Yes, with the adjustable one, I could set it to what ever pressure. and it made no difference. The WUR isnt that complicated, so Im trying to think of what could go bad on it. the O-ring and the metal diaphragm looked good.

Dont know how it relates to your throttle/AFR issue - my head hurts thinking about it. But you should not have that much pressure in the WUR. Is you return line working OK?
Alan

Well, I guess im not sure that the return line is working ok?

I do have the valve I can close to check System pressure, and that gets about 85psi.
(actually BTW, I found I could quickly "lean" out the fuel, by using the valve to reduce flow, easily see if it was too rich, but that probably doesn't mean anything here)

But thats what gets me, no matter how I lean it out, it still spikes rich.:confused:

what other way could more fuel get put into the system?

Ok I put another WUR in (also adjustable) set the cold non running pressure.

initial start up was 11.5, once it warmed up went to 14.5, vac at -10. I got in and tried it again, as the RPM got to 2k the A/F moved to 10.5.

its like the enrichment curve is too steep.

you could put air pressure into your WUR to when it goes rich. thats the only thing i can think of WUR related.


i had an issue for a VERY long time that turned out to be a bad FD. even after being rebuilt..twice.
i did LOTS of testing.
it really sounds like you have an air leak on the pressure side.
even parked, reving it will make the mixture go rich,

just curious, is your BOV vented to atmosphere or recirc.

also, what year is the car.

well... maybe a clue?
I talked to a local shop... and he mentioned how I should set the idle A/F with the O2 disconnected.

So I did that. initial start ut was at 11.6, where is pretty much stayed. so I adjusted at the distributor/meter to 14.5.
Now when I rev the engine it only goes to 12.5 (in the garage, havent driven yet).

So what does that say?? couldnt burn out a new o2 sensor in 20 miles could I?

From memory, it is supposed to drop a bit as you apply throttle.
Your leanest numbers will /should be on a trailing/light throttle. They have a bad habit of running very lean then - 15s not unusual.
As you apply throttle it should drop. But not to boost dump numbers -until the WUR sees boost pressure. I am not familiar with the lamda loop so can't help on that.
Alan

i didnt see, did you ever check control pressures

yes, I set the cold pressure at 38.

the BOV is recirc

was doing a bit of reading on o2 sensors, saying the need outside refernce air, amont other things.... so I decided to get under and have a look just to see whats what.
and I find the outside of the sensor is covered in oil. oil seems to be leaking right on to it. and the end where the wire goes in, has drops of oil on it (rather than just a thin coating.) could oil have gotten IN TO the sensor??

I pulled out the sensor it has a coating of soot on it, but I assume that from running rich, im sure there is slight oil burn, but it can't be bad enough to kill a new sensor in less than 50 miles.

https://cimg2.ibsrv.net/gimg/rennlis...7e0cbfcdab.jpg

interesting idea:
https://www.benzworld.org/threads/oxygen-sensor-mod-for-single-wire-sensors.2189458/

Hrmmmmm, I just tested the o2 sensor, by putting a volt meter to it and using a torch. don't know about the accuracy, but it did show up to .9v got the tip red hot.

same with the old (previsou o2) show a .87 volt reading. so I don't know what to think now. (the previous one only had about 200mi on it)

I ordered a new one, this time a walker brand (supposedly made by denso or NTK) (only $15) instead of the 2 bosch.

I cut the wire from the O2 to the computer and put in connector so I dont have to climb under the car to disconnect it, and I think Im going to temporarily install an old "narrow band" A/F meter direct to the O2 wire so I can see what it shows. Im assuming the Wide band and the Narrow band should be somewhat in sync.



Oyyyy!

Did you solve your problem already?

I had issue with really rich a/f while ago (at the same time idle was high) After troubleshooting i noted that engine runs fine with just one fuel pump, only it runs very rich.

Problem was bad connection on fp relay, once that fixed, idle returned to normal (fp relay feeds also aux air valve) and mixtures returned back to normal.

Maybe one of your pumps are not running or not creating pressure?

Bad fuel pump will manifest with low system pressure. Idle and cruise will be rich, boost will be very lean.

The Lambda system must be taken out of the equation. Unplug and remove the O2 sensor then adjust the idle mixture to ~13.5 AFR at idle. Check AFR and FP at idle then under light engine load. It should drop to mid-12's light acceleration as vacuum drops then pop up to around mid 14's at cruise.

Finally got a chance to play around with it more.
So I got a new o2 sensor.
But first I hooked up the Narrow band o2 gauge and put a connector in line so i could disconnect the O2 easier.

First I put the "current" o2 sensor back in to see what the Narror Band showed.
once warmed (pressures and A/F set) the NB started dancing back and forth.


NEXT I installed the NEW O2. and heres what I noticed: Started the car, with o2 Disconnected to set the A/F... seems ok, rev the engine, seems normal, (needs some adjustment, but a lot more normal than previously) Connect the the O2, A/F start to go lean towards 16+:mad:

Unless you need it for some sort of emissions test then I don't see the value in messing with it. The O2 sensor on the CIS Lambda engines only provided closed loop control at idle when at operating temp. I don't remember exactly where the cutoff was, 1,500 rpm maybe? but beyond that the lambda circuit is disabled.

Disable it, but leave the valve powered/connected. Adjust your idle mixture and airflow to get the 850 +/- 50 rpm with an AFR the engine likes, probably somewhere in the mid-13's, and be done with it.

Once that's done, if you have mixture issues at anywhere other than idle, the problem lies somewhere else. Could be your system or control pressures are off, you WUR isn't working or is the wrong type, leaking vacuum lines, pierburg switches not operating correctly, air leaks in or out of the intake system under different loads, there's a million reasons.

i believe it was closed loop up to around 3500.

then open

mmmm....maybe, don't remember the deets. Certainly wasn't full range or in boost.

yea, on the circuit diagram it has either 3500 or 4500 on the speed rly
that sends a signal to go open loop.
pretty sure 3500

the speed rly is known for bad solder joints.
hitting them with a soldering iron can fix some running issues.