my truck stalls when i let off the gas... This is intermitten. I have replaced the fuel pump, iac valve, tps, cleaned the throttle body, checked the battery and still my truck stalls if the gas pedal is not being pushed. Could this be the fuel pump relay?

 

Probably not. Getting any codes?

Usually, that is a product of a dirty TB, bad IAC... or, failing O2 sensor..... Fixed the plenum yet?

 

Replaced everything but the plenum... where and what is that?

 

have a read of the stickied end all be all plenum thread at the top of this forum.

 

+1... read the plenum sticky. But just out of curiosity , what brand IAC did you use , and did you have the negative battery cable disconnected when replacing it?

 

Yes the truck has actually been in the shop since that part was replaced. I am not sure of the particular brand of IAC that was replaced.The shop replaced the TPS and it is still doing its random stall... I am wondering if the fuel pump I replaced a few months ago has gone bad? I got it from O'Reilly's and it is still covered under warranty. If i only replaced the fuel pump and not the fuel pump relay at that time- would that cause this to happen again?

 

SO, a shop is doing the work? Not you. Good luck telling them what to do and how to do the troubleshooting.

 

Actually i only had it in the shop to get the TPS replaced. They showed the TPS code and fuel pump relay codes so I just had them replace the TPS since they believed that was the problem. Everything else has been done at home... I think I will go with my gut and get a new fuel pump relay (never replaced that)- today and change out the fuel pump i replaced once- and put a new one on and cross my fingers it works for good after this...

 

You can switch the fuel pump relay with another working one that's in the pdc. but its not likely that's the problem considering the symptoms you gave. Save yourself a few hours of work and test fuel pressure before replacing the pump. If you end up needing a new pump, Denso or Delphi pumps are what you want to get.

 

fuel pressure is strong then weak. this is off and on when i test it..i will replace the fuel pump again this evening and hope all is fixed for good! thank you everyone for ALL suggestions!! I will let you know what happens after this!!