will not start when hot

[arrowsmith]

93 Will not when hot unless I bleed the injectors. Will start right up when cold. the Injector pump has about 100,000 miles on it.

If I only stop for about 5 min. it will start but has to crank a lot.

Could this be the injector pump. The lift pump has about 7000 miles on it.

Arrowsmith

 

[BushWakr - RIP]

It sounds like you're having trouble with the start/stop solenoid.

The solenoid is located on the firewall side of the pump, about 1/2 way down and just above were the injector lines connect.

The solenoid has two wires with spade connectors on them.

One wire is blue, the other is black.

The only thing you can do is remove the solenoid and check the spring loaded plunger operation.

The plunger has a black rubber tip on it and that is one item that can fail. Normally you'll see a piece or two missing from it. That means the thing is not doing it's job.

To test the solenoid itself, you need to pull the solenoid body, it's internal spring (like a ballpoint pen spring only tougher) the metal cylinder and rubber tipped part out.

Put the parts back into the solenoid once it's all out, and make sure you have a protective grip on the plunger end. Apply 12V to the metal post on the solenoid and see if the plunger pops in and out cleanly.

If it works ok and, there is no damage to the rubber tip then you're problem may be in the signal voltage from the second wire.

One wire is "trigger" voltage to open the solenoid and, the second wire is "maintainanence" voltage to hold it open.

With the key "ON" check each for power. One should be active while the other is dormant (I believe, correct me if I'm wrong here guys) With the engine running check if the second wire is active.



That should get you started..... on the road to diagnostics/fixing...



pastor bob..... ps: I really suck at electrical things...

 

[arrowsmith]

I don't think it is the start/stop solenoid because it will start when hot if I bleed the injectors. I had one solenoid stick when hot and got it started by pouring ice water on it. It always starts when cold. It is getting air maybe when shut off hot. Could the pump be making the fuel foam? Does the return lines to the tank have pressure? If yes wouldn't they leak when running. If no could they be sucking air when shut off? I don't know if it is because it is hot or that it has been running for several hours.

I can drive across town and it will restart.

Arrowsmith

 

[bgilbert]

After truck is hot and won't start, when you're cranking it, do you get smoke from the exhaust?

 

[dpuckett]

Shut off solenoid

Pastor,

I'm not sure you are entirely correct, at least that isnt how my pickup is set up. Mine only has the blue hot wire to energize the solenoid, and another nonIc truck has it that way, too. I think the black (which my pickup lacks altogether) may be a redundant ground.



Onto the problem at hand... ... Guys? I'm out of ideas here.



Daniel

 

[arrowsmith]

there is two wires to the solenoid one is the hot wire from ingition and the other goes to the thermo switch for the K. S. B.

What I can't understand is where is the air going after it cools off.

 

[arrowsmith]

Here is the story. I was on my way to CA. from Mo. when in Kansas I could smell diesel when I stoped. The lift pump was wet. Changed the pump in Co. Went to Death Valley(119 degrees), untill then it always started but would crank more than normal. I thought the fuel solenoid was sticking. A differant one had stuck befor when hot and ice water made it work. So after messing with that and had the battery low I removed the plunger and put the old lift pump back on. Had to get a jump start and bleed one injector line befor it started. After that it always started but would crank more than normal. I wouldn't shut it off unless I was stoping for a while. Got home put the plunger and new pump back. Went to Florida. At first rest stop (about two hours driving) it wouldn't start. I cracked three lines at injectors and it started after pumping the air out. Didn't shut it off unless stoping to eat or sleep. Haven't driven execpt around town after that

Arrowsmith

 

[arrowsmith]

don't know if it has smoke from the exhaust

 

[cwienenga]

do you get a lot of foam out of the nozzles when you bleed them? how does it run before shutting off,(any roughness at idle?).

It's possible for an injector to not seal completely and will pump combustion backwards when running and airate the fuel. maybe it takes awhile and after sitting the pressure bleeds off through the return? just a thought.



cliff

 

[bgilbert]

don't know if it has smoke from the exhaust

Well we need a few more details, I have a cummins troubleshoot manual in front of me, and gives plenty of possible problems, :truck won't start -smoke or no smoke from exhaust... no smoke points to solenoid, then air intake or exhaust plugged, fuel filter plugged with h20, inj pump not gettin fuel or fuel is aerated. :truck won't start- smoke from exhaust... solenoid, crank speed to low, intake heater, insufficient intake air, air in fuel system or fuel supply is inadequte,, lift pump malfunctioning, contam fuel, worn or malfun inj pump or inj pump out of time, one or more worn or malfun inj's. Nothing about won't start when hot though, as most gasser manuals would give troubleshoot advise on...

 

[cwienenga]

most of those items listed are ruled out by the fact that after bleeding the truck runs ok at all speeds apparently

cliff

 

[matches]

How hot are we talking? What about the possibility of vapor lock?

Nver seen it on a diesel but my old gasser would do the same thing and after bleeding of the air would start, also how many miles on the truck? Can you pinpoint the start of the problem to the new lift pump or the DEATH VALLEY CURSE? My CTD lives and breaths in 120 degree weather everyday, and it always start right up. As I have noticed with changing fuel filters the high pressure injection pumps make short work of that extra air, just to confuse you more.

 

[arrowsmith]

I have just about run out off guesses. It runs fine and still gets 18 mpg. The only problem is getting it running. I don't know if it is heat or time that makes it not start. I have thought about vapor lock(I also drive a Flathead Ford they do that) Today I'm going to check to see if the fuel heater is on.

It has 200,000 on the truck and about 100,000 on the injector pump. I'm about ready to blaim the injector pump Don't know how it could be doing that though.

Befor not starting in Death Vally it would always start but crank longer than normal.

 

[matches]

was the pump re-built? and if so by a good shop, I would guess and say it was the pump, they must have some way of getting rid of that air, lke I mentioned before, and maybe yours is not?BD tried to sell me a direct replacement 300 hp pump, if you have the money just do it anyway. If the fuel heater is on you will hear a buzz and your volt guage would read low, I doubt it is on for that long without burning out.

 

[CGauthier]

I had this exact problem, but it was on my 7. 3 Ford. That was a real PITA. How many places I had to sit around waiting for the thing to cool down. It was the injection pump. I guess when it would heat up something inside would stick because of the expansion I suppose... it wouldn't pump any fuel at all-what really threw me for a loop was a rebuilt one i got did the EXACT same thing... . good thing for me is that i wasn't doing it myself; otherwise those goofs at Western Turbo wouldn't have honored the warranty