Need help with Diagnosing Hard Cold Start

[Jeff Baker]

I have a 2001 F250 w/ 7.3 Powerstroke. It's also a California truck, although I live in Colorado now. About 3 months ago, I had a new cam sensor installed by the dealer. About 2 months ago I installed a Quadzilla 4 bank chip (plugs into the computer) with the Commander and a 4 inch exhaust. About 1 month ago, I experienced the 1st cold start problem I've ever had.

When the water temp is below about 45 degrees, it won't fire. We've installed new batteries and a new glow plug module to no avail. Mechanic has checked the glow plug relay and the glow plugs and he says all are fine. If I plug it in, it starts right up. Problem is, I cannot plug it in at work, or when I'm on the road.

I removed the chip, but that did not help either.

All roads lead to the glow plug system, but cannot find anything wrong with it. Ideas? I'm about $550 into this so far with no answers.

[mschn99]

if fuel pressure is good....glow plug system is good.......then there are only two other reasons why it wouldnt start in a "real world" situation. There are all kinds of things like a biased ICP thats only biased cold and things like that that are possible....but the only good explanation that is common would be this...

Either your injector o rings are hardened and are not sealing properly cold....

Or your motor is down on compression and the rings dont seal well cold...

I would bet on...just based on my experience...its the injector o rings......But thats a "jugement call" for the tech on the newer 7.3's...there isnt a real good fool proof test for it....