1987 Chevy Silverado Fuel Problem?

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CALLISTO
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  • 3 POSTS
New to the forum, and hopefully I can get this issue resolved.

First off the truck is a 1987 Chevrolet Silverado 1500 (G10? K10?) 4x4, 5.7L V8. The engine is *supposedly* new, with less than 8000 miles, but some friends have said that it looks like the original engine. If its the original then it has around 180,000 on it. I have dual gas tanks.

When turning the truck on, it has to crank for a good 5 seconds before actually turning over. Once it turns over, and the key is let go, it dies almost immediately. To get the truck to run the gas pedal has to be pressed down a little just after after it turns over, and it can continue to run after that on its own. Also, until it is really hot, the engine idles up and down. Is this normal?

To me it sounds like the TBI is not getting gas for a little bit after start up. My question is what are the most likely problems, and where can I find them. I have replaced the battery, and cleaned the terminals. I have been told that the engine should turn over almost immediately, and that would be absolutely great if it did. I am really hoping that it is not the fuel pump(s), because we are currently in the midst of another vehicle with a dropped tank and rotted fuel/brake lines. Not fun. Anyway, hope someone can lend some help. Thanks.
Aug 22, 2007 at 5:32 PM
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RASMATAZ
  • ✓Experienced Mechanic
  • 75,988 POSTS
[quote:2d178a1882="callisto"]New to the forum, and hopefully I can get this issue resolved.

First off the truck is a 1987 Chevrolet Silverado 1500 (G10? K10?) 4x4, 5.7L V8. The engine is *supposedly* new, with less than 8000 miles, but some friends have said that it looks like the original engine. If its the original then it has around 180,000 on it. I have dual gas tanks.

When turning the truck on, it has to crank for a good 5 seconds before actually turning over. Once it turns over, and the key is let go, it dies almost immediately. To get the truck to run the gas pedal has to be pressed down a little just after after it turns over, and it can continue to run after that on its own. Also, until it is really hot, the engine idles up and down. Is this normal?

To me it sounds like the TBI is not getting gas for a little bit after start up. My question is what are the most likely problems, and where can I find them. I have replaced the battery, and cleaned the terminals. I have been told that the engine should turn over almost immediately, and that would be absolutely great if it did. I am really hoping that it is not the fuel pump(s), because we are currently in the midst of another vehicle with a dropped tank and rotted fuel/brake lines. Not fun. Anyway, hope someone can lend some help. Thanks.[/quote:2d178a1882]

The CEL is it coming On.

Inspect and test the CTS/PCV and EGR valve. Comeback with your findings. We'll get to the fuel system and its circuitry later.
Aug 22, 2007 at 9:11 PM
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CALLISTO
  • MEMBER
  • 3 POSTS
The check engine light does not come on.

I just checked all the little vacuum lines over the top of the engine and none seemed to be leaking. To be honest I have no idea what the EGR and PCV valves even look like. If you could tell me what they look like, where they are, and how to check them out I could. I have searched the internet but can't find very much info.

For your information I just used the truck, and it was really hot when I parked it 20 minutes ago. I just went out to check the vacuum lines, and it took 3 tries before it was able to start and run on its own.
Aug 23, 2007 at 1:28 AM
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CALLISTO
  • MEMBER
  • 3 POSTS
I found a great site to tell me how to check those things. I now know what they look like.

Do I need a pressure gauge to check if the EGR valve is bad? The line going to it does not have vacuum at idle. I raised the RPM and checked and there was some vacuum. What else do I need to do to check the EGR valve, or is that it?

I checked the PCV valve by unplugging it out of the engine and it has vacuum, and hisses, so that is OK.
Aug 23, 2007 at 2:15 AM
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