85 corvette tpi, running rich, black smoke won't idle ideas? Help
06-21-2011, 11:02 PM
#1
85 corvette tpi, running rich, black smoke won't idle ideas? Help
I have a 85 corvette that runs rich and wont idle, dies when i let off the gas. The car throws no trouble codes. I have two different proms ive tried and they make no difference. I have a otc scanner, multimeter, and injector pulse tool, among other tools to check components on the car. Below is a list of the things ive checked today with no change in the running of the car, any advice is appreciated.
*injectors all ohm at 16.5
* injector pigtails from harness all read 12v
*Injector pulse tool bleeds all injectors from 46 to 40 psi they all bleed the same which eliminate the possibly of leaking injectors???
* timing set at 6 degrees and verified
*fuel pressure set at 46 psi
*tps voltage at .58v at closed throttle
*coolant temperature sensor pigtail reads 5v, cts reads correct resistance for the varying temperatures
*valves adjusted correctly.
*new spark plugs and plug wires
*02 circuit working, always reads .6-.8 volts(rich of course, but does very) cross counts working in scanner
*does go in to closed loop
* less than 2000 mile old oxygen sensor.
*iac pigtail voltage 11.8 (key on)
*injectors all ohm at 16.5
* injector pigtails from harness all read 12v
*Injector pulse tool bleeds all injectors from 46 to 40 psi they all bleed the same which eliminate the possibly of leaking injectors???
* timing set at 6 degrees and verified
*fuel pressure set at 46 psi
*tps voltage at .58v at closed throttle
*coolant temperature sensor pigtail reads 5v, cts reads correct resistance for the varying temperatures
*valves adjusted correctly.
*new spark plugs and plug wires
*02 circuit working, always reads .6-.8 volts(rich of course, but does very) cross counts working in scanner
*does go in to closed loop
* less than 2000 mile old oxygen sensor.
*iac pigtail voltage 11.8 (key on)
06-21-2011, 11:13 PM
#2
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Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: 85 corvette tpi, running rich, black smoke won't idle ideas? Help
Have you tried/checked a new MAF?
06-22-2011, 07:52 AM
#4
Re: 85 corvette tpi, running rich, black smoke won't idle ideas? Help
Checked the maf by switching it out to another, no difference. Took the prom out completely and it wont idle but does run cleaner and doesnt smoke. That doesnt make sense because the prom has worked fine in the car for over a year. Im thinking a faulty ecm? Or maybe not, ideas? Thanks
06-22-2011, 08:18 AM
#5
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Car: 1989-92 FORMULA350 305 92 Hawkclone
Engine: 4++,350 & 305 CIs
Transmission: 700R4 4800 vig 18th700R4 t56 ZF6 T5
Axle/Gears: 3.70 9"ford alum chunk,dana44,9bolt
Re: 85 corvette tpi, running rich, black smoke won't idle ideas? Help
Mafs can fail without setting a code..
Wow odd problem. Id like to get my hands on it 2 check it out!
Off the top of my head, check your vac line an see if it has raw fuel in it. If so your regulator diafram has gone bad and is leaking fuel up in the manifold.
Wow odd problem. Id like to get my hands on it 2 check it out!
Off the top of my head, check your vac line an see if it has raw fuel in it. If so your regulator diafram has gone bad and is leaking fuel up in the manifold.
06-22-2011, 08:46 AM
#6
Re: 85 corvette tpi, running rich, black smoke won't idle ideas? Help
checked afpr just now, no fuel in the line. When i had the prom burned i had the egr deleted out of the program. However the valve is still on the intake i wonder if the diaphragm has gone bad, making me have a internal vaccum leak, making the motor run rough and be constant rich?
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