Tampa 928s

Also I am still getting a random skip but not all the time like before.

Fabio421

Just because you hear a click doesn't mean that it is actually working. Its just a micro switch. Check that it is working properly and also verify that the throttle is making full contact with it when closed. There is an adjustment range for both of the throttle micro switches so that they make contact when at full throttle and at aidle. I'm sure you have probably checked this simple thing, but sometimes the simplest things are overlooked.

Good luck

John Speake

Have you set the idle CO and idle speed according to the WSM ?

Tampa 928s

No I have not, I will check into that Thanks

Tampa 928s

I disconnected the O2 sensor with car warm and at idle looking at my Lm-1 screen on the laptop it read 9.9 -10.2 no matter where I moved the adjustment screw. I did wait between turns a few seconds between adjustments.

John Speake

How much did you turn it ? It is a 20 turn adjuster, so you need to turn at least a couple of turns to have an effect. Turn it anti-clockwise to weaken the mixture.

Tampa 928s

Humm I will try again 20 turns wow !

Tampa 928s

Did the adjustment

With OX disconnected I can get around 11.3 with it connected aroung 13.1 no where near 14.1

Tim Murphy

The WSM says to make the adjustment with the 02 sensor connected. I would also do this with a warm engine otherwise the TempII sensor will be in play.
CCW on the adjust screw for a leaner mixture.

Tampa 928s

I printed out the manual and for C.O. adjustment it says to disconnect Ox sensor, but this was for an 87. Kevin wants me to return it I need to test it a little more first.

John Speake

Page 24-204 of WS manual says clearly disconnect O2 sensor. This is is for 85/86 cars. This forces the O2 loop in the LH ECU to a midrange setting so the O2 can be set correctly.

Do you have fuel pressure set to the correct value ? Good vaccum on the FPR ?

Tampa 928s

I thought so yes FP is fine and Vacuum is a solid 18 at idle.

John Speake

Did CO change at all when you turned the CO pot ? If not, it sounds like somone forgot to refit the coupler inside the MAF between the adjuster spinder and the pot if you can't get any change of CO !

Tampa 928s

John,

After turning it CCW to lean it out a bunch of times I did get to 14.1 A/F with the Ox Sensor hooked up but not with it disconnected it was around 11.3 A/F.
I was using my Wide band hooked to my Lm-1 to observe the A/F ratio not the CO2 level.

John Speake

OK, so it is adjusting. What you are seeing is that the "true" A/F ratio at idle is 11.3 which is pulled by the O2 loop toward stoich of 14.7 by the O2 loop. So the basic A/F ain't right !