94 Turbo won't start when hot, this is after the IP rebuld!

velacreations

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Ok, around Christmas, I did an injector/IP change on my '94 7.3L turbo. We also changed all lines, o-rings, fuel pump, filters, radiator, glow plugs, etc. The truck runs great after the work, but one thing doesn't: it won't start when hot. It basically happens after the truck has been sitting hot for 30 minutes.

I've tried the water on the IP trick, and it starts fine. So, I know that's the problem. But, the issue is, we changed this IP about 6 times, different parts, different rebuild shops, new and used, and we still have this issue. The mechanic at the pump lab finally threw up his arms. All of the pumps tested fine, but had the same issue on the truck.

Other than the hot starting, the truck runs great. It has lots of power, some black smoke really pushing it up hills, but otherwise no smoke, no issues.

I can start it cold just fine, run it up to temp, then shut it off. If I start it again in 10 minutes, it starts. If I wait 30 minutes, it won't start, just cranks. I basically have to take a bottle of water everywhere I go, just in case.

It is very annoying, and we've tried so many things, I am kinda lost. The mechanic thought the pump was the issue, but after changing it out several times with several different pumps and rebuild shops, and all the pumps tested fine, he thinks it has to be something else. We've basically been fighting this since December. I'm starting to think I just need to add a few quarts of motor oil in my diesel tank at every fill up.

Any idea what else could be wrong with it?
 
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DesertBen44

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So let me get this straight, the problem has persisted the same and you have swapped how many pumps in? The only thing I have read on here that cause a problem like yours is a pump that is D-U-N done.
 

Black dawg

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What is hot cranking speed? this is atleast as important to hot starting as it is to cold starting.
 

riotwarrior

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Ok, around Christmas, I did an injector/IP change on my '94 7.3L turbo. We also changed all lines, o-rings, fuel pump, filters, radiator, glow plugs, etc. The truck runs great after the work, but one thing doesn't: it won't start when hot. It basically happens after the truck has been sitting hot for 30 minutes.

I've tried the water on the IP trick, and it starts fine. So, I know that's the problem. But, the issue is, we changed this IP about 6 times, different parts, different rebuild shops, new and used, and we still have this issue. The mechanic at the pump lab finally threw up his arms. All of the pumps tested fine, but had the same issue on the truck.

Any idea what else could be wrong with it?

Contact Mel at Conestoga Diesel


What is hot cranking speed? this is atleast as important to hot starting as it is to cold starting.
The water on the IP cooling it is the key...if that's getting it to start...it's the IP's

My take...

Try another pump builder one known for extreme quality!

Just sayin....
 

velacreations

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Try another PUMP supplier....

Just sayin

Al
yeah, I have tried a few. Rebuilt, used, etc. We've gone through 4 suppliers and at least 6 pumps.

Is there anything else it could be? I know it is the IP, cause the water trick works. But, is it that the pumps are worn out and eventually they will fail? Any other remedy instead of throwing more pumps into it?
 

icanfixall

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Well it sounds like all the pumps are having the same issues of worn out so a heat soak problem comes up. Why 6 of them are having the same issues has to do with the rebuilding process. As posted its time to try Conestoga Diesel InPa. USA. Mel is a great person to work with and ripping customers off is not something he does. Hes honest to a fault. He has 4 differant DB2 pumps that will work well on your engine.
 

velacreations

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well, I'm not in the States, so I don't have that option, really. Sending a core, etc, it would take a few months to be back on the road.

Will these pumps eventually fail, or can I keep it going for a while like it is?
 
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bbjordan

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I had a similar problem when I was testing out the injection pumps that I have horde'd. After the I put the last one on, it had the hot start problem. No problem, I thought, I'll just put the known good one back on. It too now had the hot start problem. ***? So I replaced the return line kit, o-rings, and olives. No more hot start problem. It also started faster when cold. You could also try the electric fuel pump mod.

BTW, what timing are you running?
 

velacreations

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were you getting any smoke before the return lines? Was it showing any other symptoms, there? We did change that out, but not after the IP fiasco. It doesn't smoke on startup, though.

I don't know on the timing, they set that in the garage.
 

Black dawg

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Contact Mel at Conestoga Diesel



The water on the IP cooling it is the key...if that's getting it to start...it's the IP's

My take...

Try another pump builder one known for extreme quality!

Just sayin....

If the cranking speed is to slow, water over the pump can and will help starting. I have seen this several times.

I do agree though, if all else checks out, it is time to get a pump from elsewhere. Makes me wonder if they are not finding anything wrong with the pump and just giving it back. Can you come up with a known good pump to try. If all of these pumps actually have heat soak issues, you have REALLY bad luck.
 

velacreations

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If the cranking speed is to slow, water over the pump can and will help starting. I have seen this several times.
I will look into it, but it seems to crank fine.

I do agree though, if all else checks out, it is time to get a pump from elsewhere. Makes me wonder if they are not finding anything wrong with the pump and just giving it back. Can you come up with a known good pump to try. If all of these pumps actually have heat soak issues, you have REALLY bad luck.
Well, I saw the pumps, and we tried several different sources, but I guess it is possible that they are just all junk. It just seems unlikely to me, that's why I'm looking for anything else to try. After 3 pumps, we started wondering about the chances...

Like I said, other than the hot start, the truck runs better than ever, with lots of power. I'm starting to worry for how long, though...
 

riotwarrior

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well, I'm not in the States, so I don't have that option, really. Sending a core, etc, it would take a few months to be back on the road.

Will these pumps eventually fail, or can I keep it going for a while like it is?
Why is a known quality builder not an option?

Pay the pump price, get it, when you install it you return your core.

Nothing hard not overly difficult.

Al
 
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