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Discussion Starter #1
I have an idea what I may need to do from reading previous posts, but would like to hear what anyone has to offer. I am having trouble with my new motor backfiring through the carb. I have been able to get it to idle, but when I hit the throttle a little, it backfires and shoots flames out of the secondaries. I have not adjusted the valves yet, have an HEI with stock module, the motor dies and backfires through the carb when I close the choke, and backfires through carb when I give it some gas. Is it as simple as changinh the module and adjusting the valves???
 

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I would adjust the valves for sure, then see how it runs. The good thing about a valve adjustment is that its free! I hope you have it running good soon!

Jerry
 

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Your problem 'sounds' like the timing is retarded quite a bit. Popping, spitting and backfiring thru the carb are very typical when the initial advance is retarded several degrees. Try advancing your timing and see if it clears up - hope it cures the problem.

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Chevellz Alwayz!
 

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I could be all wet, but it seems to me to be more of a carb problem. Possibly the accelerator pump in the carb is not shooting enough fuel when called for.
 

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Discussion Starter #6
Thanks guys!, If I were 180 degrees out, would I still be able to start the motor at the turn of a key? I thought that might be the problem at first, but the motor idles fine. I do need to finish up adjusting the carb. Spitting, popping and backfire through the carb is exactly what is happening. I need to adjust the valves..any suggestion on the best procedure? I am having trouble hearing the "ticking" over the exaust. Any suggestions on valve adjusting would be appreciated.
 

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66 El Camino 57 Chevy pickup 2004 Tahoe
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First, I would go throughthe plug wires/firing order. Real easy to get #5 and #7 mixed up. Ditto for 4&6. Then check the timing with a light. Look for 10 degrees BTDC or so.

If you have a hydraulic cam, there's no good reason to adjust the valves with the engine running. If you're not up on a good method of doing it with the engine off, re-post here and I'll give you a good setup on how to do this.

Tom
 

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Discussion Starter #8
Thanks Tom, I will check those wires tommorrow. I have just read a few posts and the tech reference regarding adjusting valves, and I am now questioning if I may have taken too much "slop" out of the push rods. I followed the "spin method", when I probably should have just taken the slop out and then turned 1/4 turn. I do have hydraulic lifters, so I think I will follow the procedure outlined in Tech Refenrence. Thanks, I hope to be up and running soon.
 

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Discussion Starter #9
Hello again!!
I adjusted the valves as reccommended in the tech reference and it made all the difference in the world. After playing with the dist., I was able to get the motor started. No more problems with backfire through the carb and I can really hear the "Lopey" sound of the cam/exhaust. The first time I adjusted the valves using the pushrod "spin" method. That was the problem as all of the rocker nuts were tightened down too far. Thanks a million!!!
 

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66 El Camino 57 Chevy pickup 2004 Tahoe
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1Quik7D

cool deal. The pushrod spinning deal can take a little practice to get used to, I sort of slop it up and down while twisting it so I know when it's getting close. Now that you've got your car fixed, hang around. There's lots of stuff to learn here. Lots of experienced people, whatever you need to do to your car, there's always somebody around who's done it, learned the pitfalls and is willing to pass along a little info. The longer I'm here, the more impressed I am with the depth of knowledge and team spirit.

Tom
 

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I am glad to hear that the valves did it. I have seen that problem before. It's amazing what problems they can cause. Sounds like a nice running engine!

Jerry
 

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Discussion Starter #12
I was running the motor this evening and I can hear a little bit of "ticking" from the rockers. Is this just normal or should I adjust a little bit???
 

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You might try adjusting them again. Or, at least make sure they are all properly adjusted. Your valve train shouldn't make a lot of noise. Have a great weekend.

Jerry
 
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