SGT. Diesel Posted December 14, 2005 Share Posted December 14, 2005 We have been working on a 2000 F-350 7.3L for a while now. When we drive it and after it gets warm, one at a time it appears that the cylinders are cutting out. Eventually the engine will shut down. At idle the engine will run fine. We have done the anti-aeration test with the WDS and it failed. We changed the oil and that it didn't help. We found on another site that the sometimes the oil pick-up tubes will develop cracks. We added a couple of quarts of oil and raised the back of the vehicle and it did not stop running. So...we replaced the pick-up tube and just for the hell of we put in a new oil pump. We also switched out the injection control module and that didn't improve anything. Anybody have any ideas of where to go next? /forums/images/%%GRAEMLIN_URL%%/hammer2.gif Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted December 14, 2005 Share Posted December 14, 2005 Here's a silly question, what is your fuel pressure doing when the engine starts to cut out? When fuel pressure drops, ICP goes up to compensate therefore you might not actually be failing the oil aeration test. I see these kind of readings when fuel gels up... the truck will start but as the pick-up screen clogs, fuel pressure drops and you can see the ICP coming up at the same time until it can no longer compensate. The engine then stalls. Just a thought. Quote Link to comment Share on other sites More sharing options...
SGT. Diesel Posted December 15, 2005 Author Share Posted December 15, 2005 When the vehicle first came in, thinking that this was a fuel problem we changed the pump. Today using the WDS we looked at the ICP PID (I'm catching on to the Ford lingo) we couldn't notice anything abnormal before the engine would start to stumble. We looked into checking the fuel pressure at the heads but we don't have the right fittings for our psi gague so getting a fuel pressure reading in not possible at the moment, unless the WDS can do it and we just don't know how. Quote Link to comment Share on other sites More sharing options...
m-mathus Posted December 15, 2005 Share Posted December 15, 2005 an easier way to check fuel pressure than checking at the heads is to take an old fuel filter cover and tap a fitting into it. i used a schrader fitting from a gas fuel rail so my gas fuel guage will hook up to it. it takes just a few minutes to hook up and you'll also be right there to inspect the fuel and filters. Quote Link to comment Share on other sites More sharing options...
SGT. Diesel Posted December 17, 2005 Author Share Posted December 17, 2005 I like the idea for the fuel psi gague, but management dosen't. We don't have any extra but we can order some. Since we can't get an fuel pressure reading, we wanted to eliminate the HPOP. We brought in a F-350 of the same year, removed the HPOP and put it in the one we are having trouble with.(Don't know if that was a good idea or not but we're grasping at straws--Explosive Ordinance Disposal and some C-4 will be next)Once it was installed the engine wouldn't start. It would turn over great, fuel would shoot out the bleeder behind the filter houseing when cracked, but it just would not start. Oil level is good in the reservoir. We took the HPOP out and put it back in the original engine and it runs like a champ. Today we are going to put the original HPOP back in the original engine and see what happens. I believe this would indicate that there is not a problem with the HPOP. Maybe a restriction somewhere else? Quote Link to comment Share on other sites More sharing options...
SGT. Diesel Posted December 17, 2005 Author Share Posted December 17, 2005 Thought we had it today... When management wasn't looken we tapped a schrader valve into the fuel reservoir cap. Pump was putting out 50-60psi with the engine running. As the RPMs were brought up the needle went down to zero, emptied the resrvoir. We pulled the fuel sending unit, discovered that the plastic holding the screen was rotten and all broken up. There was also a tube of some sort disconneted. Now this is not your typical F-350. This is one of those contractor crations where the frame has been shortened and weight added to the back for towing bombs and rockets. All of this is to meet certain Air Force requirements. I doubt this sending unit and fuel tank are Ford parts. We rigged the sending unit back together, tested the fuel pressure which stayed between 50-60psi. My fellow mechanic went for a test drive and the darn thing cut out on him. He is just slightly upset. /forums/images/%%GRAEMLIN_URL%%/smhair.gif I mentioned in the previous post that when the HPOP was swapped out this engine wouldn't run. When that original was put back in, it started up just like normal. Quote Link to comment Share on other sites More sharing options...
SGT. Diesel Posted January 2, 2006 Author Share Posted January 2, 2006 We finally figured this beast out. /forums/images/%%GRAEMLIN_URL%%/thumbup.gif Quote Link to comment Share on other sites More sharing options...
Torqued_Up Posted January 16, 2006 Share Posted January 16, 2006 This reminds me that a few years ago there was a problem with the gas engine pick-up screens being too fine and they were plugging up causing low power concerns. You problem sounds just like what happens when diesel fuel gells up and clogs the filter and pick up in the tank. All we can do is push it in the shop and let it warm up overnight. So far, not one victim of fuel gelling yet this year! Could all of these 1st time diesel owners fianlly learned their lesson? /forums/images/%%GRAEMLIN_URL%%/rofl.gif Quote Link to comment Share on other sites More sharing options...
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