As per the other thread, i've various running issues that i'm trying to resolve. If i'm going to replace parts, i tend to buy new, as then i know i can rule it out. However the MAF's are ludicrous money, so i've got a used one.
So i'm wondering if i can send my MAF to someone on here with a GEMS car that actually works, and swap it in and see if the MAF is actually working properly. That way i can rule it out as a possible issue!
Cheers.
I would, but mine runs as rich as a rich thing on petrol idle. It's OK once it clears its throat but that won't help you.
I'm on Tornado chips, single point lpg and start and run it only on lpg so the petrol just happily circulates from the tank to the motor and back again.
When I get bored and fancy a fiddle, I've swapped lambda's and looms, MAFs, ECUs and I still get 7 volts out of my Titanias (theoretically impossible!).
Actually, I'm not sure if there's anyone on here with a GEMS that's running cleanly on petrol. Let's see...
Have you checked the voltage at idle (yeah, I know you're struggling to get it to idle) from the MAF at the ECU?
Should be 1.4v at pin 16 (UG) on the large connector
ive viewed the voltage and airflow with nanocom, and it seemed "sane".
At 2500rpm it gives the 60g/sec specified in the manual, What happens if i try to back the revs off though is peculiar. I can get it down to about 2000rpm. Once there, a tiny reduction in throttle will cause the RPM to fall, but then keep falling. I presume it gets too lean, which causes the engine to slow down, which causes it to get leaner, and it goes into a spiral that if left unchecked would result in a stall. To catch it you add a tiny bit more throttle, and it revs right back up to 2500rpm again.
So i THINK the MAF is fine. When it idled properly, before i started messing with the injectors, i'm sure it sat around 20g/sec at idle
From listening to the engine, it seems that the vacuum leak gets larger as the engine slows down, so i guess this makes sense, as more air will be coming in via the leak rather than via the MAF.
Oddly it still does this trait with the maf unplugged as well, but its easier to control and you can with very fine throttle control get it down to idle and it will then sit there.
You're not going to get accurate fuelling with a vac leak, even if everything else is perfect. I'd try and fix that first and revisit the MAF if necessary.