Help! Car runs great then dies. Won't start back up.

[drewguillory]

Here's whats going on with my car:

It starts right up and drives great.. after awhile (about 20 min) it begins "skipping" as if starving for fuel, then it dies. The car will not restart until it sits and rests
for about 10-15 minutes... then fires right up again. Sometimes I can city-drive with no issues, but the moment I hit the highway in 4th/5th gear, car sputters and dies.

Also, I should point out that I'm no longer running K-Jet, as my D has been carbureted. As far as I know, fuel pump is fine.. spark is fine.. timing is fine.
I suspect the coil in the distributor is going bad. Is it called the Pulse coil, Impulse coil, or Pickup coil?
Anyone know how to test it, and/or have any other ideas?

Thanks,
Drew

[Bitsyncmaster]

Yes it sounds like a pickup coil, spark coil or spark ECU failure.

[bikergurl2000]

I wonder if he has already replaced his spark coil and spark ECU? Is it difficult to replace the pickup coil inside the distributor?

[David T]

Actually this sounds more like vapor lock to me. One way to eliminate that would be to use a pressure regulator and dump the excess fuel back to the tank. Another possible solution would be to reroute the fuel line and insulate it from any heat sources. You might also have to add a heat shield for the carburetor or at least add a block to raise it above the motor a little. A bad impulse coil is also a possibility. Check for spark the next time it dies before it has a chance to cool. To replace the coil is a pain, you must remove the distributor but in your case at least you have better access to it!
David Teitelbaum

[sdg3205]

My vote is your coil is toast. $36 bucks from Dmc. I had the same issue. Is your coil the original?

[DeLorean03]

I suspect the coil in the distributor is going bad. Is it called the Pulse coil, Impulse coil, or Pickup coil?
Anyone know how to test it, and/or have any other ideas?



Yes, next time this happens, disconnect the plug where the electrical/ignition distributor's tachometer wire hooks up to the rest of the car. Take your multimeter and measure ohms. You should be getting in the ballpark of 550 ohms or so. If you do, it is good. If not, time for a new one.

Lil' tidbit I learned from SpecialTAuto's website a while back. It is still on his website on this page: http://specialtauto.com/delorean-parts/electrical.html.

#2 in this picture is the wire you want to unplug - DO NOT unplug the side closer to the body of the distributor. Unplug the other end; it looks VERY similar to the connector on our cold start valve or control pressure regulator.

17065

[drewguillory]

Well guys, it's a mystery...

Yesterday a friend and I spent the afternoon swapping parts: spark coil, spark ECU, even swapped distributors (his is brand new). Nothing seemed to fix the problem.
At one point we realized I wasn't getting fuel to the engine, so we inspected the fuel pump... which was failing. I bought a new one and we installed it.
Problem solved, right? Nope, at least not entirely. The car would still "skip" and die on the highway. Either the fuel pump was going out over time or it coincidently
decided to crap out that day.

The next thing we did was swap carburetors... both of our cars ran fine. We swapped them back, and still both cars are running fine.
What's going on?!

Thanks for all the information and help.
-Drew

[David T]

The only thing you did that had any effect was messing with the fuel pump. Maybe the new one gives you just a little more pressure so it improved the symptom a little. I would still guess vapor lock. It is some kind of fuel delivery problem. Maybe the tank is not vented and you are developing a negative pressure in the tank making it hard for the pump to remove the fuel from the tank. Next time it dies, quick remove the fuel cap and see if that helps. Or just put the cap on loose and see if the problem goes away.
David Teitelbaum

[Ron]

I don't know, David...Since it still had similar problems after installing a new fuel pump but not after carb swaps, I would suspect the carb -- It's the only thing disturbed between bad symptoms and running OK, if I understand it all correctly. The float could of been hanging, the inlet filter may have been clogging in 4th & 5th due to high RPMs (classic), or ???

=====

If it does it again on the highway, pull over immediately w/o cranking it, remove the air cleaner (confirm choke plate is wide open), and look down the throat while working the throttle. If you see it squirting fuel, it was not vapor lock and probably not a fuel problem at all. Take a spare spark plug with you to put on an easily pulled plug wire and check for spark with the plug grounded to the block somewhere making it easy to watch.
Hopefully you won't have too ;-)