Hey all I just revived my 2003 7.3L that had broken rings on cyl 8 and rebuilt the motor, gave her new 160cc stock nozzle single shots. And rebuilt the turbo with new ats and banks housings. After the rebuild she cranks for approx 4-5 seconds before starts and cackles a bit before leveling off showing 75% engine load. When driving she cannot get out of her own way at all at low rpm and at 1500+ rpm engine load goes to normal but still lacks power. and when slowing down I pop it out of gear coming to a light and she cant keep up at the low rpm and dies. Will start again but it's like the engine is de-fueling. Boost wont go over 3-5psi, I've triple checked all exsaust and CAC boots. Good leads and sensors on icp and ipr. Ebp has a good lead and cleaned tube and sensor. New throttle pos sensor. New map sensor and hose. I've been beating my head against the wall trying to pin this one down. Please help!

 

What are your IPR DC, ICP, fuel pressure (post filter) and FIPW numbers?

 

I'm not sure what FIPW is might have to explain that one to me. Icp is giving me 510 at idle and goes steadily up till 2800 psi. One time I decided to give it full throttle and I got 3000 psi briefly. Now the fuel side I'm not sure. I have an FRX on there and put on a new fuel pump and filter. All I've done is measure voltage at ipr pigtail and new ipr. Cyl contribution test came back perfect. So a good place to start would be fuel pressure post filter?

 

Also noticed my oil temp gets to 203° very quickly with normal driving, not sure if that's cause just to get anywhere engine load is around 70-90%.

 

FIPW is fuel injector pulsewidth. It shouldn't be higher than 3ms.

The fact that your HPOP is able to reach 500psi at idle and 2800psi higher up seems to indicate it is ok. Just to be sure though, what is your IPR DC when you get 500psi ICP at idle?

For the sensors you did replace, did you use Ford/Motorscraft or aftermarket parts?

 

So my pw is measured in Usec, it is 30usec which is .03ms at idle. I'm not sure how to get ipr duty cycle? Banks idash doesnt give that. I used aftermarket ipr and icp. Probably a bad choice but they both have lifetime warranty so that's a plus. I replaced the icp once already just to see...... Haha and it was free! Took the ipr out and cleaned it. How likely is it I got a bad IPR strait out of the box and is there a way to test it?

 

My only other thought would be a pcm possibly unless that ipr was bad out of the box. But whenever the truck picks back up after trying to fall out it idles very well.

 

If the ICP is ranging from 500 to 2800psi that's pretty much what it should be doing, so the IPR and ICP are working.

No codes? What do you mean by engine load?

How much fuel is in it? Get it over 1/4 tank in case the fuel pick up foot broke off.

I'm thinking fuel, seems to be a thing recently. If you have compressed air disconnect the fuel line at rear of pump, open fuel door, shot some air back to the tank. This can blow the crud off the filters for a while. Then it would be Hutch and Harpoon mod time.

 

Engine load is just a pid available on idash I'm not sure how its calculated but it seems to be spot on with how the engine is running. But ya thanks for the info I'm going to give that a shot in the morning. If it works I'll definitely be doing hutch and harpoon. Thanks for the advice I'll let you know how it worked.

 

Well I couldn't wait till morning, but I took the fuel cap off crawled under the truck and shot compressed air back to the tank on the intake side. Drove around and there is no change. So unless there is air getting in somewhere the fuel side should be ok key word "should". I feel like I've gone over the entire injection system on this thing.......... lol watch it be something simple.

 

Do you have it tuned for the single shot injectors? Do you have an EGT gauge? If so what's it reading, if not best get one quick. And how's it smoking while all this is going on?

 

Yes I have tunes from Jody at DP for the single shots. Surprisingly egts are normal. So trying to make it up a hill...(trying).... egts will hover 790 or so, did go to 1200 when I flipped to 60hp tune to see what would happen. Still the power wasn't there at all 3.5lbs boost but power is lacking so much that almost full throttle on slight grade I still have to downshift when I should be pulling away from the crowd easily. And it doesnt smoke noticeably at all until I put the 60hp tune and generous throttle. But not anywhere near the amount you would expect. That's why I keep chasing electrical. Air and fuel systems seem to be operating perfectly but something is telling them to cut back. At least that's how it appears.

 

You say air and fuel working normally but 3.5 boost doesn't sound normal. Even on a stock turbo should be about 15. Might want to open air system up and make sure there isn't a rag that got sucked in or something similar.
Also build a boost leak detector and check CAC system that way

 

I may have stated that wrong and I agree that setup should be pumping 25+ psi boost 375hp. But it's like the pcm is saying " de-fuel" for some reason. So when driving it the power is less than if I didn't have a turbo at all. The only sensors I didn't check was the cps. But if the cps was bad it would dropping like I turned the key off right? And with no codes.....? The shop that scanned it I dont think they were very thorough but did say a icp fault. So if two brand new sensors didn't fix it and the pigtail had 5 volts key on good continuity it almost had to be pcm? Or does the icp pigtail have different volt specs? Thanks

 

Since it was apart and recently back together, maybe there is an exhaust leak at the back of the turbo. It can be difficult to line up the collector to the baby's butt, and a leak there would lose a lot of drive pressure. Get a nice close up pic of that clamp, let's see if it's lined up correctly.

If the PCM was defueling you'd hit 22psi first, then it would defuel. And then return to normal a few minutes later.

X2 on the boost leak detector idea.