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I have a 95 7.3 like 6 months ago replaced cps ran good one day died out. replaced fuel pump started running ran 30 mins at idle then it acted like it ran out of gas. Replaced ipr valve and starter as well. Cranking white smoke acts like it wants to start... i replaced fuel bowl harness and got some other un needed draws on the batteries, finally got it to restart again ran and drove about 30-40 mins and again acts like its running out out gas. Any ideas could it be fuel pressure from the spring being worn in the fuel bowl could it be a problem in the tank? If it where the hpop i doubt it would run in the first place..
 

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What's the fuel pressure when cranking? Have you tried switching tanks? What level are the tanks at? Are there any mods to the truck like a chip? Cheers!
 

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I’m going to check the fuel pressure today. Both tanks are at half, ill try switching its been on the front tank. Its just crazy cause it was running great went around the block reving like a champ ran for about 35 mins then cut out.
 

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Does it slobber and sputter or just flat quit dead like you dumped the clutch? Mine is acting up similar, embarrassing to say but it happened last February. Running fine in the morning, sat in a parking lot for 4 hours, fired right up as normal, idles fine for 2-3 minutes. I pulled out, then I’m going to call it a cough as I pulled onto the highway, felt about like a backfire on a carbureted gasser when you push it a little hard when the choke is still on. Was fine for 100 miles, started doing it worse and worse. Napa was open and had a cps in stock, no change. New dealer Motorcraft cps, still no change. It’s basically all OE, 165,000 miles, and had a damp valley, I was thinking air. So parts got ordered, thrown in the front seat, “will get to it”,,, and, well, just got to it. New pump, new rubber lines, cleaned resealed bowl and fpr, cleaned and checked bowl harness wiring and ipr, and still the same symptoms.

Big thing that’s strange to me is that it’s a pretty violent miss - when it cuts out driving, it’s a hard buck, feels like a backfire. Another site said it sounded like a high-pressure oil leak, probably injector o rings, going to try that next.

Any ideas on how to pinpoint which injector it might be? Can you run these with the valve covers off and see anything?
 

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Another site said it sounded like a high-pressure oil leak, probably injector o rings, going to try that next.


Don't do that - yet. If you have an injector o-ring leak, the fuel in the fuel bowl will be brown due to motor oil mixing with the fuel. No brown color = probably no leak.


Injector o-rings are under considerable hydraulic pressure - I would think they are either good or bad - no in-between.


Reading the codes would be a best first step towards diagnosis.


Check the tin nut on the IPR magnet.



Build an incandescent test light that will reach your dash. Connect it to the downstream side of fuse 22 under the hood. The objective is to see if you can correlate the engine hiccup with an interruption of electrical power.





Any ideas on how to pinpoint which injector it might be? Can you run these with the valve covers off and see anything?


Again, read the codes. An injector o-ring leak should cause a higher than normal IPR duty cycle.



Can't tell much with the vc's off.



If your injector were leaking enough to no-start the engine, there is a test you can run that will narrow down which bank the bad injector is in. The test involves forcing the engine to run on only one bank at a time. If you ran that test while monitoring the duty cycle, you might be able to determine which bank your leaky o-ring was in.



Intermittent problems are difficult to locate - as you well know. Think it thru - use your test light, and think outside the box.
 

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I’m going to check the fuel pressure today. Both tanks are at half, ill try switching its been on the front tank. Its just crazy cause it was running great went around the block reving like a champ ran for about 35 mins then cut out.



ya...what Patrick says :)
 

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That makes sense, it should be pushing oil into the fuel side - I will rig a light, that’s a plan, and should have an adapter by next week (slammed mine in a drawer). This particular one is a 95, and hasn’t been flashed - EVER - not sure torquePro will read it. Will Forscan?
 

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That makes sense, it should be pushing oil into the fuel side - I will rig a light, that’s a plan, and should have an adapter by next week (slammed mine in a drawer). This particular one is a 95, and hasn’t been flashed - EVER - not sure torquePro will read it. Will Forscan?

I use a small running light like you would find on a trailer - only because I had an extra laying around :)



I can't answer your scanner questions - sorry.
 
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