im working on a 99 it had pump codes in the ecm so i put a new pump on and it has no codes at all now but it has the same problem still if you try to gas it hard it falls flat on its face has new lift pump on it, it will rev up no load to 3000rpm no problom but under a load it goes to about 1500rpm easy after that it it fall flat I check the turbo its good its like its not telling the pump to turn up the wick it will rev up but it slow to act even in 2nd gear.im lost to what it could be, any help is great help

 

have you unpluged the programer yet and tryed, after that id say turbo, boost boot, inercooler problem. try those but this could be related to the poping in the idal so my be injectors??

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sorry you have the same pic as another guy on here disregard the idle problem

 

Check for codes?

 

What is the fuel pressure at when it falls on it's face like that.

When you installed the new pump did you also replace the overflow bypass banjo bolt on the VP.

 

heyguys not sure if this might be a problem but the fuel realy in the fuse box under hood might be going bad

 

could be the apps sensor needs adjusted. sounds like its possible what it is. might try adjusting them. good luck. let me know if ya need any help, im bout an hour and a half from ya. im over in yellville.

 

ya did it doesnt have any codes now

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its got a new overflow bypass to im at a losse im going to look at the aaps today, iv never seen this problom before

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I THINK IT HAD TWO PROBLOMS at the same time pump being one of them and the other? idont now i thankyou all for the help im going to go look at the apps

 

How about fuel pressure numbers. Those Holley pumps are kinda iffy. Some guy's runin em for years with good results and some have em crap out within days. So fuel pressure numbers could be key to keepin this new VP runnin good. Both idle pressure an WOT pressure.