Will not start cold

[ChrisB]

92 GMC 2500 6.5 L. Injector pump, lift pump and sending unit were replaced at dealership, truck worked fine, but the weather was warm. Blew a head gasket and got that replaced after that the truck had difficulty starting in the cold even when plugged in, when it's really cold it will not start at all without a boost, it seems that the engine warms up enough through cranking it over that it eventually starts. All glow plugs were replaced when the head gasket was done, they are AC 60G's. The truck is at the dealer now, the injectors all tested bad(leak down) so they were replaced, no difference, the dealer bypassed the glow plug con troller to allow the plugs to heat up longer and the truck started, but the controller tests fine according to them. They are trying to say that the wrong head gasket was installed(nmot done by them) and this is causing the problem. When warm it fires right up no problem. Any suggestions.

[DmaxMaverick]

!!!!!

Don't go pulling heads and such before you check the glow plugs again. Those 60G's require twice the time to come to heat than previous 9G's or 11G's. You proved that when the controller was bypassed and more glow time was allowed. The controller may be working perfectly, but only for 9's or 11's.

You can either modify the controller to add time, or add a manual control (dash mounted button, etc.) that would allow you to manually extend the glow time.

Try bypassing the controller on a real cold morning and glow longer. If it starts OK, then you've found your problem.

Good luck!

[Wheat Whacker]

I agree with Dmax don't go pulling heads I had the same exact problem with mine after a head gasket replacement and the problem was simple the terminals on the wires to the glow plugs were fine until they removed them when they pulled the heads but after they put it back together the terminals were not making good contact with the glow plug terminals. This of course caused tremendously hard starts when cold but it would pop right off when warm. Long story short the terminals on the wires and glow plugs were clean and viola the problem was fixed. Of course this took me about 2 weeks to figure out and it just had to be the coldest weather of the year.

Just a thought. It fixed mine.