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Discussion Starter #1
got a issue that started back a couple months ago, been trying to figure it out, here's what ive done so far , replaced maf, iac oxygen sensors ,coils, and new accell injectors, fixed a vacuum leak on egr valve gasket yesterday but still have the issue , when i get in car after it sets for more than a hour and crank it up idles fine other that the rpms tend to hang a bit seems like , but anyway when i go to put the car in reverse and pull out of yard the rpms start to bounce way up to like 1500 then down to like 500 ,if i dont get on the gas pretty quick it stalls ,yesterday it did this and stalled and was kinda yard to restart , starting to think it may be fuel pump failing ?

---------- Post added at 11:47 AM ---------- Previous post was at 11:44 AM ----------

also replaced fuel filter
 

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If I read that correctly, with the motor cold it idles OK in high idle (1100-1200 rpm) until you apply a load (put it in gear) then the idle drops to 500 rpm and stalls if you do not work the gas. I believe you said you replaced the IAC. Did you adjust the TB butterfly valve?

New TBs and even old TB with some wear and tear need to be adjusted. The IAC requires a certain amount of by-pass air in order to work properly. If the butterfly valve closes too tight then the IAC doesn't have enough time to react to changing idle conditions and the car will die.
 

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Discussion Starter #3
yeah right now the idle is kinda high itll stay at like 1500 rpms or so when cold then drops down to maybe 900 rpms bama tuneing guy said my idle duty cycle needed to be at 0.35 , its currently at like 0.25 ,only way i can get it to hold a 0.35 value is to lower the idle but when i did that even after a idle relearn , it wants to lung foward hard when put in gear its a auto
 

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Hell, I don't know data logs. If the car runs good then OK. What I know is that I adjusted the throttle body stop screw and it fixed my problem. If you wish to investigate further then that is up to you but I've been a member of this forum a long, long time. Adjusting the set screw has fixed a lot of problems.
 
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Discussion Starter #9
yeah i think setting the tb screw will solve the issue also ,from what i hear theres a sweet spot for them, like i said its kinda of a high idle, but in gear its a low idle, also theres a pattern to it when it does it ,maybe 3 times itll rev up and down and about third time it stalls out

---------- Post added at 07:50 PM ---------- Previous post was at 07:47 PM ----------

also the dataloggs are pretty simple to read ,i just pay attention to the values and tells me alot, had a issue not to long ago after header's installed , one of the up stream o2's was bad and the live data really helped alot! noticed one had no value at all and was like yeah that 1's shot and sure enough was!
 

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Discussion Starter #10
correct me if i wrong ,but shouldnt my tps volts be at aleast 1.00 or tad lower on the 4.6 2v? and not 1.12
 
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