Strange: No start, but then starts fine

[Stainless]

Now that I've tackled other more pressing issues, it's time to dive into this one. After the car has been sitting for a couple of days, I will go to fire it up and it will just crank and crank. No matter how long it cranks, it will not fire up.

What's strange is if I walk away for like 5 to 10 minutes and then come back, it will fire right up. It will struggle at first, but it then runs smooth once it gets going. So my routine has now been to go out to the car, crank it a few times, walk away, come back and start it successfully.

Anyone every come across something similar to this?

[DMCMW Dave]

Anyone every come across something similar to this?

Check your thermo-time switch circuit. Chances are you are not getting the cold-shot, or it is timing out too quickly.

[Stainless]

Thanks Dave! What is the proper way to test this? Do I look for a certain ohms or voltage across the terminals?

[Stainless]

Nevermind. Found the answer:

"Changing the switch is a much more effective way of troubleshooting the circuit because all of the grounds are switched through the TTS. It is impossible to determine exactly what is wrong with a meter or trouble light. Just change the switch. In the rare event this fails to restore the cold start operation, you must check the 12v feed to the injector using an independent ground. This power feed comes from the starter solenoid.

It is only present when the starter is spinning."

Thanks for pointing me in the right direction.

[Bitsyncmaster]

Probably the best way to check the cold start system is to pull the CSV and put it in a jar. Then disable the ignition (pull the white/yellow wire off the resistor block). Then crank it for 5 to 10 seconds. Your jar should have some gas in it. This test checks the whole circuit.

My car had a bad connection on a pin behind the bulkhead connectors. That stopped the CSV from ever working and I wonder if it left the factory that way.

[coreydmc]

check your RPM fuel relay

[David T]

Coreydmc makes a good point. If you are having trouble with the fuel pump, it doesn't matter if the CSV circuit works or not. One way to test this would be the plug swap. If the car starts right up that would prove out the fuel pump and the CSV. If it doesn't start then either the CSV is bad or the fuel pump isn't pumping. If it starts right up you probably have a problem with the wiring in the CSV circuit or the Thermo-Time switch is bad. Another possibility is a bad connection in the ignition circuit. Clean the terminals and connectors on the white ballast resistor on the firewall.
David Teitelbaum

[Stainless]

**Update** As it is starting to cool off again around here in the Rockies, my DeLorean started to crank a while before starting in cold weather. I was in Houston for a business trip this week and tried to think of an excuse to stop by DMCH again. I decided to stop by and pick up a thermo time switch while I was there to save on shipping.

I installed the new part this morning when it was nice and cold before starting the car. After hooking it back up, the car fired up immediately. Problem solved! That was easy. :)