Greetings all,

Just got my first diesel & now I know why I got an un-believable price! Early 99 f250 7.3. First week I'm pouring white smoke-fuel into coolant. OK, I search the interwebs & figure out it's the injector sleeves. I replace them myself w/ a tap & a bunch of swearing. Did the injector o-rings too. Now the damn thing feels way underpowered. I knew of the leak so I never pushed the truck prior. I'm thinking it's a fuel issue b/c even w/ a bad turbo an engine that size should move from a standstill w/o flooring it! Got 15lbs boost sitting still but doesn't seem to boost while driving. Impeller is tight & spins freely. I hear the wastegate work when it shifts. I have to floor the accelerator just to get moving! Shimmed the regulator which helped a little. NO SMOKE at all, even during morning start up. Idles fine & starts right up. Feels like I have a 4 cylynder in there though. I swapped MAP's but it runs better unplugged than w/ the new one?! Had an IDM code so I replaced that. Ran a little better but still no power. Cruising at 60-70 is a struggle, constant downshifts. Fuel pressure at idle is 70 but haven't checked it under load. Will clean the IPR today & straight pipe the exhaust. My understanding is it could be the hpop since that controls the injectors or a failing fuel pump? Could it be as simple as the pedal position sensor, IPR or CPS? I have sacrified a puny Honda in hopes of some insight from the pros here!

 

I dunn bro but hopefully some ford guru has a tip for ya

 

I read this earlier and walked away for a bit. You have way too much broken up info and I need it laid out a bit more...

How many miles?

Any mods to the truck? Chip? Intake? Exctra?

Lifted?

You say it has 70psi fuel pressure, how did you check this?

You will never hear the wastegate on a 7.3, just not going to happen, you will hear surge, stall and such, but not the wastegate.

You should see no boost sitting still unless your powerbraking it, and stock it should be about 17psi max...

 

Yea, that was an info diarreah on my part. Except for a lift & tires (4" & 35's) it's stock. 143k miles. It does have a k&n sticker but stock filter. I thought maybe it had a chip at one point & that may be my issue. No chip now though. I read elsewhere about the wastegate but when it shifts I hear a distinct whoosh. I floor it I get slight turbo whine but nothing like my friends F250. Pedal to the floor just to get up inclines or pass traffic. Maybe the fuel read 60 but it was a shitty gauge & I checked @ the pump so I know the psi can drop under load. Checked boost at the spot where the wastegate tube connects to the front of the tubes. Just revved it to 3000rpm & got about 15psi MANIFOLD PRESSURE. Big omission on my part, I'll check boost under load tomorrow. Just don't think it's my turbo since the truck barely gets off the line w/o flooring it. Feels like it wants to boost but not enough fuel. I'm new to diesels but not auto mechanics & it feels like it's underfueled. From what I've researched I'm thinking the HPOP could be the culprit? Either way it's going to get a stealth hpop or garrett turbo depending on which is bad!

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I know I'm all over the place but I work 6 days a week, 70hrs & barely get a chance to run out to the lot & tinker w/ the truck here & there then log on the internet here & there. My apologies. I work at a garage where we are not allowed to touch our own vehicles!!! Good thing I'm the manager...

 

Did you check for Codes?
Have you checked fuel filter?
Have you thought about looking at the sending unit in the fuel tank?
If the fuel pressure is at 60 how much does it drop when you lay into it? If there is a significant drop! Trace the system from the filter back to the tank, If it is all fine. You may have done something wrong in your reinstallation of injectors. You said it was a pain and it caused some interesting vocabulary?

 

Not sure how I could mess up the injectors. Tedious but straightfoward, replaced all o-rings, cleaned connections, replaced glow plugs, used install tool for sleeves w/ loctite. Getting to the suckers was the real pain. No codes after I replaced the IDM. New fuel filter. I even drained the fresh Rotella T6 Syn. back to 15w40 in case of low oil pressure! Haven't had time to check fuel pressure while driving. All tubes are tight concerning the turbo. Will test the complete fuel system tomorrow. Just hoping someones had a similiar problem & can shop me in the right direction.

 

And as I mentioned earlier, it runs a little better w/ the MAP unplugged even after swapping it out w/ a friends. I also plugged the wastegate, unplugged the EBV & shimmed the fuel regulator all of which helped but she's still embarassingly underpowered. I have to hit the pedal about 1/2 way down before she starts moving.

 

Few things...

There is no way you got 15psi free revving the motor to 3k. Just not going to happen without a load on it.

If you have 60psi at the fuel bowl then that is not your issue, anything above 30psi and you will not feel the difference.

The "whoosh" you hear is turbo stall, which will happen when the truck shifts. The turbo stalls as the air requirements of the motor change drastically.

Check your up pipes (pictured below) and all the Inter cooler boots for leaks, you can build a test rig that hooks to the factory intake tube and pressurize the motor to 15-18psi. If you have any leaks you will know RIGHT away.



I'm assuming you have the MAP sensor plugged in, because the truck will not fuel properly without it.

 

If you work at a shop then you need to get it on a scan tool of some kind. Plug stuff back in, your making it to where its impossible to diagnose.

Once you have it on a scanner check the Duty cycle and High Pressure Oil Pressure when driving.

When Driving you should see about 1500-1900 when cruising. At WOT you should see no less then 2300psi at about 50% duty cycle.

 

First off I appreciate your input, you seem to know your stuff from all the threads I've been searching. The boost was never checked. My mechanic checked positive manifold pressure & I misunderstood him. I'll check it tomorrow. I checked fuel pressure at the pump since I couldn't find a schrader valve & that was the easiest spot. I know I need to drive it & see if the pressure falls off. My issue w/ it being a turbo problem is that from a stop, when the turbo is not normally fully spooled, I have to hit the pedal about 1/2 way before she starts moving. I would think she should still move w/ that big engine until the turbo kicks in. At cruising speeds she constantly downshifts just to stay above 60. The power is lackluster all the time, hence my fuel issue diagnosis. Want to clear that hurdle before I get into the HPOP which I believe controls fueling too?