I have a 95 7.3 slop truck that wont start in the cold, more like cool weather. thought it was glow plugs changed them and harnesses. have power at glow plugs still nothing. Checked fuel pressure and it was 50 so changed fuel pump. No luck. Could I be looking at needing injectors? What this fuel heater I see people talking about on this site? Thanks

 

It could be injectors, are you billowing white smoke? Do you smoke after warm up? Have you checked voltage in/out of your IDM? Do you know if your oil pressure regulator and ICP are good? How does it run once it starts? How many miles?

 

slop truck? block heater may help...im in hawaii so its not cold , but moistier that give me trouble, my truck sat for a year out in the weather and im working on getting her running...good luck to us both, aloha howed the fuel pump change go, you do it yourself? i think that you have to pull the turbo, sounds like a pain...thanks

 

It blows white smoke when it first starts and goes away after a min or two. I have not checked voltage on Idm, where is that located. also dont know about the oil pressure regulator. It runs great after you get it going the first time and restarts great rest of the day. 150k on truck but it came from the oil field up at prudhoe bay and they run all winter long so lots of idle time! bettyford, I spelled slope wrong. North slope is prudhoe bay oil field. And the fuel pump was pretty easy. I did not have to take the turbo off but it would have made it easier to get the big banjo bolt off the back of the fuel pump. Just pull off the intake runners from turbo and you can get to every think just fine.

 

Sounds like a glow plug problem, maybe injector o-rings, but I this is a stereotypical glow plug symptom. Try waiting another 30 seconds after the WTS light goes out before starting, this will give the glow plugs a chance to fully heat up. If this helps, I would seriously consider replacing the GPR, as it may not be able to deliver enough current to really heat the plugs properly. Also, check your blowby. Warm the engine and then take off the oil cap, flip it over and set it on the hole. If it dances, you may have low compression in a cylinder.

 

I will go try that right now but I have tried cycling the key three to four times to ket the glow plugs get hot, and i did have power to all the plugs when the valve covers wherr off. If I remember right they were not all the same and not 12 volt some where under ten volts! Thabks for the help

 

Here's a good writeup on testing the GP system. If it passes this, then I would check for blowby then replace injector o-rings. I would suspect the low voltage plugs.

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Low, uneven voltage at the plugs suggest extra resistance in the harness to the plugs.

 

Glow plug relay . Had the same problem last winter . Did the same thing you did . Changed the relay and cured the problem . Hint just because there is power to the glow plugs dose not mean the relay is working .

 

What and where is the IDM?

 

The IDM is the Injector Driver Module. Mine was located behind the battery under the degas bottle, ,but my 7.3 came out of an E350 bus. It drives the injectors and feeds them high voltage. IF you're blowing white smoke and it runs well once it starts I doubt the IDM is involved unless your batteries are weak and your voltage is seriously low during cranking. Did you check the GP system?