tbi mystery.gurus needed! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dmartin1 · 02-11-2013, 08:02 PM

1992 1 ton c3500 with a TBI 454. Just replaced the fuel pump and injectors.I put in used working injectors. It fired up and ran awesome. The next day I go to start it and its flooding the engine bad to where it will try to fire a hit but won't run.and backfires through the intake a lot when I touch the pedal. I just tried a few junkyard intake coolant sensors and still the same. The pigtail lead off the sensor has a fairly big area with no insulation on it but its not broken. I replaced the fuel regulator and still the same.
It was just running fine yesterday!

I pulled plugs and gas went flying out.after sitting hours and new spark plugs still the same. Any suggestions?? Please any advice is appreciated.
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ChevyTech · 02-12-2013, 12:56 PM

Unplug the wiring from the injectors, crank the engine, and see if any fuel drips from the injectors.

Let us know what you find.

The o-rings could have gotten damaged, or misplaced, when you changed the injectors.

dmartin1 · 02-12-2013, 04:00 PM

nah,dry as a bone when off. trys to start though but wont

dmartin1 · 02-12-2013, 05:02 PM

everything works as it should except it just sprays a TON of gas into the engine. after extended cranking trying to start i pulled the spark plugs cranked it and a can full of gas shot out of the cylinders and out the exhaust. i will do a oil change etc io know i shoiuld,but need to figure this out first.

it ran perfect the time i put the new injectors in it then i tried starting it the next morning then bam flooding

ChevyTech · 02-12-2013, 05:17 PM

If the injectors do not drip any fuel when you run the fuel pump with the injectors unplugged, then the problem is very likely the coolant sensor that the ECM monitors or the wiring to it.

Make sure there are no broken ground wires at the front of the intake.

I would take a scan tool and look at the coolant sensor temperature.

02-11-2013, 08:02 PM	#1
dmartin1 Registered User Join Date: Aug 2008 Location: mohave valley,arizona Posts: 1,088	tbi mystery.gurus needed! 1992 1 ton c3500 with a TBI 454. Just replaced the fuel pump and injectors.I put in used working injectors. It fired up and ran awesome. The next day I go to start it and its flooding the engine bad to where it will try to fire a hit but won't run.and backfires through the intake a lot when I touch the pedal. I just tried a few junkyard intake coolant sensors and still the same. The pigtail lead off the sensor has a fairly big area with no insulation on it but its not broken. I replaced the fuel regulator and still the same. It was just running fine yesterday! I pulled plugs and gas went flying out.after sitting hours and new spark plugs still the same. Any suggestions?? Please any advice is appreciated. Posted via Mobile Device __________________ 1969 Shortbed in progress 1982 short step, few suspension and motor upgrades.getting a 468 1978 Shortbed fleet side bonanza fully loaded 1978 k20 Silverado loaded.currently engine-less 1989 k10 suburban 9" lift 65 nova And more

02-12-2013, 12:56 PM	#2
ChevyTech Registered User Join Date: May 2004 Location: Minnesota Posts: 4,621	Re: tbi mystery.gurus needed! Unplug the wiring from the injectors, crank the engine, and see if any fuel drips from the injectors. Let us know what you find. The o-rings could have gotten damaged, or misplaced, when you changed the injectors. __________________ For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If it is modified from what came stock from the factory, let us know that too.

02-12-2013, 04:00 PM	#3
dmartin1 Registered User Join Date: Aug 2008 Location: mohave valley,arizona Posts: 1,088	Re: tbi mystery.gurus needed! nah,dry as a bone when off. trys to start though but wont __________________ 1969 Shortbed in progress 1982 short step, few suspension and motor upgrades.getting a 468 1978 Shortbed fleet side bonanza fully loaded 1978 k20 Silverado loaded.currently engine-less 1989 k10 suburban 9" lift 65 nova And more

02-12-2013, 05:02 PM	#4
dmartin1 Registered User Join Date: Aug 2008 Location: mohave valley,arizona Posts: 1,088	Re: tbi mystery.gurus needed! everything works as it should except it just sprays a TON of gas into the engine. after extended cranking trying to start i pulled the spark plugs cranked it and a can full of gas shot out of the cylinders and out the exhaust. i will do a oil change etc io know i shoiuld,but need to figure this out first. it ran perfect the time i put the new injectors in it then i tried starting it the next morning then bam flooding __________________ 1969 Shortbed in progress 1982 short step, few suspension and motor upgrades.getting a 468 1978 Shortbed fleet side bonanza fully loaded 1978 k20 Silverado loaded.currently engine-less 1989 k10 suburban 9" lift 65 nova And more

02-12-2013, 05:17 PM	#5
ChevyTech Registered User Join Date: May 2004 Location: Minnesota Posts: 4,621	Re: tbi mystery.gurus needed! If the injectors do not drip any fuel when you run the fuel pump with the injectors unplugged, then the problem is very likely the coolant sensor that the ECM monitors or the wiring to it. Make sure there are no broken ground wires at the front of the intake. I would take a scan tool and look at the coolant sensor temperature. __________________ For those of you that are wondering why you are not getting replies to your thread: Did you give the model, year, engine, fuel system type, and transmission information? If it is modified from what came stock from the factory, let us know that too.



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