holley power valve

[70dusta]

hey my cars started runnin really shitty at low rpms and backfiring out the carb like crazy. its a 318 with a holley 650 on top. it runs good a mid-high range rpms and i didnt touch the timing so i dont think its that. i was talkin to some one and they mentioned the power valve blowing out on backfires and im pretty sure its blown (i tested it) could this be my backfiring problem or is it sumwhere else thanks for ur help i really wanna ge this thing on the road so badly

 

[68gts340]

backfire is usually ignition, the blown power valve is a result of the backfire, not the cause..start going through the ignition and electrical system, verify every thing. if the plugs are really sooty black with carbon replace them too.

 

[grumpuscreature]

Ran across this a time or two myself. Pull the vacuum line off the distributor and plug it (golf tee works good). Hook up your timing light and start the car. If the timing mark on the damper appears to be moving back and forth any at all, change the timing chain.

 

[moper]

Double check you dont have a burnt plug wire. Does it idle at all? Puke black smoke when at idle? Did it start this all of a sudden, or did it progessively get worse? If you think it's in question, for $7, just replace it. I'd probably just rebuild it (I like the AED kits..everything is reusable...) at the same time if it's older than 2-3 years. As they mentionned too, it may be a symptom, not the cause. Verify your timing chain hasnt jumped if the engine over 50K miles on it, verify the timing curve and it's parts in/on the distributor are working properly. (a timing tape for $3 will go a long way to checking this stuf with a std timing light)

 

[70dusta]

hey everyone i needed a carb replace neways (20yearoldholleywasnt cuttin it for me) so i picked up a edlebrock 66 performer series slapped it on zand now my car is runnin mint so im pretty phyced thanks

 

[69signetv8]

Glad you got her working, now it 's time to fix that pic dude...it hurts the eyes :glasses7: