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2001 F-250 w/7.3 Cold Start
I have been "fighting" this problem for the 2nd winter now.
My 7.3 will not start when it is cold. White smoke out of exhaust while cranking. When warm, or when the block heater is plugged in, it starts perfectly.
The truck is a California truck and has a Glow Plug Module. It also has what appears to be a Glow Plug Relay (I thought that the modlue was in place of the relay). Truck has new batteries. 2 different mechanics have checked it out, and both say the glow plug system is working properly testing with an ohm meter. The Glow Plug Module was replaced with no success. The 2nd mechanic claims to have pulled the left valve cover and one of the glow plugs (although I don't know which one). Claims that he "bench tested" this glow plug and it performed just as a new one. He also indicated that oil and fuel systems (to include pressure) is perfect. He then claimed that he concluded that I had low compression, and the engine needs rings. He did mention that had never seen a 7.3 so clean at the turbo with this many mikes (105K). He said it must have been hot, as he was pretty sure it did not get dirt in it.
I have owned the truck since it was new. While I only put an EGT gauge on the summer before the problem started, it has never been over 1,050 degrees (for an instant) or over 800 - 850 degress for any duration in pulling (I pull a race trailer that weighs maybe 7,500#s on occasion). The first 5 years I owned it, I did not have an EGT guage, but never pushed it hard. I also put a Quadzilla F-Chip in it with a 4" exhaust at the same time I installed the EGT guage. I have been extremely mindful of the EGTs since putting the chip in.
I have a hard time believing that the rings are bad. The truck uses no oil and has not had any reduction in power or fuel mileage. Furthermore, if the water temp is above 46 degrees, it will start. Pretty specific about the water temp to get it to start.
I also do not see any movement in the voltage guage in the dash when I cycle the glow plugs, although the light and chime do work. Neither mechanic mentioned whether they checked the system using the OBD-II diagnostics.
I've heard one or more bad glow plugs can cause this problem. Could the PCM be the problem? What of the Glow Plug Timer I now read about? How do you check this?