love the forum just never signed up i wanna thank everyone without reading wouldnt of done my gas tank fuel pump and intake gasket.But after i just installed my intake gasket truck runs real rough wont even stay running without being on the gas backfires like crazy and will take 10 minutes to get to 30 mph i figured timing when i had the distributor out my mechanic took care of that and after 2 hours of tests told me it was multiple vacum leaks in the manifold but ive read were a lot of other things give the symptoms i have like fuel pressure regulator any advice or thoughts and i would be grateful

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sorry forgot to add its a 96 ls 4door 4wd

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also when they checked the compression it was 180 psi on all cylinders


*EDIT by swartlkk* - Combined consecutive posts. Please use the edit feature to add additional information to your post if another member has yet to reply. Thanks!

 

sorry forgot to add its a 96 ls 4door 4wd

 

also when they checked the compression it was 180 psi on all cylinders

 

Will the engine idle? Does it idle high?

If it will idle, you can use an unlit propane torch to diagnose vacuum leaks. By moving the torch along all of the gasket mating surfaces around the intake and listening for changes in the engine's speed, you should be able to pinpoint the vacuum leak.

A leaking fuel pressure regulator would cause a rough idle and general poor performance. Typically it will result in a hesitation and not normally in back fires...

 

yea it is the vacum leaks they seem to get better not good just not as horrible when the truck hits its normal operating temp it will idle shortly but stalls out would there be a possibility i could fix it with out ripping it apart maybe i didnt torque correctly or in the right sequence or something although i did go for 11 ft lbs but the torque wrench is a piece of crap