91 tbi wont fire, fuel pump works
05-10-2017, 10:30 AM
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91 tbi wont fire, fuel pump works
my 91 rs auto started acting funny about a month ago, i started it and i ran like complete crap, you had to give it throttle to keep it running and it was running pure rich, you could really smell the raw gas smell. if you let of the gas it would die and you would have to hold the pedal to the floor and let it roll over for a while till it wanted to fire, now last night i wanted to start it and move it and it wouldnt start at all, just rolls over, i can hear the pump running when i turn the key on or when i let off the starter it will cycle for a few seconds till its back up to pressure but dont seem to be spraying fuel, if you give it a shot of ether it will want to try to start. where should i start with this issue?
05-11-2017, 09:24 AM
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Car: check
Engine: check
Transmission: check
Re: 91 tbi wont fire, fuel pump works
Spark plugs are likely fuel fouled, hence the no start.
Check two things, what the ECM is seeing from the CTS for engine temperature. And with the fuel pump running see if the injectors are leaking fuel (bad o-ring), or if the FPR is leaking fuel (bad diaphragm).
RBob.
Check two things, what the ECM is seeing from the CTS for engine temperature. And with the fuel pump running see if the injectors are leaking fuel (bad o-ring), or if the FPR is leaking fuel (bad diaphragm).
RBob.
06-29-2017, 09:23 AM
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Car: 1994 454 big block jet boat
Engine: mild build BBC 454
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Re: 91 tbi wont fire, fuel pump works
I had an issue where my fuel injectors were "stuck" and wouldn't fire I tapped them both with a screwdriver handle and it un-seized them. Problem solved. if you aren't spraying any fuel then the injectors are very likely the issue.
If no spark, the Ignition Control Module under the distributopr cap is likely the culprit.
Of course you could just buy my custom TBI I have for sale if all else fails...
https://www.thirdgen.org/forums/engi...-2-barrel.html
If no spark, the Ignition Control Module under the distributopr cap is likely the culprit.
Of course you could just buy my custom TBI I have for sale if all else fails...
https://www.thirdgen.org/forums/engi...-2-barrel.html
06-29-2017, 10:03 AM
#5
Re: 91 tbi wont fire, fuel pump works
An engine running somewhat rich produces a lot of carbon monoxide (CO) which is colorless and odorless.
An engine producing eye-watering "rich" fumes is probably misfiring, including LEAN MISFIRE. Anything that causes the cylinder of air/fuel to not burn produces a huge amount of hydrocarbon (HC) emissions.
An engine has to be gargling on gasoline for a running cylinder to produce as much HC emission as a misfiring cylinder.
Just because the electric motor driving the fuel pump runs, does not mean it is delivering fuel to the injectors. Test the fuel pressure.
An engine producing eye-watering "rich" fumes is probably misfiring, including LEAN MISFIRE. Anything that causes the cylinder of air/fuel to not burn produces a huge amount of hydrocarbon (HC) emissions.
An engine has to be gargling on gasoline for a running cylinder to produce as much HC emission as a misfiring cylinder.
Just because the electric motor driving the fuel pump runs, does not mean it is delivering fuel to the injectors. Test the fuel pressure.