69 427 - Chevelle Tech
Troubleshooting Diagnosing problems done here.

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post #1 of 22 (permalink) Old Jun 23rd, 19, 10:54 PM Thread Starter
 
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69 427

Was running okay after recent build and had electric pump set to low adjustment while idling went on test drive, believing had a vapor lock after cooling started heading back, started popping back with noise, taught it was a bd rocker or something now can’t get it to stop popping thru carb
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post #2 of 22 (permalink) Old Jun 23rd, 19, 11:07 PM Thread Starter
 
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I checked compression and all good, roller cam, 800 Holley, really need some ideals
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post #3 of 22 (permalink) Old Jun 24th, 19, 12:13 AM
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Re: 69 427

you will need to check the distributor for movement, if it loosened?
distributor cap and rotor for cracks and broken tabs?
check your timing if the first 2 are ok...

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post #4 of 22 (permalink) Old Jun 24th, 19, 1:50 AM
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Re: 69 427

Check float levels. With too low of pressure you may be starving for fuel.

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post #5 of 22 (permalink) Old Jun 24th, 19, 9:22 AM Thread Starter
 
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I pulled the plugs all liked basically good not wet, before drive I set fuel pressure to about 6, pulled valve covers nothing visually unusual, thing is before I left on drive it was running good, then it sounded like almost a loose rocker, now spitting and popping no flame
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post #6 of 22 (permalink) Old Jun 24th, 19, 11:38 PM
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Re: 69 427

Quote:
Originally Posted by 65vet56belair View Post
I pulled the plugs all liked basically good not wet, before drive I set fuel pressure to about 6, pulled valve covers nothing visually unusual, thing is before I left on drive it was running good, then it sounded like almost a loose rocker, now spitting and popping no flame
i would check the distributor for movement, if it loosened?
distributor cap and rotor for cracks and broken tabs?
check your timing if the first 2 are ok...

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post #7 of 22 (permalink) Old Jun 25th, 19, 1:28 AM
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Re: 69 427

Quote:
Originally Posted by 65vet56belair View Post
Was running okay after recent build and had electric pump set to low adjustment while idling went on test drive, believing had a vapor lock after cooling started heading back, started popping back with noise, taught it was a bd rocker or something now canít get it to stop popping thru carb
Recent build you say ? what kind of lifters did you use,flat lifters or roller lifters ?

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post #8 of 22 (permalink) Old Jun 25th, 19, 11:54 AM Thread Starter
 
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Rollercam,
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post #9 of 22 (permalink) Old Jun 25th, 19, 11:55 AM Thread Starter
 
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With it popping don’t like starting it,
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post #10 of 22 (permalink) Old Jun 25th, 19, 12:25 PM
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Re: 69 427

A valve staying closed? Check your lash.
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post #11 of 22 (permalink) Old Jun 25th, 19, 12:51 PM
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Re: 69 427

one can write in complete sentences and something that resembles English, even on a smart phone......
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post #12 of 22 (permalink) Old Jun 25th, 19, 2:51 PM
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Re: 69 427

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Originally Posted by blue_69_malibu View Post
one can write in complete sentences and something that resembles English, even on a smart phone......
I think spell correct stung him a few times there
to the OP usually popping back thru the carb is an ignition misfire or an intake valve not seating.Try to see if you can isolate it to one cylinder hopefully. In this case a vacuum gauge might help you find out whats going on.
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post #13 of 22 (permalink) Old Jun 25th, 19, 3:49 PM Thread Starter
 
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Sorry about the spelling I quess. I’m just looking for a bit of insight..... I will start over; recent build, distributor is a Dui, roller cam, basically a 427 l88, timing was set and running decent, had issues with vapor lock by fuel line running by headers, took on test drive roughly 1 mile, after leaving gas station it vapor locked, cooled off and restarted, afterwards started popping almost sounded like a rocker let loose, found it to be noise bouncing off air filter top, trouble keeping it running and towed it home, checked rockers none loose, but did not reset them, checked compression and plugs both looked good
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post #14 of 22 (permalink) Old Jun 25th, 19, 3:50 PM Thread Starter
 
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How would I isolate, can’t keep running with popping
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post #15 of 22 (permalink) Old Jun 25th, 19, 4:16 PM
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Re: 69 427

Have you done ANY of the diagnostics suggested above?
Float level
Timing set at?
Do you have full 12 volts at the distributor (Resistance wire not in play)?
Rotor not broken or not seated properly?
Valves set too tight?
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