won't start, no "clicks"

[proturf]

I have had my '90 7.3L for a couple of months. Been very happy. But noticed that it has been starting a little bit harder the last couple of weeks. Then, last night it would not start at all..... after the "wait to start" light goes off, it no longer "clicks". Can you tell this diesel-newbie where to start.... relay? controller?

Not even sure where to find these items in the engine compartment but I will go out and get me a repair manual.

[bigbigtom]

i just reacently had a similar problem with mine it turned out to be bad glow plugs i checked resistance across the old plugs (autolites) and got an average of 175-250 ohms (there supposed to be 2 ohms) so i went to oriely auto parts and ordered motocraft z-d9 (the only way to go, plus there cheaper than autolites) just be carfull pulling the old ones out theres quite a few horror stories on this forum about broken of plug tips falling down in the cylinder. i didnt have any problems though (thank god) good luck to you

[cdnsarguy]

Posted info.......

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

[Dieselnutt]

I have a 94 F350 crew cab 4x4 that has a problem starting also, I just replaced the controller/relay and still just clicks... same as the old one.. i did check to see if i had resitance at the glow plugs .. but didnt read the results thinking as long as i had resistance they where good.. i did talk to the orginal owner and he has never placed the G/Ps ... I also have a tach issue it only reads half the RPM (about 350 at idle)... this truck has been sitting for about 4 yrs and is in great shape (like knew). I also just replaced the tach/cam sensor also no help. does any- one have any ides. ... has any one ever bypassed the controller/relay and put the G/Ps on a toggle swicth using a old style ford start relay?

[proturf]

Well, I went out last night... turned on the ignition switch and the "wait to start" light went out and then it clicked!!! Started right up without hesitation! Go figure! I would like to be proactive and resolve the problem before it happens again. I talked (by phone) to some mechanic friends of my son. They still highlighted to check continuity and then resistance to the GPs... and then to check the tightness of the connections on the controller. I was wondering if there could be an electrical issue in the ignition switch itself. Any other ideas? I have not tried to start it yet today... so who knows??

[cdnsarguy]

We normally do NOT put a manual overide switch on the solid state GP system..... it has a very good serviceability rate...... when GPs are working. Be careful at the controller live wires are full power from both batteries. If you want the test proceedure for the GP controller email me......... cdnsarguy@yahoo.ca