i have big trouble starting my 88 7.3 when its cold out the past 2 days its been below 20 degreese and it wouldn't start at all i just shot it with a blast of start fluid and it started like it is warmed up what could be my problem

thanks for the help guys

 

Glow plugs are probably toast.....what brand are installed. Check the ohms on them..

If you have 2 or more bad GPs, the controller may not cycle at all.

Two problems that occur with the solid state ( 1987 to 1994 IDI engines ) GP systems. If a GP burns out ( circuit resistance goes up ), the controller cycles the GPs at a faster rate which doesn't let them get to max operating temp. If 2 or more GPs fail, the controller may not cycle the GPs at all ( very rapid or no clicking heard ). When you check the GPs, use an ohmmeter. A high resistance ( not necessarily burned out ) GP can cause circuit resistance to go up and the controller will then cycle the GPs too fast. You probably will not find this problem with a test light. Resistance spec for GPs = .5 to 1 ohm cold. Second problem. A poor controller ground ( black wire attached to valve cover stud ) will cause the controller to leave the GPs on longer, often damaging or failing them. If you are having mulitple GP failures, I would check closely the controller ground. Now the confusing part. Bad ground --> longer GP on time ( slower cycling ). Burned out GPs --> faster cycling If you have both situations, it may appear that the controller is cycling the GPs at the proper rate. Bad ground slows it up while the burned GPs speed it up ---> normal cycling. The system acts/sounds like it's working normally, but you have a hard starting concern.
DieselDon

Glow plug torque is 12 ft lbs, I always use antisieze on the threads.

 

PLC7.3 hit it right on the head. I had a similar problem on a truck I was working on, all the GPs checked out with a test light but it had short erratic cycle time, I changed the controller and it did the same thing. After rechecking the GPs I noticed a lot of rust on the spade (electrical contact)of most of the GPs, I cleaned all the spades with emery cloth and that took care of the problem.

 

If the GPs check out, then corrosion on the GP and/or wire ends must be checked. Possibly burned out wire too, use a test light between tip of gp and the wire end, turn key on and watch for power.