In Reply to: Re: OK, so where is the thermostat? posted by Wayne McKay on April 06, 2001 at 00:11:34:
The thermostat's only job is to open allowing flow to the radiator around the 85C mark. I think terminology is the issue here, you are likely referring to the Engine Coolant Temperature (ECT) sensor. The ECT sends engine coolant temperature information to the Engine Control Module (ECM). It is located on the coolant cross pipe in the right rear of the engine compartment underneath the coolant reservoir. It is the one of three located furthest from the end of the cross pipe (ie. if the end one is #3, the one you want is #1).
The other cold start information it receives is from the Intake Air Temperature (IAT) sensors located at the back end of each of the intake headers.
As for Motronic 3.1, the '88-'90 DME is v1.2 and '91-'94 is v1.7 for the 5.0L, 12 cyl., M70 engine. The 3.5L, 6 cyl., M30 engine is v1.3 and the 4.0L, 8 cyl., M60 engnie is v3.3.
No lack of 'Alphabet Soup' when you step into one of these beast is there?!! :)
Guess that's why I could not find them. I presumed cold start was handled like my old 528... should have known they'd change the config on the motronic 3.1. I suppose that means that the length of time that the regular injectors are operating in cold start mode is handled by a thermostat somewhere. Any clues as to which one that is?
Correct, no cold start injectors. Normal injectors are held open longer during cold engine conditions.
No such thing as far as I know. Maybe some of the long time DIY'rs might know of something but I think the 'cold start' is handled through the DME with the normal gear.
Can anyone give me a description of the location of the cold start injectors on a V12? Originally I had thought they were on the firewall end of the manifolds, but these are the intake air temperature sensors. Any help?