6.5L Trouble starting 6.5L even when plugged in

[Codie]

Try to start my 6.5 its been plugged in in a garage go to start it and it took forever. Got it started let it warm up to 180° then shut it off try to start it back up and takes forever again like it was never warm. Any ideas what it could be?

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[Burning oil]

Glow plugs.

 

[Diesel Nut]

What year is the truck? Could be a bad lift pump, bad IP? Make sure you got around 6-8 Psi coming from the Lift pump.

 

[ReadinessRob]

I have the same problem with my 1989 6.2 , what I have surmised is that my fuel lines have deteriorated over the years due to pump fuel reformulation and have caused LP/IP problems. When, and if, it starts I have surge issues along with
what seems like loading[heavy raw fuel smell from exhaust] similar to a carbureted engine. Any help is also appreciated.


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[ak diesel driver]

we need a little more history as there are several reasons this could be happening

 

[ak diesel driver]

maybe if one of the mods could move it to the 6.5 section you'd get more replies

 

[ReadinessRob]

we need a little more history as there are several reasons this could be happening

Well, another probable issue is the mileage. It is documented with 399,000+ original miles. Everything appears to be original except for the starter, alternator, batteries, belts, hoses and tires. No mechanical fuel pump on the block just a crappy homemade block off plate made by the previous owner. Replaced the inline fuel pump thinking this would help. It did temporarily. Thought I would freshen up the old square fuel filter thinking it would help. That was the beginning of the nightmare for me and my suburban.

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[ak diesel driver]

I think the first thing I would do is take off the short return line coming off the IP and replace it with some clear tubing. but both the IP and the injectors are suspect with that many miles

 

[NVW]

We have two different posters here, can a mod separate the threads?

 

[ReadinessRob]

We have two different posters here, can a mod separate the threads?

Sorry, I didn't mean to hijack the thread.

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[NVW]

I have the same problem with my 1989 6.2 , what I have surmised is that my fuel lines have deteriorated over the years due to pump fuel reformulation and have caused LP/IP problems. When, and if, it starts I have surge issues along with
what seems like loading[heavy raw fuel smell from exhaust] similar to a carbureted engine. Any help is also appreciated.


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Sounds like the engine is just worn out, only reason I can see for raw fuel smell from the exhaust. That or the timing chain could be a tad stretched.

 

[NVW]

Sorry, I didn't mean to hijack the thread.

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No problem, it just confuses us sometimes.

 

[WarWagon]

To start a 6.5 IDI engine you need 100 RPM cold, 150 RPM hot. This means good batteries, cables, grounds, and brushes that all work in the starter. You can loose 1-2 brushes (of the total 4) and the starter will still spin the engine, but, too slowly. (Same with just one battery working and the other out to lunch - Not enough RPM to light the fire.) If the engine sounds like it is grinding over slowly - IT IS!!!

Sticking injectors cause this to hit, miss, miss, hit, and then finally start. Regardless ignoring the random hits this is what your engine should sound like with enough cranking speed:

Next it needs air free fuel. This means the system doesn't leak down overnight aka fuel runs back to the tank from an air leak anywhere on the engine. Air in the lines are the #1 troubleshooting step in the GM manual. The 6.2 fuel filter is known to leak air at several places. A fuel leak is a dead giveaway of a problem, but, air leaks in the fuel system don't always leak fuel.

Glow plugs are already mentioned. Raw fuel smell in the exhaust means the engine is getting some fuel, but, no glows, no compression, not enough RPM, or air in the lines causing havoc with the fuel delivery and all resulting in a no fire condition.

Taking forever to start is a problem that needs to be fixed ASAP. Don't keep grinding the starter in hope as it will just burn out.