Ok so I have been trying to figure out what the problem is with my truck for a long time. It has no power at all without the POS diablo chip i bought the truck with, but with it in there truck runs like a strong stock truck should. It almost feels like the truck is cold without the chip in it ( low power). I have ruled out alot of probable causes. I have put it on a snap on scanner and there are no codes. I really thought i had a pcm issue but it definatly is not. I have tried swapping 3 pcm and idms out of good running trucks. Injectors, injector o-rings are good. Fuel pressure is good 65psi, the scanner showed 2600 psi at wot for HPOP, ipr good, map sensor good etc. I have put over 10k on the truck since i bought it and it runs great motor is def good. I feel like there is some sensor or an input or output to the pcm that is not working right. Maybe EOT sensor? Idk. I am open to any suggestions that could cause the engine to have very low power. Does anyone have a link to the input and output operations of the pcm and what the specs are suppose to be so I can put it on the scanner and make sure all my functions are at the right level ? Thanks in advance for any info or ideas to what this could be.

 

Unplug the electrical connector on the map sensor & see what you get ...

 

Yea I did but I didn't notice any difference

 

i was just going to make a thread on this you creep lol

ok heres what we have

NO ***** with STOCK pcm and idm from a well known working healthy truck.
showes 47~%DC and 25-2600psi at WOT, so its not oil

unpluged and swapped over every possible sensor with my truck and put the sensors and pcm/idm in my truck, mine runs just peachy.

put in a good working custom chip for the truck and it runs just the same as stock just revs a smidge faster and then falls on its face again, on ANY SETTING. the chip works in my truck! Matts chip in his truck tests out to 48%DC and 2650-90 psi. so his pump is strong

So what does the DIABLO chip overide that Matts chip and Stock pcm calibration do not?!?!

what other sensors are there to do. and IPR has been rebuilt, clean as a whistle, strong fuel pressure. thing just flatout rips with a DIABLO predator chip in the truck, 25psi of boost.

now before you say try the map,icp,Eot,pcm,idm,fuel bowl blah blah it has either been swapped out, unplugged or cleaned and made sure it works, ZERO pcm codes.

so litterally what else is there to test out?

 

can any of this be transmission related? were trying my manual pcm in this tomorro, its the ONLY thing we have not tried so figured we would give it a wirle

 

I have NO idea, I just know these trucks are pigs when they are left stock. Mine was

 

What are boost pressures?

 

The manual PCM will more then likley not work in the auto truck. It probaly doesn't have trans info for shift points.

 

tried the manual pcm, it will drive but we didnt bother, from idol foot on break and foot to the floor on pedal it will not rev past 1300ish rpm becuase it just cant do it. its not tthat the truck is a stock dog, its litterally a flat out not fueling enough dog.
i tried his diablo in my truck and my truck still has a huge sack to it!

shaun i think we need to get a video to show these guys how nutless it really is with out the chip, its amazing.

 

Yea Steve I have some videos on my YouTube of me driving it without the chip. And as for the boost pressures when the diablo chip is in it I can hit 24-25 psi. Without the chip it will max out at like 10-15 after I have it at wot for an hour lol.

I feel like we are overlooking something but I dnt know what. Need your help on this one guys I am getting really depressed over this one.

 

Is your fuel pressure measurement at idle or under load?

 

The reading was at idle. And the fuel pump is new because the old one was leaking.

 

did you try blowing in the map line to see if it was clogged yet, i feel like that it litterally the only thing we havent done yet..

 

Not yet Steve crazy day at work out to eat right now I'm going to do it tmro. Cross your fingers lol

 

Gonna need to test fuel pressure under load. Could be dropping too low under load