Mechanics

CHEVY TBI FLOODING

1993 Chevrolet Suburban

Engine problem
1993 Chevy Suburban V8 Four Wheel Drive Automatic 130000 miles

My burban stumbled the other day and then the SES light came on. When looking at it with the air filter off and the key to on with the truck not running the drivers side fuel injector is spraying fuel and flooding that side. I replaced the fuel injector and got it to start. Drove around the block was ok I parked it for the night, next day went to start it and it had the same problem as before. What is going on here?

The truck has a 454
Avatar
Oldchevyscadillacs
December 6, 2007.




If your fuel injector is spraying fuel without the engine running, then the computer is most likely malfunctioning.
The fuel injector should not spray fuel until the cylinder calls for fuel. If the engine is not rotating then no fuel should come out of the injectors.

Tiny
Pear69
Dec 6, 2007.
I did disconnect the battery when I changed the fuel injector so I could charge it on the bench. Then re installed it. Thats when it started up with out the check engine light. Will the computer reset it self when you disconnect it like that? Does it sound like my fuel injector is good, along with the fuel pressure regulator? Is there any way to test that on the TBI?
If the fuel regulator went bad could it blow the injector and force the fuel out through it? Any way to test the ECM? I dont have any friends with a 454 suburban or truck from the early 90's to trade with.

Tiny
Oldchevyscadillacs
Dec 6, 2007.
  A fuel injector works on electronic pulses sent from the computer. When these pulses are received the injector sprays fuel. The timing of these pulses is congruent to the rotation of the motor, especialy the cam shaft. It's not like the old days of balancing the carb. So the fuel mixture is right. The computer does all of that for you--or--it's supposed too!   If the fuel regulator went bad the fuel would not be forced through the injector. The injector needs electricity to open and let fuel through. If the fuel regulator was bad, when the injector electricaly opened, more fuel would flow through. In order for the injector to open the cam must tell the computer to send an electrical pulse to the injector so fuel can be sprayed, at the right time, through the right injector, on the right side.  

Tiny
Pear69
Dec 6, 2007.
So I could test this by disconnecting that injector and turning the key to on, Then there should be no flow through it because the signal from the assumed to be bad ecm couldnt tell it to open?

Tiny
Oldchevyscadillacs
Dec 6, 2007.
Yes sir.
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Tiny
Pear69
Dec 6, 2007.
Is there any way to have the computer checked out before I spend $$ on a new one?

Thank you for the help too !

Tiny
Oldchevyscadillacs
Dec 6, 2007.
Yes, absolutely have the computer checked out. If you can find a garadge with the proper scan tool ( a tech 2) it may be cheaper then going to the dealer; but a dealer has the proper equipment for this. A tech 2 scan tool, or the equivalent, is necessary to test your computer. Keep me posted

Tiny
Pear69
Dec 7, 2007.

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