The ACR4 *does* adjust the stepper - i used one for years and it worked a treat... though you have to use the right pod... Rover 3 IIRC.
ACT will do the same job as the ACR4 for the SPi... not sure on the functionality of the ACT on MPis.
Though both are now EOL products... there seems to be more pods and harnesses available for the ACR than the ACT.. so depends what you want out of your investment. if its only SPi minis then both tools will do the same job...
It DOES require the engine to be warmed up first, correct?
Correct - engine must be up to temperature..
I haven't used it in a while, and my temp sender's toast. I can't get it to pass the waiting for engine to warm up stage..
You will also then be experiencing other running issues... sort the temp sender out.. its quite a vital sensor on these... (it could also be a blockage in the pipework causing a low reading..
hth,
Dave
Edited by icklemini, 22 August 2010 - 11:55 AM.