2002 excursion 7.3 low ICP.
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Joined: Mar 2006
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Okay, well then the next thing I would do is make sure the pcm ground signal is getting to the IPR. I use a test light with the wire end clipped to +12v. Unplug the IPR and touch the end of the light to the tan wire (pcm pulsed ground). The light will be dull when key is off. Turn key to run and also to start. The light will brighten for periods as the pcm supplies a stronger ground. This proves that the ground signal from pcm is present. The 12 volt going to the ipr red wire is not pcm controlled and is present all times key is in run or start, so if there is 12v at red wire, and the ground signal from tan wire, the circuit should be good.
Even if this test good, there is still the possibility that the connector pins from the harness are not making good contact to the ipr pins.
Even if this test good, there is still the possibility that the connector pins from the harness are not making good contact to the ipr pins.
Last edited by erikkloss; Feb 8, 2017 at 02:10 PM. Reason: spelling
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Tuned
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Ok so I trailered the Excursion home and started troubleshooting today. I started with pressuring up the drivers side oil rail with air and can't hear any leaks. I then went to the passenger side and tried it there and air is gushing out the oil deflector on #5 and #7. I'm not talking a little air but full blast coming out both deflectors. I am assuming the poppets stuck on these two injectors but it's hard to believe as I wasn't having any starting issues prior to the cup replacement. Any other ideas or am I looking at new injectors. There is already one reman injector in the engine. We only bought the rig about a year ago so I don't know the history of the rig but there is about 145000 on the odometer.
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Tuned
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Has anyone had luck freeing up a stuck poppet valve? I plan on swapping spots with the other two injectors on this bank to make sure I don't have another issue in the head but can't think of what could be wrong other than the injector poppet being stuck.
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Tuned
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I'm not sure but the engine started great both hot and cold and ran just fine with no issues prior to the cup work. I don't know if they were doing this before but I don't know how they could have been. If they were doing this before wouldn't I have had starting issues then?
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Tuned
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I pulled the two injectors that were dumping air out of the deflectors. I pulled the poppets out of them, didn't find anything obvious but after cleaning and reinstalling them they held air pressure without any bypassing at all. I reassembled everything and now have 2500+ PSI of ICP and it will fire but not stay running. If I keep on the starter it will keep firing but dies as soon as I let off the starter. I crawled under the truck and felt the manifolds and am not getting any warmth out of the passenger side at all, which is the side with the two injectors that had issues. Any other ideas of what to check or where to go next?
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Tuned
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I have attempted at least 10 extended cranks so I'm fairly certain all the air is out of the fuel system, but tomorrow I plan to unplug both UVCH and crank on it some more to try and work all the air out of it. I also will see if it will fire at all with just the passenger side UVCH hooked up. Any other suggestions?
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Tuned
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So I couldn't get the Excursion to fire with just the passenger side UVCH hooked up so I tried a buzz test again and had a short to ground or battery code on bank one. Pulled the valve cover again and I had smashed the injector - wire to number 5 and 7 when I installed it. Soldered the wire back together and reassembled. It fired up and I took it for about 20 miles up and down a 6% grade to work all the air out of it. I checked codes when I got home and have a P1273 cylinder 3 high to low side open code. Excursion has a terrible vibration when it shifts into 4th while under acceleration so I am hoping this is attributed to the code that I have. Also more of a vibration than I remember at an idle but can't really hear a big miss while idling or under power. So I still have some work to do but am gaining on it.
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Tuned
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I put new UVCH on both sides when I did the cup job. However they were Dorman harnesses and now I am questioning that decision to not go with factory parts. I may replace the passenger side one again since I smashed that one wire while installing. What is weird is after I soldered the wire on the UVCH I performed several buzz tests and they all passed with no codes, only after driving it did the code come up and wouldn't pass a buzz test. I also never got a check engine light.
Hotshot
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From: Puget Sound
...I may replace the passenger side one again since I smashed that one wire while installing. What is weird is after I soldered the wire on the UVCH I performed several buzz tests and they all passed with no codes, only after driving it did the code come up and wouldn't pass a buzz test. I also never got a check engine light.
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Tuned
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Ohmed out injector wiring and was getting close to 3 ohms on all passenger injectors. Pulled solenoid off #3 and found the armature screw loose. Tightened up and swapped coil with #1 to see if issue followed. Performed many buzz tests and all passed. Reassembled and test drove. No more vibration in 4th so it was the miss that was causing that. I did a cylinder contribution test through my DP Infinity tuner and it did say Cyl#3 failed. Since I am so good at getting the passenger valve cover off I might swap that injector to another spot and see what happens. I also built a boost leak detector because even on an 80 HP tune and WOT runs up a 6% grade I can't get past 16 psi of boost.
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