Ok, well, I finally got a chance to give it a drive. this time completely with the O2 disconnected. (but I still had the narrow band gauge connected to the O2)

on initial start a/f was steady at 13.8, slowly climbed to 14.2 as it warmed and pretty much stayed in that area. Took it for a drive. At first backing out of the garage, it was dipping to 11s, and I was thinking "oh man, no...!" but then as I started to drive it started to stabilize from high 12s to mid 13s, gave it a few brief boosted runs, and richest was about 12 (disconnected the Vac line for the boost enrichment)
and the NB gauge seemed to coincide with the WB, I actually think now its a good idea to have both. If things are tuned right the NB is still giving usable info, and you can see what the "computer/abacus" is seeing.
So while not perfect, definitely much better and driveable.

so you removed the vac line to the WUR so it would NOT go rich on boost?
and you were still in the 12's?
you have an air leak on the pressure side.

yeah, thats exaclty what I wanted, what did you expect? would dip into the 9's on boost and bog down previously.
Feeling a stronger pull on boost now.

but you still have something wrong.
and its on the pressure side.

Also, narrow band sensors don't really give useful output much either side of stoich.

well I can't find any leak, so heres the latest update. as mentioned previously when I took it for a drive with the O2 disconeccted it ran better, at least it was driveable. But I only drove it around the neighbor hood, with out shutting off.
So everything described from now on is with the O2 disconnected.

Tonight I drove two places, let the car sit for a couple hours at my friends house, then to the grocery store. So the car was good and warmed by the time I got to each.

But heres where I noticed something strange. When starting the car again. it would be very lean, 18-20A/F for a few minutes, but after it "warmed" up (even though it was already warm) it started running "ok"
Finally when i got home, I let it sit for about 30min, then tried to start it again. Same thing: slightly hard to start and once started it was very lean, for about 3-4 min, then all of a sudden it went back to "normal". What things would change after a few minutes of running? Thought maybe the AUX air valve?

pull the connector off the top of the AFM so the FP runs all the time.

turn key on for a few seconds before starting and see if anything changes.

Have you actually checked the AAV? They can go bad. I could imagine where the car is cooling down and it will slowly open - letting more air bypass in to the intake. Then after a few minutes driving it will close that down - as it should. But it could be out of whack as far as the setting goes. You can look down the neck and see the slotted disc with a torch/mirror. When cold there should be an appreciable slot open. When hot, it should be fully closed. It is a rotating disc with a slot cut in it, and it moves via a bimetallic finger - very similar to WUR warm up system.
Alan

Well, I actually did check the AAV previously when I was first having trouble (with the A/F fluctuating, replacing the O2 solved that) also put it in the freezer to check it.

BUT!:confused: Now that I think about it, I don't think it would make for a lean condition as doesnt it only by pass the throttle?? not let in any outside air? or am I wrong?

also BTW, I tried turning on the Fuel pump before the "hot start", as I know I have a little leak back into the tank. I can hear the injectors squeal for a second, when I do.
But I don't think that made much difference still to a long crank to start. then I got a plume of smoke when it did, assuming too much fuel.

But normally I will turn the key let the fuel pump do its "prime" then crank.

the AAV raises the idle when cold by bypassing air around the throttle plate but the air is STILL metered by the AFM and wont change the mixture.

yeah, thats what I thought, so I doubt that's it.

what else changes after a couple minutes of running??

only the control pressure. it goes UP to lean it out.

you should be open loop all the time if your O2 is not connected.
not sure where you would goto check the duty cycle of the freq valve (FV) to see if it changes after starting.

maybe look at fuel pressures,
maybe a check valve is bad.(i assume it has one).

i know on my 930 when i do a hot/warm start if i get on it too soon it can fall on its face, but only right after starting up. i want to say it did this with the old FD and the new one.
i noticed it first at the track, then a few times around town.
i am thinking its something fuel related, kind of like a vapor lock.
i dont worry about it as it does not happen much.

My AAV worked well the issue a smoke test revealed was it's molded rubber plumbing leaked air.

I removed it (actually a nice weight savings) and had no issues cold starting in January.

My all steel 930 backdate weighs 2150 lbs with 6 gallons of fuel, fire extinguisher, tool kit and lead acid battery.

Matt

One more item to check would be the piston in the fuel distributor might need to be very gently cleaned.

I’ve read many posts where the op has stated completed testing … only to find out days later that when the actual test results are posted the numbers were out of spec. I sure you have not done this but specific test results might just help our local experts.

Rahl


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