1994.5 - 1997 7.3L Power Stroke Diesel  

Intermittent power loss and random hard starting need help!!

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Old 06-08-2019, 03:38 AM
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Intermittent power loss and random hard starting need help!!

Okay just gonna get straight to the details here my truck is a 96 f250 extended cab long bed. Automatic 4x4 truck has 2005 axles with 35in tires 3:73 gears ( I know not the best gearing combination) but for my uses it’s always worked out decently.
Has swamps 150 injectors efuel with walbro pump and exhaust intake and rebuilt stock turbo with billet wheel. Uppipes aren’t leaking nor are the intake plenums not running a intercooler yet. Running hydra with canned tunes i do have gauges egt boost and trans. I’ve always paid very close to egts just back out when pulling trailer but lately I’ve had egt issues even when I’m not pulling a trailer. Along with periodic hard starts has almost new battery’s and ends to. Hot or cold doesn’t really matter but strange thing is though that sometimes on a long drive it’s like it picks up power. Will run decent and doesn’t have near the egt issues then little later it’s gone. Ae does show that my max hpop numbers are 2700 but that’s what it’s been for long time. Honestly haven’t checked blow by lately but it wasn’t bad about 1400 miles ago and really hasn’t used any oil in that time. Sorry guys for long post just trying to get as many details as possible for you guys. I’m thinking it’s maybe time for a compression check also it’s been high 80s and 90s lately.
 
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Old 06-10-2019, 01:58 PM
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if you don't have a spare CPS, get a new one in there
What is fuel pressure when this happens?
Does it run rough when it happens or after starting?
 
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Old 06-10-2019, 09:08 PM
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Haven’t tried the cps yet will try as soon as I get home and I’ll verify fuel pressure as well.
 
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Old 06-10-2019, 10:02 PM
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Also it never really runs ruff persay just loses power and runs high egts.
 
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Old 06-11-2019, 03:09 PM
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Low fuel pressure will make high EGTs and low power too

I use a long grease gun hose and a gauge taped to windshield and do a 3rd gear WOT run.
 
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Old 06-11-2019, 10:21 PM
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Yep just got back in town figured I’d verify fuel pressure going to swap starter with known good one and re clean all my battery terminals. Along with was considering checking lpop oil pressure. What do you guys think fuel filters have about 2500 miles on them. Running a wix pre filter and cat post and a beans sump. I’ll run tests and let you guys know.
 
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Old 06-11-2019, 11:00 PM
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Fuel filters should be fine, but you can check them and see. Anytime I have had low power and high EGTs, it is always boost related. I don't see how lack of fuel makes high EGTs when fuel is what makes EGTs in the first place. Lack of boost sure will though.
 
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Old 06-12-2019, 02:01 PM
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I was considering running a boost leak test again but to be honest it doesn’t act like that’s the issue because it has no problem building or holding boost. Everything time it has had a boost issue before it just straight up won’t hardly build boost. But it’s not something I’m leaving off th table but I’m also wondering if maybe the low hpop numbers are contributing to high egts.
 
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Old 06-12-2019, 02:19 PM
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Thumbs up

I would think a weak HPOP would make higher EGTs, the fuel is not able to atomize as well. It will at least be smokier.

Mine will not even hold 2500psi on a stock tune. The hot street tune dips around 1400psi last I looked.
 
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Old 06-12-2019, 03:22 PM
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Well fixed hard starting issue starter was bad. Checked fuel pressure it stays right at 72 70 under hard pull. Do you think verifying lpop oil pressure would be a bad idea. Still has the random high egt and power loss deal did it while verifying fuel pressure.
 
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Old 06-12-2019, 03:29 PM
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Did you upgrade to the SD style or the Denso?
 
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Old 06-12-2019, 03:29 PM
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Another thing I’ve noticed I just thought to mention is that if u simply get on it really hard it will fall on its face. But if you slowly get into it it’ll pull a lot harder atleast according to the butt dino.
 
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Old 06-12-2019, 09:03 PM
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Any chance a rag is in the intake trac? Sound very familiar like this one guy in the 7.3 superduty forums had a rag in the intercooler you might have one pre intake or at the heads just a thought.
 
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Old 06-12-2019, 11:50 PM
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Would like to do a Denso but just not in budget at moment had a fairly new spare that came off one of my parts trucks. Fires up insanely quick now compared to before. Going to pull intake off tomorrow check for boost leaks and abstructions. And possibly if I have time I’d like to run lpop oil pressure test. I’ll let you guys know the results on those.
 
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Old 06-13-2019, 11:53 AM
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Have you disconnected the ebv and wired it open? I read all the post and I do not see this mentioned .
 


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