almost WOT and it dropped to 20 for split second and goes right back up. Fuel filter was clogged BADLY and installed wrong way from whoever long ago. Changed that and put it in right way and well, drives descent now untill gets warmed up/hot. Then its right back to crap/ nothing past 1/4throttle. Now i've heard that the oil pressure switch/sensor controlls power to pump after runing for a minute or so. Also the codes i've got out of it was 42 EST Fault and 44 Lean exhaust. But the light goes off if I drive around slowly and just grandma it. I tested the HEI/EST according to printout and I think it tests ok as far as coil but the cap itself, all the terminals on the D. Cap whre plug wires go on are ALL LOOSE, like prettty loose. Thats not normal is it. SO sorry so long, but am I still having a fuel issue or is it spark related being the EST code was thrown momentarily right after trying to be hard on gas. I've done so much diagnosing I'm soooo confused but I've gotten quite far with it but now am lost though. I also put IAC/air mixture Idle screw at proper setting and idles great so I'm gettin somewhere just not good enough. Any help would be great. Thank you so much. God Bless You