6.5 turbo diesel hard starting

ScottG wrote:
I test drove one of those back in the day. It's still the only stock turbo truck I have ever driven that would lay rubber from a stand still (had 4:10's).

This one has the 4:10 gears and a 5 speed manual. The engine is a Peninsular diesel. The early Peninsular diesels had almost as poor of reputation as the stock 6.5 did. I hope the new ones are better. They use a new 6.5 block which has a little more casting around the main bearing supports. The new heads, along with a different thermostat housing and high output fan and water pump are supposed to provide much better cooling. It has a steel crank and lower compression pistons along with a larger turbo. The lower compression pistons and larger turbo provide much more air to keep the engine cooler as well. The mechanical injection pump is upgraded to provide a higher fuel delivery. It has a lot more power than the stock engine had (I believe it is supposed to make 300 hp) and is getting extremely good fuel economy. The truck pulled a 14000 lb gooseneck and returned just over 13 miles per US gallon.

"To check the glow plugs can I unplug them and measure the resistance to ground? What should it be? "

All I have done to check glow plugs is unplug and use a test light by attaching alligator clip to positive side of battery and touch the spade on the end of the glow plug. If the test light glows it's GOOD. If it does NOT light it's BAD plain and simple.

Glow plugs are a major PITA!!! They don't seem to last very long on the 6.2/6.5 engines.

If you have a fuel filter like pictured below with a primer button hit it before starting and see what happens.

Lift pump may be the problem if the primer method works.

Turtle n Peeps wrote:

4x4ord wrote:

Turtle n Peeps wrote:
Check the glow plugs one by one. You're going to have several burnt out.

They were all replaced when the new engine was put in as were the injectors and injection pump. The truck behaved like this before replacing the engine as well. It takes excessive cranking as it smokes and struggles .... as soon as it starts you can shut it off and it will instantly restart.

Were they rechecked? New means nothing! If I had a dime for every part that failed out of the box I would be rich. CHECK THEM! Was the wiring to the glow plugs checked? Was the continuity to the GP's checked? Was the timer checked?

If all good, the next I would go after is cranking speed. That could be anything from bad cables to a dragging starter; even a bad new battery.

The next I would go after is a compression check.

All of these things have to be checked one by one. My 93 would start down to about 25 degrees with 3 GP's burnt out. When the 4th one burnt out it would not start.

Another thing to check is the lift pump. Can you hear it running? If not 90% of the time it will be the oil pressure switch. Check that too. More than likely it's not a fuel problem if you see white smoke. It's going to be a heat deal.

To check the glow plugs can I unplug them and measure the resistance to ground? What should it be?

The lift pump does run and pump fuel....I've run a wire directly to the pump bypassing the oil pressure sending unit...It's not real obvious as to whether this helped any or not. .After sitting for a period of time the truck will often fire as soon as you cycle the glow plugs and hit the starter. Usually it doesn't start though. I am guessing that initial firing is from the fuel left in the injection pump.

I'm wondering if there is a check valve anywhere in the fuel supply line? Maybe in the lift pump? There is no sign of fuel leaking on the ground.

I test drove one of those back in the day. It's still the only stock turbo truck I have ever driven that would lay rubber from a stand still (had 4:10's).

Next PM try a lighter weight motor oil. Maybe 10w30 diesel oil. Canada is a colder climate. Oil may just be thick. Since this has happened on both engine. I believe this is the old indirect oil fired GM system. But as others have said make sure glow plugs are working. But they only warm cylinder, not the oil that fires injectors. Or plug it in and see if starts.

4x4ord wrote:

Turtle n Peeps wrote:
Check the glow plugs one by one. You're going to have several burnt out.

They were all replaced when the new engine was put in as were the injectors and injection pump. The truck behaved like this before replacing the engine as well. It takes excessive cranking as it smokes and struggles .... as soon as it starts you can shut it off and it will instantly restart.

Were they rechecked? New means nothing! If I had a dime for every part that failed out of the box I would be rich. CHECK THEM! Was the wiring to the glow plugs checked? Was the continuity to the GP's checked? Was the timer checked?

If all good, the next I would go after is cranking speed. That could be anything from bad cables to a dragging starter; even a bad new battery.

The next I would go after is a compression check.

All of these things have to be checked one by one. My 93 would start down to about 25 degrees with 3 GP's burnt out. When the 4th one burnt out it would not start.

Another thing to check is the lift pump. Can you hear it running? If not 90% of the time it will be the oil pressure switch. Check that too. More than likely it's not a fuel problem if you see white smoke. It's going to be a heat deal.

newman fulltimer wrote:
get a better quality of batteries and need the oem battery cables

Batteries are new.

Turtle n Peeps wrote:
Check the glow plugs one by one. You're going to have several burnt out.

They were all replaced when the new engine was put in as were the injectors and injection pump. The truck behaved like this before replacing the engine as well. It takes excessive cranking as it smokes and struggles .... as soon as it starts you can shut it off and it will instantly restart.

get a better quality of batteries and need the oem battery cables

Check the glow plugs one by one. You're going to have several burnt out.