Hi everyone! I'm currently trying to put my freshly restored 95 Spi back on the road but after days of troubleshooting and just cannot pinpoint what's wrong with it... So I'd love to get some help from all the injection gurus from here!
Engine is freshly rebuilt and so is pretty much everything on the car but I'm experiencing some starting and idling issues. To help with the troubleshooting I've sorted out a fault reading setup with memsFCR and will try to give as much data as possible.
From cold, it takes quite some cranking to eventually get it to sputter and it needs to be revved a bit not to stall on and after the initial cold startup.
Eventually (after some light rev helping) it will idle rather roughly at around 1300rpm and IACV at around 60-65 steps. If I let it warm up (reaching 85-88°c), the revs will lightly drop at around 1200rpm and the IACV @ around 49 steps. Idle at this stage is high but stable.
MAP at idle 26-30kPa - lambda between 200-700mV - STFT between 26 and 29
If I kill the engine and try to restart it at this point it will start a lot easier than cold but will still need to be helped not to stall initially.
When fully warmed up (88-90°c) if I either try to adjust the IACV (which sits at 49 and doesn't move anymore unless given some throttle) or give it some revs (to which the engine responds very nicely) the IACV just drops straight to 0. Idle drops a bit too, engine struggles and eventually stalls if I don't maintain some rpms.
MAP still at around 25-26kPa - lambda 200-700mV - loop is closed - STFT around 23-26
Now at this stage, if I "trick" it into staying at a fixed 35 steps with the memsFCR, it idles fine at around 900rpm, no faults, everything going steady...
But obviously once I disconnect the FCR and let the ECU deal with the IACV it drops straight back to 0 and stalls again.
I've checked the IACV operation and coils resistance values and everything seems fine, I've tried and tested some different IACV units as well but it does the same thing.
I've also checked the throttle position sensor, resistance values are also spot on and also does the same thing with some different 2nd hand sensors (tested too)
Tried swapping the crankshaft position sensor as well, doesn't help.
Checked the ignition coil and swapped it, doesn't help.
Fuel pump is priming and can be heard when the car is running.
Oxygen sensor is brand new and the heater relay clicks fine.
I've checked every hose and vac line (most of them are new anyways), plugging some etc and it doesn't change either
Oh and I've taken the car out for a couple of short spins when the idle is stuck @1300rpm and 49 steps (that way it doesn't stall) and the engine pulls nicely through the rev range. It's really just that idle and cold/hot starting issue.
Any help or direction would be incredibly appreciated...
