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Compression test good - going under the knife - DTC help

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Old 10-05-2017, 04:34 PM
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Compression test good - going under the knife - DTC help

My 94.5 has 289k miles on it. I've had it for 2 years and have put 43k miles on her. Some friends of mine who know PSDs have mentioned that it has a misfire and it feels a little down on power. The injectors are original as far as I know. I've been wanting to do injectors and a tune since I've owned it and now is it's time to do it. Parts will be here next week from DP Tuner (F6 chip) and Full Force Diesel (180cc stage 1s, stock nozzles). All cylinders were around 300-320psi when the truck had been running and then it sat for about 3 hrs on my block heater so the engine was pretty warm when I ran the test. I'm at 7400 ft so at sea level this corrects to ~400psi. I'm incredibly happy, pleased, and relieved with this result.

1 year ago I did the following work, all new OEM Motorcraft parts:
Injector o-rings
ZD-11 glowplugs
2 VC gaskets
4 UVCH harnesses
Oil temp sensor

This solved the cold start issues I was having. I also replaced the harness connector that goes into the VC female harness on cylinders 5 and 7 since there were a few burnt wires and the connector clip had broken.

I have an Aeroforce scangauge and when I run the cylinder contribution tests and injector buzz tests I get the following codes:

CCT:
P0263 Cylinder 1 Contribution/Balance Fault
P0266 Cylinder 2 Contribution/Balance Fault
P0272 Cylinder 4 Contribution/Balance Fault
P0278 Cylinder 6 Contribution/Balance Fault

Buzz test:
P1265 High to Low Side Short – Cylinder 5
P1298 IDM Failure

The P1298 code seems odd. If the IDM was bad wouldn't the truck not run?

I've had a bad fuel leak for a while (sensor on bottom of bowl is leaking, I think the housing is cracked) and I suspect my fuel pump is tired and leaking too. I'm usually around 50psi of fuel pressure at idle. I'm replacing/rebuilding the fuel bowl (new casting) and fuel pump this weekend. Then putting the injectors and tuner on Thurs/Fri of next week.

I'm hoping that most of the CCT failures are related to the injectors themselves and not something in the IDM and/or IDM harness. While I'm monkeying around with it this weekend I'll check the connections as outlined here:

» TB 103: 1994-03 Ford 7.3L IDM Replacement & Diagnostics

Sorry for the rambling. I really excited to get it running on all 8 again and with the new sticks and tune it should be a completely different truck.

If anyone has any input on the DTCs or troubleshooting that would be great!
 
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Old 10-05-2017, 09:32 PM
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I'm not much help but why go to the trouble rebuilding the fuel bowl? With the bigger injectors maybe you should go to electric fuel. I would guess a few of the codes will go away with new injectors. Also, I'm with you about the IDM failure, that's weird. Once I was on the side of the road with a CPS code and a new CPS didn't get it running. Replaced IDM and the way I went.
 
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Old 10-06-2017, 12:12 AM
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Originally Posted by oldbird1965
I'm not much help but why go to the trouble rebuilding the fuel bowl? With the bigger injectors maybe you should go to electric fuel. I would guess a few of the codes will go away with new injectors. Also, I'm with you about the IDM failure, that's weird. Once I was on the side of the road with a CPS code and a new CPS didn't get it running. Replaced IDM and the way I went.
I'm planning to eventually do a turbo, IC, HPOP, e-fuel and all those goodies later on down the road. That is one of the reasons I opted to go with the 180s over 160s. When I do the big stuff later on I can get the 180s re-nozzled for ~$500. Knowing my future plans, both Jodi from DP and Clay from Riff Raff recommended I go with the 180s over 160s.

I may try and pick up an IDM on ebay to have laying around to help me troubleshoot it. Wouldn't hurt to have an extra. I replaced the CPS last fall with a new OEM one and bought a second and have it in the truck at all times just in case.

For now time and budget only allows for the sticks and tune. I've had all the parts to replace the fuel pump and fuel bowl for a while. I picked up a used bowl housing on ebay. Mine is cracked at the restriction sensor on the bottom. Last summer I rebuilt it and made the fuel leak worse.

I don't post here much but I lurk and search a ton and the info you guys share in here is invaluable! I'm a novice-intermediate mechanic at best but this place rocks and I've learned a ton.
 
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