I har the pump running for a few seconds when I turn the key on, and have done this multiple times to try and pressurize the system. When it is warm even this WILL NOT get the engine to start. Steve #2700 ----- Original Message ----- From: content22207 To: dmcnews@xxxxxxxxxxxxxxx Sent: Thursday, February 07, 2008 5:30 PM Subject: [DML] Re: Warm Start Issue (David McKeen) As its name suggests, the cold start valve only operates on a cold engine. There's a thermal switch in the cooling system (side of the water pump if I remember correctly) that opens when the coolant heats up, severing the cold start injector's ground and preventing it from spraying. The hot wire to the cold start injector is live every time the starter circuit is engaged -- only the ground is severed. I seem to remember that the thermal switch has its own resistance heater as well, to prevent over use of the cold start injector even on a cold engine -- if you keep cranking the engine without starting, the cold start valve will eventually stop spraying. The CPR plug swap works anytime because its ground is always connected. You need rest pressure because DeLorean fuel injectors are mechanical. They do not spray without a certain amount of fuel pressure. On a cold engine, the cold start valve provides enough fuel for the engine to start, the pump to run, primary pressure to build up, and the mechanical injectors to start spraying. A warm engine will not use the cold start valve. If the injectors can't spray because pressure is missing (no rest pressure), no fuel will enter the engine. You can crank it all day and it won't start like that. Remember: The pump does not run and can not reprime the system until the engine is turning a certain number of RPM's. As Harold pointed out, the pump does run for a split second when the car is first energized. You can re-energize the car several times to build fuel system pressure (run the pump for several split seconds), then start a warm engine that has rest pressure problems otherwise. Bill Robertson #5939 >--- In dmcnews@xxxxxxxxxxxxxxx, "bitsyncmater" <david.mckeen@...> wrote: > > My car starts great cold. Is the cold start valve needed to start it > cold. If it was just used to start a warm engine than you may have > discovered where the problem lies. Bit then why does a longer rest > pressure time also fix the problem. [Non-text portions of this message have been removed] To address comments privately to the moderating team, please address: moderators@xxxxxxxxxxx For more info on the list, tech articles, cars for sale see www.dmcnews.com To search the archives or view files, log in at http://groups.yahoo.com/group/dmcnews Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/dmcnews/ <*> Your email settings: Individual Email | Traditional <*> To change settings online go to: http://groups.yahoo.com/group/dmcnews/join (Yahoo! ID required) <*> To change settings via email: mailto:dmcnews-digest@xxxxxxxxxxxxxxx mailto:dmcnews-fullfeatured@xxxxxxxxxxxxxxx <*> To unsubscribe from this group, send an email to: dmcnews-unsubscribe@xxxxxxxxxxxxxxx <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/