1993 Chevrolet Silverado carburator

Tiny
SEAN030888
  • MEMBER
  • 1993 CHEVROLET SILVERADO
  • 5.7L
  • V8
  • 4WD
  • AUTOMATIC
  • 2 MILES
Hi I sprayed carburetor cleaner in my carburetor. I fired it off and it started. The truck has sat 5 years. I changed the fuel filter. It is getting as going through. I left the front line off and turned the key. It shot fuel through at full strength. I replaced the battery is this the carburetor and what can I run through it to maybe clean it out. Can I use seafoam. Thanks.
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Thursday, January 29th, 2015 AT 3:53 PM

11 Replies

Tiny
CARADIODOC
  • EXPERT
What kind of problem are you trying to solve? You don't have a carburetor. You have a throttle body which is nothing more than a throttle blade and an idle speed motor.
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Thursday, January 29th, 2015 AT 4:01 PM
Tiny
SEAN030888
  • MEMBER
When I spray carburetor cleaner in the throttle body it fires off then dies so is it the throttle body. If so what can I use to clean it. Can I use sea foam or what is a good product. If it doesn't work I will have a mechanic fix it.
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Thursday, January 29th, 2015 AT 4:09 PM
Tiny
SEAN030888
  • MEMBER
Can I use acetone to clean out the throttle body or is it going to be to harsh. Thanks.
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Thursday, January 29th, 2015 AT 4:48 PM
Tiny
CARADIODOC
  • EXPERT
The only thing you're going to solve by cleaning the throttle body is a hesitation on acceleration, or a low idle speed. Even the low idle speed is pretty much a thing of the past with the better additives in today's fuels. That was caused by carbon build-up in the air passage around the throttle blade. GM never had a lot of trouble with that.

If you're not getting fuel, that has to do with the fuel supply system and the injectors. No fuel goes through the throttle body. Normally I would say to not get hung up on the first thing you find missing, meaning fuel, and check for spark too, but since it runs on starting fluid, we can assume spark is okay. Most no-start problems are caused by missing spark AND injector pulses.

Removing the fuel line isn't conclusive either because you need to know exactly what the pressure is. A lot of GM vehicles won't start if the pressure is just a few pounds lower than specs. Typically they call for around 45 to 50 psi. In the classes I attend, they always talk about low fuel pressure on GM trucks, and the cause is a weak fuel pump, but I don't know how common that really is.
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Thursday, January 29th, 2015 AT 5:37 PM
Tiny
SEAN030888
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Ok I just might have my mechanic look at it for me. Thanks I appreciate it.
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Thursday, January 29th, 2015 AT 5:39 PM
Tiny
SEAN030888
  • MEMBER
When I look at the trucking don't see fuel test ports its not like the newer ones. I have a 1992 Cadillac deville and it has test ports. Where you just screw the gauge in. On this how would you test fuel pressure.
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Thursday, January 29th, 2015 AT 5:51 PM
Tiny
CARADIODOC
  • EXPERT
If you have a complete fuel pressure gauge kit, there should be some tee fittings in there. Look for the rubber hose that connects the steel line on the body to the fuel rail. That's where the tee is inserted.
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Thursday, January 29th, 2015 AT 5:57 PM
Tiny
SEAN030888
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Ok this is with the truck off look at the fuel gauge. When I start it it does the same thing.
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Thursday, January 29th, 2015 AT 6:15 PM
Tiny
CARADIODOC
  • EXPERT
During that time period GM used an unusual gauge design that had two electromagnets in it. The weaker one pulled the needle to way over "full" and the stronger one pulled it back down based on the resistance of the sending unit in the tank. A broken ground wire or rusty tank strap can cause a loss of ground for the gauge, and that often results in a dead pump too.

I'll be back in the next day or two to see how you're doing.
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Thursday, January 29th, 2015 AT 6:26 PM
Tiny
SEAN030888
  • MEMBER
Well gave up on it had my mechanic look at it. He said it was the fuel pump. I figured it was but wasn't sure. You were right thanks for all the help.
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Saturday, February 14th, 2015 AT 9:56 PM
Tiny
CARADIODOC
  • EXPERT
Dandy. Happy to hear it's solved.
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Saturday, February 14th, 2015 AT 10:04 PM

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