6.5 turbo starting problem

[sdragracer]

I have a 1993 GMC 6.5 turbo diesel and i am having trouble with it cranking when it gets hot.
Heres some background on this truck,replace the liftpump and the oil pressure switch already.The truck cranks and run fine when first started in the morning glow plug comes on goes out hit the key it starts,but when i drive for a while or [seems when it gets hot] if you turn it off this truck will not start and i notice that the glow plug light doesn't come on.If i use starting fluid it would start. Now even spraying it doesn't want to start all the time now.Can someone put me in the right direction to where to start looking?

[Jake]

This may be a PMD issue, which is well documented in the stickies. Is your PMD still on the injection pump (stock location)?

Jake

[Jess_sr]

93 has no PMD.

Most likely cause is a worn out IP.
Next time you get it hot shut it down for about 10 to 15mins.
Then see if it will start, if not hose down the IP for a min or two then try to start it again. If it fires up right away it's the IP

Don't use starting fluid EVER if you care about your truck.

[sdragracer]

Where would the IP be on the 93 6.5 and how much water does it take to cool it off before it will start?

[FloridaHorseman]

Originally Posted by sdragracer

Where would the IP be on the 93 6.5 and how much water does it take to cool it off before it will start?

The Injection Pump is just about dead center on the top front of the engine. Your throttle linkage is connected to it. It only takes about a quart of water (NOT COLD!) poured on it to get a hot start. The IP is probably worn internally and does not produce enough pressure to the injectors because the hot case expands. Water contracts it enough to start working again. There's no fix for that condition other than replacing the IP... or hauling water everywhere you go.


The glow plugs on your '93 won't come on if the engine temp is at or above 125f. Many of us have put a manual GP override switch in similar trucks. ~FH

[sdragracer]

Jess,i tryed the water on th IP and it still didnt start without putting a squirt of starting fluid is there anything else i can do to check my IP or maybe is something else.Keep the replies coming.

[Jess_sr]

Is your starter still turning the motor over at the same speed hot like it is cold?

And as for the water test, I used the garden hose on the entire pump for about a full min or so.
It's the middle of the summer, the water in the hose is much warmer at least here anyway. It's not like your going to crack something IMO..
I suppose a small amount may work if you know the exact spot to apply it but sure as hell don't.
That pump must be at least 200 deg after a hot soak.
Something with that much metal is not going to cool down to say 100 or less with a drip of water.

[sdragracer]

So it takes a lot of water, i was using a water sprayer.The engine spins fine for a while until the battery starts going down.

[reapersquadron]

Originally Posted by sdragracer

Jess,i tryed the water on th IP and it still didnt start without putting a squirt of starting fluid is there anything else i can do to check my IP or maybe is something else.Keep the replies coming.

NOO Never use starting fluid! Unless you want to destroy your engine never use starting fluid. It even says on your air box not to use it, unless the 93 didn't have it. If you use starting fluid in these engines from what I have read you will blow out the precombustion chambers and a lot of bad things will happen. Before you go to start it put the truck in reverse and then turn the key to prime the fuel system some. Then when you are cranking push the throttle some to add extra fuel. Correct me if im wrong anyone.

[Diaric]

Originally Posted by sdragracer

I have a 1993 GMC 6.5 turbo diesel and i am having trouble with it cranking when it gets hot.
?

if it cranks slower when hot your starter may have issues. make sure it still has the heat shield on it.
the cables will also conduct electricity worse when hot if they are wearing out