cold start

[jonc3725]

My Thermotime switch has gone duff which means the car starts but runs like a bag of spanners until the coolant temp rises. I have tried all the suppliers (including Jaguar) and no one supplies this part at the moment.

The switch is the same on all pre 86 3.6's and and all V12's up to 89 I think. I know land rover used the same switch as well but I don't have the information from Lucas to find out which ones use the switch. Does anybody have a spare (Good) one in their garage I can buy as even second hand they seem to be like Rockin Horse S**t.

thankyou in advance to anyone who can help

[almcl]

The thermotime switch is only activated for a short period when the ignition key is in the start position. It keeps the cold start injector(s) on for a maximum of 12 seconds when the temp is -30°C or below. At higher temperatures it is on for less time, until at 35°C (coolant temperature) it is completely inactive.

If your engine is running badly after starting something else is amiss and changing the switch won't fix it. Martin Robey list a re-manufactured version of the switch at £72, if yours needs replacement but if it were mine I'd fix the other problem first.

[jonc3725]

No it's defo the switch. I have swung through it (in accordance with the maint manual) and it's way out. If I remember rightly it finishes switching at 36 degrees C coolant temp but it's not operating at all. Even with coolant temp of 20 degrees the cold start should operate for a couple of seconds but there is no fuel from the cold start injector at all. As soon as the the temp of the engine rises she runs as smooth as a babies bum although I need to change the throttle pot this winter.

I didn'y realise Martin Robey had re manufactured ones I will give them a try, thanks

[almcl]

While I agree it certainly sounds like there's something wrong in the cold start circuit, I still don't think it's the cause of rough running/poor engine response after start. However, I have been wrong a lot of times before!

Post back if you get the cold start injector working and let us know the results?

Could be that I/we will all learn a bit more?