Posted: 6/14/2012 6:17:19 PM EDT
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I have a 1985 K30 with a newer 350 that was previously in a 1992 Chevy van. The tow truck driver I bought the engine from had it rebuilt and installed it in the van less than 20k miles ago.
Since taking it from the van, he swapped it over to a normal intake and carb. After installing it into my truck, I added a new Edelbrock 600cfm carb. Under a load, it makes a rattle/ping/ noise. It's not bad under normal cruising, but under a load it gets much worse. We've set the timing at everything between 0 degrees and 8 degrees. It seemed to get worse the higher the timing is set. Setting the timing down to 0 or 2 makes the engine tick at idle. I recently added some octane boost helping that was the problem, however, I don't notice any change. The truck is a single cab longbed, 4" lift, cut fenders and 37's, and 4.10 or 4.56 gears. It's an auto with a Turbo 400 transmission, disk break swap, etc. It's my daily driver/ farm use truck. Any ideas what could be causing the rattle/pinging noise? I need help! |
| If it still has the 92 distributor, then it needs an older one, probably just your standard late-70s to mid-80s GM HEI setup. The 92 distributors were all computer controlled as far as controlling advance is concerned. If your current one does not have the little metal pot on the side with a vacuum line going to a vacuum source, you have the wrong distributor. |
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Quoted:
If it still has the 92 distributor, then it needs an older one, probably just your standard late-70s to mid-80s GM HEI setup. The 92 distributors were all computer controlled as far as controlling advance is concerned. If your current one does not have the little metal pot on the side with a vacuum line going to a vacuum source, you have the wrong distributor. This or running lean on the main jets. Or both. |
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not to mention you can't just slap a carb on top and expect it to run like a top.
check what is listed above, if you find that the distributor is not vacuum advance controlled and have to replace it, get a vacuum guage, a tach and read up on vacuum tuning, it's rather simple. take it for a drive and see how it runs and check the plugs to see what the mixture looks like. if by chance that engine has a magnetic timing tube on the front cover, which i doubt, a timing analyzer would be handy in making sure your distributor is advancing properly. you might also have to look at different rods or jets depending on how your engine responds. i.e. back in 96, i had a 78 cadillac escalante. 350 old block and mpfi. computer went bad so i converted to carb. had to change distributor and intake and add a mechanical fuel pump. got it dialed in with the exception of a little lag on take off. dropped in slightly larger rods because those were easier and lag disappeared, from what i recall anyway. my 2 cents. |
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Quoted:
Quoted:
If it still has the 92 distributor, then it needs an older one, probably just your standard late-70s to mid-80s GM HEI setup. The 92 distributors were all computer controlled as far as controlling advance is concerned. If your current one does not have the little metal pot on the side with a vacuum line going to a vacuum source, you have the wrong distributor. This or running lean on the main jets. Or both. It's been switched to an HEI distributor, not the factory 1992 one. I'm leaning towards it running too lean under heavy throttle/load, so I guess I'll learn how to change the metering rods and jets in an Edelbrock carb. |
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Quoted:
Quoted:
Quoted:
If it still has the 92 distributor, then it needs an older one, probably just your standard late-70s to mid-80s GM HEI setup. The 92 distributors were all computer controlled as far as controlling advance is concerned. If your current one does not have the little metal pot on the side with a vacuum line going to a vacuum source, you have the wrong distributor. This or running lean on the main jets. Or both. It's been switched to an HEI distributor, not the factory 1992 one. I'm leaning towards it running too lean under heavy throttle/load, so I guess I'll learn how to change the metering rods and jets in an Edelbrock carb. They make a kit that has several different metering rods, jets, and springs in it. You might try just replacing the spring for a softer one before going the rod/jet combination. Edelbrocks are crazy easy to change. You don't have to pull the carb apart to change the rods or springs and just the top comes off to do the jets. You don't even spill fuel. |