80 Series Crank No Start

[jonheld]

From my original post, bought it last summer, drove it 20,000 miles and until last Thursday, just died.

I'm going through things in my head. Please correct any statements.

No stored error codes and you have a CEL with the key in the on position.
You verified strong spark, fuel, and compression according to the FSM.
You verified that all the injectors are firing.
You did not remove the distributor and the adjustment bolt is tight.
You checked the condition of the inside of the cap/rotor or replaced them with OEM parts.
Spark plugs are back in place and tight.
All fuses in both locations have been verified with a meter, not eyeballs.

 

[smallv8]

I'm going through things in my head. Please correct any statements.

No stored error codes and you have a CEL with the key in the on position.
You verified strong spark, fuel, and compression according to the FSM.
You verified that all the injectors are firing.
You did not remove the distributor and the adjustment bolt is tight.
You checked the condition of the inside of the cap/rotor or replaced them with OEM parts.
Spark plugs are back in place and tight.
All fuses in both locations have been verified with a meter, not eyeballs.

100% Correct.

 

[smallv8]

100% Correct.

Pulled egr to confirm was indeed closed and not stuck open. Compressed air flows to tailpipe no issues through egr tube.

 

[smallv8]

Pulled egr to confirm was indeed closed and not stuck open. Compressed air flows to tailpipe no issues through egr tube.

Update: Rechecked compression using different gauge and cylinder 1 and 2 and were low 60-80 (raised slightly with cap of oil down the jug). Doing valve adjustment per maintenance schedule in FSM in am.

 

[smallv8]

Pulled egr to confirm was indeed closed and not stuck open. Compressed air flows to tailpipe no issues through egr tube.

Nice tool to heat and expand parts that have 264k miles and no flame. Worked great with brake fluid as lubricant. Re-attached with hitemp never-seize..

 

[jonheld]

I'm staring at your cold start injector and it looks like it's never been touched.
You said you verified fuel pressure according to the FSM. Please confirm.

 

[jonheld]

You mentioned that you were going to do a valve adjustment.
Please make sure the valve timing is correct according to the FSM as outlined in step 3 BEFORE you start.
The 3FE used composite hubs for the timing gears, as opposed to solid hubs in the 2F. In VERY rare cases, the 3FE can skip timing between the crank and cam gears if the composite has broken down.

And yea, I'm reaching now because this motor should be running.

 

[smallv8]

I'm staring at your cold start injector and it looks like it's never been touched.
You said you verified fuel pressure according to the FSM. Please confirm.

Verified with a better compression gauge cylinders are very very low. Valves have not been adjusted in last 15k miles, not sure if last owner even did one. We heard the cold injector operate.

 

[smallv8]

You mentioned that you were going to do a valve adjustment.
Please make sure the valve timing is correct according to the FSM as outlined in step 3 BEFORE you start.
The 3FE used composite hubs for the timing gears, as opposed to solid hubs in the 2F. In VERY rare cases, the 3FE can skip timing between the crank and cam gears if the composite has broken down.

And yea, I'm reaching now because this motor should be running.

View attachment 4137879

Agree, it should be running. Will double check per FSM. Did not know timing gears had composite hubs, thank you.

 

[jonheld]

Verified with a better compression gauge cylinders are very very low. Valves have not been adjusted in last 15k miles, not sure if last owner even did one. We heard the cold injector operate.

Have you checked FUEL PRESSURE according to the FSM page FI-47???

 

[smallv8]

Have you checked FUEL PRESSURE according to the FSM page FI-47???

Yes. 46 psi.

 

[smallv8]

You mentioned that you were going to do a valve adjustment.
Please make sure the valve timing is correct according to the FSM as outlined in step 3 BEFORE you start.
The 3FE used composite hubs for the timing gears, as opposed to solid hubs in the 2F. In VERY rare cases, the 3FE can skip timing between the crank and cam gears if the composite has broken down.

And yea, I'm reaching now because this motor should be running.

View attachment 4137879

Verified TDC cyl 1 per FSM, Adjusted valves per FSM. With a brand new timing gun opened this morning we are getting erratic strobe at dimple when cranking. Pulled HT lead an set to ground with screwdriver and sparks seems strong. Coil/Ignitor resistance checks out along with pick up coil resistance. She WANTS to fire, but doesnt. Trying with a different coil once it's delivered.

 

[smallv8]

Verified TDC cyl 1 per FSM, Adjusted valves per FSM. With a brand new timing gun opened this morning we are getting erratic strobe at dimple when cranking. Pulled HT lead an set to ground with screwdriver and sparks seems strong. Coil/Ignitor resistance checks out along with pick up coil resistance. She WANTS to fire, but doesnt. Trying with a different coil once it's delivered.

Got a lot of us stumped on our side, myself included who owns several cruisers. Two of my buddies are Engineering directors for new vehicle/ev division for GM. We all have built several engines each in our lifetimes and this is confusing. Engine should fire up. Im going to triple check grounds and wait for new coil, I think original coil is working properly, my buddy thinks its erratic.

 

[Old Nick]

Got a lot of us stumped on our side, myself included who owns several cruisers. Two of my buddies are Engineering directors for new vehicle/ev division for GM. We all have built several engines each in our lifetimes and this is confusing. Engine should fire up. Im going to triple check grounds and wait for new coil, I think original coil is working properly, my buddy thinks its erratic.

@jonheld is the master concerning your engine. I’ve been following this as a learning exercise.

Where grounds are concerned, did you check the one that runs from the block to the firewall? I’m a 94 owner so not the same engine, but it’s worth checking.

 

[smallv8]

@jonheld is the master concerning your engine. I’ve been following this as a learning exercise.

Where grounds are concerned, did you check the one that runs from the block to the firewall? I’m a 94 owner so not the same engine, but it’s worth checking.

Yes, jons been great through this whole process. Will be triple checking grounds tomorrow. Its a texas truck and very very clean and original. Ty

 

[Old Nick]

Yes, jons been great through this whole process. Will be triple checking grounds tomorrow. Its a texas truck and very very clean and original. Ty

You’re going to figure this out. It’s a nuisance but you’ll get there.

 

[landtank]

So was blocking the booster not Done, or Not the problem?

 

[smallv8]

So was blocking the booster not Done, or Not the problem?

We did not try this. Will try tomorrow.

 

[smallv8]

We did not try this. Will try tomorrow.

Update: Compression still at low 60psi on each cylinder when both valves closed on each. Have to travel out of state for a week, squirted MMO down jugs to give tired rings some love. Will be back in a week.

 

[smallv8]

Update: Compression still at low 60psi on each cylinder when both valves closed on each. Have to travel out of state for a week, squirted MMO down jugs to give tired rings some love. Will be back in a week.

Update:

Travelled for a week. 2-3 oz of mmo down each jug last Tuesday, shop rag in each hole. Pulled shop rags and turned over, no fluid out so i imagine its all seeped into crankcase. Shot more mmo down jugs. Doing compression check w/in next few days. Will put new oe plugs back in and new coil, then fire.

If to no avail; putting spare 3FE with 60k I have in stock and rebuild original.