First - apologies for the long post - ignore if time is short. Just trying to avoid guesswork from respondents.
Thanks for continuing! I should start with a little into: I bought my 1990 C2 with a 412HP (my Bosch dyno) 3.8L engine (993 RS Evo2 Cams etc..).
The car also weighs 1225kg with Recaros, aircon delete, lightweight flywheel, clutch & exhaust and a LSD - in short quite a nice package
It new to me and I'm no expert so forgive any sillyness below .. I'll say thanks now as there's bound to be some
The RSE (Emulate/Emelia to her friends) has been used almost exclusively as a Auto-X car since 2006 ..
but I want a 50/50 track/road car .. without putting the weight back on.
The only small inhibitor to this is the off-throttle/low rev/idle performance ie for city driving. Yes, the cams aren't ideal
but they're not monstrous (IMO). The car doesn't idle well when cold and even when hot it sometimes (25% of time) drops off
ie below 500 rpm and then stall after its been driven hard and then comes to a stop ie like after exiting the highway. I have to
ease her down and Heel & Toe a bit to let the revs fall less extremely ie doesn't stall is it falls from 1.5k to 800 but does
if it falls from 3k to below 1k. Fun on the track, tiring in town to say the least.
The root issue in my mind is that the ECU has been unattached (see first 4 pics) with the engine/fuel mgmt
outsourced to an aftermarket solution.
dictator - box and wiring.jpg
The engine was built and installed locally 3 years ago by a guy who has now left a Porsche racing workshop to go to Fiat ..
so no support there. Shame for him What he did - PO was cutting costs to some degree - was to use a simple but effective
locally made Fuel Mgmt System (FMS)( made by some ex-VW Germans who now live here.
So instead of piggy backing the system on the 964 Motronic ECU, he sliced off the necessary wires, disconnecting the ECU and thus removing
the ECU and its advanced idle mgmt/cold start etc.. as well as all its fault finding ability.
The 2nd set of pics: FMS with its maps controls the idle with a 4mm vacuum hose that is shown in the first collage attached to the throttle body
via the lower piece of blue silicon. Needless to say its not as clever a system as the motronic. My plans - for which I'd love input please! - is to:
1. rewire the ECU back to standard - intermediary step - to ensure it still works. Luckily I have an ex-Motronic tech here.
2. Use front foot well plug and motronic sofwtare to check the ecu/fault codes etc..Considering the 3.8 there shd be a few.
2b. but the worst of it will be (I think) that I dont seem to have an AFM. I can plug the ISV in and I know it works.
3. The tech will then piggy-back the dictator chip next to the ecu and only take the fuel injector wires etc.. out of the ecu
and use a loom that dictator supply ($50) to do so.
4. This way the ECU shd be able to control the ISV/AFM/idle, be used for fault codes on everything other than the fuel mgmt
... knock sensors, ABS being the two principals I've thought of. I'm sure there are a host of others. ABS does work now, just fault codes not available.
Any other experience or insight into this process would be most appreciate from the various ECU/Idle Jedi out there.
PS - I got all the bits that came off the car and I don't see an AFM and the blue pipe between air filter and TB is clearly not stock.
That's where the AFM should be but I don't have an AFM anymore - will engine run without it when I do steps 1,2?
Addition: Seems I shd be fine without the AFM for the intermediate steps
dictator setup collage.jpg