I just bought a 1992 F350 2WD daully with a 7.3L IDI. My uncle is a diesel mechanic and happened to get me a set of Bosch glow plugs and a glow plug controller. With those replaced, my "Wait to Start" light is now working again.

When the truck is cold, I turn the key to on, give it NO throttle, and when the "Wait to Start" light goes out, I crank it. It fires right up, idles smoothly, and runs very well.

However, after it is up to temp, it is hard to restart. If I have it running even just for 5-10 minutes, and shut it off, it gives me a fight to get it restarted. I wait for the "Wait to Start" light to go out and crank it. It does nothing, so after a few seconds, I turn the key off and back on. When the light is out, I crank it again. Usually, when its hot, it will fire up on the 2nd or 3rd try. I have played around a little bit giving it throttle to get it to start while cranking, but it seems like it makes no difference.

Is there something I am missing about these non-turbo diesels to start them when they are hot ?

Also, has a new air cleaner, and I will be replacing the fuel filter this weekend some time. How bad are these to bleed the air out of the system? My Dads Cummins wasnt bad at all. Actually, we just filled the filter with diesel, stuck it in there, and then cranked it for a few seconds and it fired right up ...

 

Its likely your injection pump is worn, if everything is in good condition it should start right off when its warm, mine starts as soon as I hit the starter.
You could try spraying cool water on the ip when it is warm then wait a few minutes then try to start it. If it starts right up then most likely the ip is worn and will need to be replaced. Let us know how you make out

 

Alrighty ... That wasnt exactly what I was hoping to hear, but I guess I'll find out then soon enough.

When you start your hot, do you give it any throttle at all or anything ?

When its cold it fires up right away ...

 

Also, I guess its worth mentioning, it sat for almost 2 years. The tanks were almost empty, so I put 5 gallons in one tank, then started it to bring it home. Think it could possibly be from the old/bad diesel fuel? Thanks.

 

I agree with farmnfly. I have seen this problem before and it always seem to get worse with time to the point it won't start at all when its hot.

 

I forgot to tell you, when you step on the gas while cranking a diesel, it doesnt do anything. You are only pushing against the governor springs inside the injection pump and it will not have any effect on starting, but we all try it out of habbit when something will not start,
As for old fuel and sitting it may have some effect but probably not diesel is more like oil and sitting does not effect if as fast as a gasoline fuel vehicle, but you can try running some fuel additive for a few tanks and see if it gets better, it sure wouldnt hurt anything.

 

Ok thanks guys ... I have some of that Lucas upper cylinder lubricant stuff you add to the fuel ... Ill give that a shot tommorow until I go out to see what kind of other additives I can get my hands on around here in Pittsburgh.

I thought that about giving it throttle ... Since Diesels dont have a throttle body, no vacuum, you really arent changing the AF ratio. But the owners manual for the truck said something like on a cold start below freezing, crank it at WOT, above freezing, cold start, crank it at half throttle, and a hot start to crank it with the pedal in the fast idle position ... So it kinda threw me off ... I read it and was like what the hell ??? So I figured id give it a shot ... It actually seems to be getting better ... My dad moved my truck, and he let it run for about 10-15 minutes to see if he could pinpoint the antifreeze leak while I was at work at the garage ... He said when he shut it off, it fired up the first time he crnaked it, hot, after about 2-3 seconds ...

One thing I did notice is that it cranks alot slower than his Cummins does ... And it has two brand new Deka batteries. They are something like 1050 CA and 835CCA ... ( Like a week old, my girl friends dad, who I got the truck off of, got the batteries for it for me, he owns a battery shop ... )

 

You mite want to look into a new starter or put up a post on how fast should it crank, someone will have the specs. But I would guess that there shouldnt be any noticable difference in cranking speed. I heard from somewhere that a diesel should be cranking at least 200rpm