Misfire = No Power, Timing Stuck at 25 BTDC and Stuck in Open Loop

[doubleclutch]

So on the way home today my car began missing and sounds ike it dropped a cylinder. If i shut the car off and restarted it went away briefly and then came right back. I have a freshly repaired ECU from ECMtuning and I do not have the CrankAS inverted. I have had this problem on a 98 ECU (my car is a 98) as well as the freshly repaired 95 EPROM i just got back a week ago.

I don't have link yet but the bluetooth transmitter and phone app i use showed 25* BTDC timing and it would only move from around 23-27*. It also stated that the engine was in open loop due to engine load or decceleration. Everything else looked normal. Tach did jump around a bit. Engine seemed to have gotten pretty hot in all this mess although temp gauge never moved.

Any ideas?

 

[Soccerguy136]

That's quite a bit of timing advance, but it could be because the ECU is trying to accommodate for something else that is wrong.

Is the check engine light on? If it is, what code is being thrown?

 

[snowborder714]

Never heard of a car going into open loop for those reason. It might just be a more friendly version of one of the items listed in this link.
fueltrimupdatepoints [ECMTuning - wiki]

My guess with the '95 ECU is the CAS signal difference and that's causing the issues. When you swap to a '95 ECU on a non-'95 CAS sensor, you need to swap the plug wires and invert the CAS signal using link.
swapplugwires [ECMTuning - wiki]

Do you plan on getting link soon?

 

[doubleclutch]

TI is throwing a P0300 (Random misfire) and a short term fuel trim p0141 i think.

The plug wires are swapped but the sensor is not inverted. I had similar issues on my 98 ECU so I am not sure it is really an ECU swap issue.

It could be due t the O2 sensor. I really need to pickup link because I am only using Torque (free) (phone app) and a blue tooth transmitter but it shows no very little O2 senosr movement (randomly spikes to .4 or so). That being said I drove it like that for over a week and a half with no issues.

 

[doubleclutch]

Did some more trouble shooting today.

Warmed the car up (car refuses to misbehave at idle unless it was already misbehaving) and took it for a drive sure enough same problem within 2 mins of driving. Cyl 2 again. swapped wires 2 and 1 and went out again. Same problem except now it is cylinder 3. Swapped wires back. Took it out a third time. Stayed at cylinder 3... WTF?

Thoroughly confused now. Although i think I can rule out wires and plugs at this point.

I also unplugged the Cam AS as the car was running poorly. Did nothing, no change. Plugged it back in and the revs dropped for a second and then back to no change.

Both scan tools I used said it was "OPEN loop for engine load or decceleration" although the one calculates engine load and it was no different than it was before it started acting up.

Timing seems to be dead on. Checked it via the crank pulley.

 

[doubleclutch]

SO i pulled the CamAS today and set it 180 degrees out of time. (I believe this is the mechanical equivalent of clicking the "invert CAS" in link). Car fired right up, seemed to run fine. Took it for a spin and I had no issues. No backfire during pulls, hesitation, or anything else. It did not drop a cylinder.

So either it is resolved or it just decided to behave today.

Can anyone verify that installing the CAS 180 degrees out of phase is the smae as inverting it through link?

Thanks

 

[snowborder714]

Can anyone verify that installing the CAS 180 degrees out of phase is the smae as inverting it through link?

No, it's not.