1991 OCC TBI Coil Bad?

My 1991 OCC with 305 TBI coming home this morning, her engine just quit in the middle of the road.  No bang, no fuel sputter, no weird noises, no visible damage anywhere. Starter cranks the engine but it doesn't turn over.  Fuel pump went last year and was replaced, but that had different symptoms.  (Back then she tried to start but sputtered and died like a mower running out of gas.)  Checked two different plugs with a plug tester, no light.  tested the coil wire and no light between the coil and distributor.   I then tested the spark tester on my known running 70 Olds, just in case the tester wasn't working, and it flashed like it should.  No codes in the ECU. I have a replacement coil, but is there anything else I should I check before I replace it?

Starter cranks but doesn't turn over - Can you clarify what that means?

Ignoring that bit of confusion, do you have power to the distributor during cranking?

It never tries to fire. Starter just keeps turning the engine. I have to get the air cleaner off tomorrow to check the injectors but I can smell fuel as it turns. I'm working 12s at night right now so short of time to work on it. When I put the spark tester on the coil wire to the distributor I get no flash and no flash when attached to any plug. I checked all the fuses and none were blown. What other wire on the distributor should I check? The two plugs on the ignition module maybe?

It could be anything from the ignition switch to the wires from the detector coil to the module in the distributor. Check for B+ at the coil input (pink) with the Ignition on. You may have to remove the distributor to check the other wires. It could be the ignition module.
Fuel pump, and injectors appear to be good.

My wild guess is the ignition module...

Finally got Bertha running today. I replaced the coil on Friday and was unsuccessful. Snow yesterday hampered efforts but I found chart C4 in the shop manual and was able to run it down to the HEI module today and voila, she is now running. Verified timing and go to go. luckily I had both coil and HEI module in my spare parts collection. Thanks for all the help!
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I don't think I set the distributor back to the right spot, now she hesitates and seems sluggish and jumpy. I'll have to recheck the timing, I think I may have accidentally retarded it. The marks were really hard to read especially through the tube thing as I was trying to get it to zero. It was at +2 before and was pinging. The pinging is gone but the car doesn't seem as spritely, well spritely for a 4500 pound, underpowered wagon.

Remember to disconnect the connector on the PS valve cover when you are setting the timing.

I disconnected the ECM plug last time but I had trouble seeing the mark with the timing light. Apparently, I had retarded it like 10 degrees, off the marks. I used my 80's timing light instead of the modern one and its light was much brighter and I was able to see the numbers on the mark. It is at 0 now and has plenty of power but the constant pinging under load came back. I wonder if I retard it one degree at a time if I can calm that. Does anyone else have problems with pinging under load?

By the way, what is the metal tube above the timing marks for? It sure doesn't point at the marks.

Make sure your knock sensor is good.

My 87 Pontiac with 307 pings alot under load with regular unleaded but with mid grade it pings less and with premium it didn't ping at all.

I hope you put heat sink compound on the module before you installed it. Do not use dialectic grease.

Yes, I found a syringe of it at Best Buy. They call it thermal paste. I replaced the knock sensor a couple years ago. After I drove more today the ping was less but not gone.

Turns out two spark plugs were loose in the block. Tightened them, added Lubegard to the tranny, and now she runs smooth again. I unfortunately had to recrimp one of the plug wires because it pulled out trying to remove it.

I replaced the plugs and wires also which made her idle much better but did not effect the ping. I finally got a chance to retard the timing. Two degrees was enough to calm the pinging down to only under heavy load. Much quieter, but makes me wonder why it isn't good at 0 where it should be.

smparr wrote:

I replaced the plugs and wires also which made her idle much better but did not effect the ping. I finally got a chance to retard the timing. Two degrees was enough to calm the pinging down to only under heavy load. Much quieter, but makes me wonder why it isn't good at 0 where it should be.

Did you check to make sure that TDC is marked correctly on the indicator. I have seen them a lot more off than that, especially when the damper gets old.

If the rubber in the damper is broken the outer shell can move.

How do I check?  Is that where I remove plug 1 and check the notch when it is at the top of the stroke? The car is it 131,000, doesn't seem that much for a 32 year old SBC.

smparr wrote:

How do I check?  Is that where I remove plug 1 and check the notch when it is at the top of the stroke?  The car is it 131,000, doesn't seem that much for a 32 year old SBC.

I works the best if you have an indicator the reaches into the cylinder but a piston stop works also.  You have to take your time to get right at the center of the stroke.

With rubber dampers, time is at least as important as miles. The one I took out of my 96 RMW with similar miles was very cracked up and brittle. I didn't both to check it as it was needing replacement anyway. It has gotten very hard to find an non race style, stock style, damper these days. When I was looking for one, almost all were poor quality, cheap, Chinese knockoffs and they had terrible failure rates in just a couple of years, according to the reviews. I finally found one that was decent and NAPA for the LT. It cost a lot more but it was a very nice piece. Don't recall where it was made, though.