1991 D21 ignition problem?

[mazikowski]

I have a 1991 D21 with the KA24E. Before getting it, it seems to have been severely neglected all its life. Recently we replaced the oil pump and ever since we have had a strange (and most likely unrelated) problem. It will start but after running for 10-15 minutes if you turn it off it will not start back unless it sits for about an hour. If you start it, let it run for a little bit (30sec - 1 min or so) and turn it off, it starts back up without a problem. We have replaced pretty much the entire ignition system (including plugs, wires, cap, rotor, coil, ignitor [the little god-awful-expensive thing mounted to the coil bracket]) and are still having this problem.

Any ideas?

[mrecoolgar]

When the no start happens, have you verified spark and fuel ?
It could be a fuel issue.

[mazikowski]

I know it is getting fuel because after trying to start it a few times without success, you can smell gas really strong. Also, when it does start after trying a few times you can tell it is a little bit flooded. We've got a new distributor ordered so hopefully that will solve it. The Haynes manual suggests that the pick up coil could be shot.

[mazikowski]

Replaced the distributor today and still the same problem. If the truck runs for about 15 minutes it will not start back after you turn it off.

Any ideas guys? Seriously about to take it to a field and set it on fire!!!

[mrecoolgar]

Check the evap purge system for a clog.
It may be suffering vapor lock.
Look at any connections or collapsed or bad hoses.

[mazikowski]

I hadn't thought about the possibility of vapor lock.

I think we have it fixed now. Replaced the ECU coolant temp sensor and all seems to be well. Just wish that was one of our first guesses instead of spending close to $500 on a whole new ignition system. Whatever... new parts are good parts.

[mrecoolgar]

At least we are learning.
Without experience, diagnosis is difficult.

[mazikowski]

At least we are learning.
Without experience, diagnosis is difficult.

Exactly. Besides, like I said, having new parts that were more than likely due to be replaced soon anyway is an expense that would have been incurred anyway.