Went to the track... highly disappointed, and found a major problem.

[jetjock]

Ah ok, I see. It should work to display Vf then. Try measuring Vf at the diag block (using your DMM) with the WB user input disconnected and then connected. If it pulls Vf down when you connect it something is wrong inside the WB controller.

The propane trick will give you a pretty good idea if the sensor is good but not 100%. It won't tell you if the switching point has shifted. That probelm is very rare though.

You can also use propane to do artificial enrichment. It's the opposite of pulling a vacuum line off. In fact they're are propane enrichment tools sold just for this purpose but a hose shoved over the torch works. Introduce the propane into the manifold while watching the O2 sensor signal. Enough propane will drive it rich (about 800mv to 1 volt).

Pull the booster line off to drive it lean. Vf should also respond. Again, this doesn't tell you the sensor's switching point is correct but it will verify closed loop is working. If you had a scope you could also monitor injection duration and watch it change.

 

[Doward]

Vf remains @ 2.21v NB-sim connected or disconnected while idling.

Vf remains @ 2.21v NB-sim connected + vacuum line off while idling.

Measured @ Diag block

 

[Doward]

Here's a weird bit of knowledge... I pulled the NB-sim wire, and measured the voltage while the car was running. It was dancing all over the place, between 0-1v, and would periodically hit 450mV.

It would only do this, though, when I put the red lead on the NB-sim wire, and the black lead grounded to the door hinge.

Get this, though - if I ground to the forwardmost screw holding the ECM in place (where I have the ZT-2 system grounded) I maintain a steady 5.62 volts from the NB-sim!

 

[jetjock]

I dunno...something is goofy there. That aside, you were asking about the 0-5 volt user input, not the sim input. I'd get that WB controller checked out. Again, imho you should install another bung and use the WB only to monitor. Leave AF compensation to the stock O2 sensor.

 

[Doward]

I'm going to put the stock O2 I pulled in there, after I find my propane torch and give her a test.

I'm also going to go over the TSRM for now, see what threads I can pull out of this knot...

 

[jetjock]

Stick with it. I know you're trying and that's good. It's a learning experiment. We can't do much from afar and it also helps a great deal to have the right test gear but there are usally ways to compensate for that. You just have to think harder

 

[Doward]

Ok, following the TSRM's wonderful little O2 sensor (FI-101)

Put a spindle nut behind the throttle linkage, held just over 2500rpm nicely.

Waited 90 seconds

Shorted T and E1, while maintaining 2500rpm

Checked for fluctuation between Vf and E1 - nada. Nothing. Zilch.

Proceeded down course number 3 in the TSRM

Read and Record Diagnostic codes. All I got was a code 51.

Unshorted T and E1

Measured Vf and E1

Now, at this point the TSRM says I should have 0 or 5v. I have 2.21v again! So yeah... no idea where I'm going now! This is with the STOCK O2 sensor!

 

[cjsupra90]

Wait, you said that you are getting 5.62 volts from the NB-sim. thats a problem there in itself being that that is a 0-1v circuit. I would change the all the ZT-2 grounds to a different location, sound like you are picking up electrical niose from the something.

On another note, dont really know to much about the ZT-2 units, but is the a free air calibration for the sensor? if so, when was the last time that you have done it? WBO2's normally need to be free air calibrated periodically to keep there accuracy

 

[Doward]

Hmm... I don't know anything about calibrating the WB02... I'll search on that. Yeah, I'm thinking of moving my ground somewhere else, as well... but that really wouldn't explain the Vf problem I'm having, would it?

 

[cjsupra90]

well not exactly, but an incorrect reading from the o2 can cause a incorrect Vf reading. so it possible

 

[cjsupra90]

I am beginning to wonder if there is actually a mechanical issue like a stuck open injector or something and its not electrical at all.

 

[cjsupra90]

one other thing, check the resistance on the CTS and make sure that it is inbetween 4k and 8k ohms with the engine at operating temp. if its not somewhere in that range, then thats a problem also

 

[cjsupra90]

one other thing about the ZT-2, make sure that the switch point in the softwear has not been changed. I just remembered that the switch point is changable on the ZT-2 to swing the closed loop control from the ECU rich or lean.

 

[jetjock]

You're confusing yourself. Read the procedure carefully.

 

[Doward]

Well, I just went and did the full 'Ohm test' on FI-107 of the TSRM, and this is what I found out -

IDL -> E2 reads infinite when Throttle Open (Good)
IDL -> E2 reads 33.9 ohms (Spec is < 2.3K, so Good)
VTA -> E2 reads 2.5K when fully open (Spec is 3.5K - 10.3k, so I'm going to test out a couple others I have here)
VTA -> E2 reads 674ohms when fully closed (Spec is 0.3K - 6.3K, so Good)
Vc -> E2 reads 1.92K (Spec says 10k - 15k ohm)
E2 -> Vc reads 1.98k (Spec says 5k - 10k ohm)
E2 -> Ks reads 2.82 Mohms (should be 5k - 10k ohm)
Ks-> E2 reads infinite - checks out Good
THW -> E2 reads 327 with coolant fully warm (Spec is 200-400, so Good - which I expect, it is new!)
G1 -> G- reads 287 ohms (Spec says 140-180 ohm)
G2 -> G- reads 284 ohms (Spec says 140-180 ohm)
Ne -> G- reads 277 ohms (Spec says 140-180 ohm)
HAC -> E2 reads 2710 ohms (Spec says 2900-4200)

ugh... Vc is AFM related, isn't it?

JJ, I've pulled the ZT-2 totally out of the equation. Like you said, easier to diagnose when it is all stock I've got a stock O2 in there, but I can't test it propane style... I'm out of propane!

So according to the test I did on the stock O2... I'm getting no feedback?

 

[jetjock]

So now we're screwing with the TPS and AFM? I'm getting confused...

 

[cjsupra90]

Yeah, Vc is both AFM and TPS.

All the G ones like G- and G1 and so on, dont worry to much about those. They are the pickup coils in the CPS and they will have nothing to do with the problem that you are having. Mine were all in the 500 and 600 ohm range before i went full stand alone and never had any sort of problems.

Looking back a the schamatic for the Vc, any resistance issue would come from the TPS, not the AFM.

 

[Doward]

Vf -> E2 stays @ 2.21v while idling. It doesn't move.

If I increase RPMS to 2000+ (quickly, or slowly) Vf will blink at 2.20 or 2.22, but always sits back at 2.21v.

If I let go of the throttle, and let it snap shut, Vf changes downward quicker than I can keep up then hits 2.21v again.

JJ, I'm just trying to pinpoint what the problem is. So far, I don't know if I'm looking at O2 problem, ECU problem, or wiring problem. :3d_frown:

Suggestions?

 

[cjsupra90]

back probe OX at the ecu and make sure that you are getting voltage from the o2 at the ecu and make sure that it is very close if not the same as the voltage at the o2 itself. its seeming like the ECU is staying in open loop

damn, to bad gainsville wasn't 2 to 2.5 hours away or I would take a ride up there and give you a hand.

 

[Doward]

Are you south of G'ville? I'll be hitting up Wildwood sometime tomorrow (guy down there owes me some $$ and I'm collectin' to get my 3" elbow with a spare bung )

Going to check the OX @ ECU in a min.