Anyone have any info on the hot start relay?

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Recently had an issue with starting my Delorean and during troubleshooting I ran across a line or two concerning the fact that the car was wired for a hot start relay in the tech info manual. From what I gathered, a relay can be installed if a hot starting problem is experienced in excessively hot regions of the country. Problem is, the relay socket provided isn't wired properly to allow a typical relay to active anything in the circuit so I'm assuming that there was a special relay provided to owners when they purchased the car new. Is this true or am I smoking too much wackyweed? Found my starting problem, the connector to the thermo-time switch was loose but I'm still curious about that hot start relay.

[Bitsyncmaster]

DMC never produced a hot start relay. Yes they wired in the socket. A normal relay will not work. I do sell my own designed hot start relay.

[Christian Dietrich]

And they work AWSOME!!!!!

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[Chris 16409]

The nice thing about Dave's relay is you can "delete" the ThermoTime switch from the fuel system. You can get a plug for the water pump and remove the ThermoTime switch completely. In effect it becomes a "cold start relay". But it will allow the cold start valve to fire regardless of engine temperature.

[Drive Stainless]

The nice thing about Dave's relay is you can "delete" the ThermoTime switch from the fuel system. You can get a plug for the water pump and remove the ThermoTime switch completely. In effect it becomes a "cold start relay". But it will allow the cold start valve to fire regardless of engine temperature.

How does Dave's relay activate the cold start valve if you delete the thermotime switch?

[Bitsyncmaster]

How does Dave's relay activate the cold start valve if you delete the thermotime switch?

My hot start relay activates the cold start valve after one second of the starter cranking. It does that with a hot or cold engine. It will only activate the CSV for four seconds so cranking longer than 5 seconds will not help getting the engine started. If you stop cranking then you can repeat the cycle.

I found my engine will start faster in the summer without the thermal time switch connected. So I just don't run the TTS at all. You can keep the TTS working if you want the instant CSV to fire with a cold engine.

So yes, I do consider the hot start relay to be a cold start relay also. I always recommend fixing any rest pressure problems but with my hot start relay, you should not have to do the "plug swap" if you have a hot start problem.

[David T]

If you have all of your cold start systems operating properly there is no need to add a "Hot Start Relay". Adding one is just treating the symptom, not the underlying problem. Typically it is most often a wiring problem or a bad TTS. Sometimes it is because someone plugged something INTO the hot start relay plug! When I troubleshoot a hard cold start one of the first things I check for is if anything is plugged into that plug. A lot of people think if there is a plug then something MUST plug into it! People also wire switches into that plug to deal with a hard HOT starting problem. That way you don't have to do the plug swap thing to get going when you have a bad fuel accumulator. In that case I say just replace the accumulator, not add a switch.

[Chris 16409]

My whole point is why mess with a thermotime switch when there is a modern replacement available.

DMC Thermotime Switch:
https://store.delorean.com/p-6265-sw...hermotime.aspx

These switches are now well over $150 so, it's more cost effective to get one of Dave M's relays. I'm not arguing against replacement of a fuel accumulator. Everyone with hart start issues should replace their accumulator. I'd just rather use a modern digital relay, then rely on a thermally activated switch designed sometime in the 1970's.

[Drive Stainless]

My whole point is why mess with a thermotime switch when there is a modern replacement available.

DMC Thermotime Switch:
https://store.delorean.com/p-6265-sw...hermotime.aspx

These switches are now well over $150 so, it's more cost effective to get one of Dave M's relays. I'm not arguing against replacement of a fuel accumulator. Everyone with hart start issues should replace their accumulator. I'd just rather use a modern digital relay, then rely on a thermally activated switch designed sometime in the 1970's.

Safe to say that Dave's relay allows for deleting the accumulator, too? That's a spectacular advantage, if so.

[Bitsyncmaster]

Safe to say that Dave's relay allows for deleting the accumulator, too? That's a spectacular advantage, if so.

No

If you have ever had a hot start problem, even firing the CSV may get you started but your engine takes about 60 seconds for all the injector lines to clear of bubbles.