Hi all, new member here.
I have a 1989/90 VW Passat Variant GT 2.0 16V with a 9A in it.
White label in the back says (100kw) GKAT 9A, (etc.), so guess it's the correct engine for the car.
Now, my problem is fuel economy, which is 23.5mpg, no matter what I do.
This is according to actual volume "fed" to the tank and odometer reading, NOT the weird MFA...
I have a good deal of experience jetting both EFI and carburetted car/MC engines with my Innovate LM-2, and have done so with this car too.
It runs stoich at part throttle(14.7'ish), and about 13:1 at WOT.
Compression is measured to 16 bars(232psi) on all 4 cyls.
Ignition is at the mark ( the line, not 0) at idle when I strobe it, and is not more bouncy than any other stuff I've strobed.
Now, I found a double connector alongside a single, male, yellowish connector at the passenger side, in the engine compartment, at the firewall.
They are NOT connected to anything, but there seems to be 15'ish volts between the poles in the double connector, and 500mV'ish + in the yellow thing.
There's no cat nor lambda in the car....not even an M18x1.5 bung.
Won't the ecu go into limp mode, if it lacks the lambda, and switch to a very non-economic fuel- and ignitionmap?
Of course, I have compensated for that fuelmap, by adjusting the co-screw and the electrical valve thingy on the side of the metering head, but won't it still run a less than optimal ignitionmap? (thinking the reason for bad economy here)
Car is very touchy on that CO screw and idle, I can adjust those like every week.....
I've hooked the LM-2 to the 4-gas tube that sits on the ex manifold with a special adapter I made, cause I can't reach the exhaust under the car, when it sits in the driveway....
Plugs are tan
So, is the ECU running in limp mode, making the car use too much gas?
What do I do, install a lambda eliminator, or install a new lambda in the exhaust, and recalibrate?
Regards, Rookie, Denmark.