Gripenfelter

iTrader: (1)

In the last couple of weeks, very randomly, the car will go pig rich like 8.06:1 AFR at idle and throw a P0200 code.

Scanned with HP Tuners and noticed my passenger side O2 sensor also has periods where it blanks out.

O2 harness and wires seem intact and not burnt anywhere.

So do I have a bad O2 or a short in the injector wiring or both?

I'm gonna tear into it this weekend.

jetech

Maybe O2 sensor is dying, doubtful there is a short causing it

Gripenfelter

iTrader: (1)

So here's what I did:

Checked pins 1 and 40 on the PCM harness for continuity. They showed less than 1 ohm of resistance for both red and blue connectors.
Checked injector harness wires and they show 12 volts on the power wire and using a noid light they blink the ground light appropriately.
The passenger side O2 sensor seems to blank out. Swapped in 3 different O2 sensors and have various issues there.
Wiring for passenger side O2 is intact and I verified it with a voltmeter.
The 5 volt low high reference sometimes disappears at the O2.
Swapped PCMs. Still does it.
Used a third set of O2 sensors and it shorted it out after 5 mins and burnt out.

WTF?

I'm ready to throw in the towel and buy a Terminator X kit.

jetech

Can you give us more info, what vehicle,is it factory, modified, swapped?

Gripenfelter

iTrader: (1)

2001 Trans Am.

427 DART block.

Using the factory wiring and harness, etc.

jetech

OK. I would lean towards you being looking in the right direction about a fuel injector/harness issue. I'd be digging around with an ohm meter while moving the harness and connectors. Then i'd check the injectors. Intermittent issues are always a P.I.T.A
Good luck and let us know what you found. When testing issues like these it is best to have the engine at the temperature of when the fault occurs .

Gripenfelter

iTrader: (1)

I took the car to a shop yesterday. They are great at finding issues in regards to shorts and wiring issues.

They can't find anything at all. They've been at it for 7 hrs. They verified that the O2s are out of spec.

They just replaced the O2 sensors with new NTK ones...so far so good.

But the P0200 code hasn't come back for a few days.

If it comes back, I'm gonna have to go Terminator X.

2 PCMs, 3 sets of O2s, checked all injector harnesses, etc. I'll have no choice.

jetech

Gremlins!

Gripenfelter

iTrader: (1)

Found the bastard.

My #8 cylinder connector has 12 volts and the ground but it doesn't stay connected to the injector. It make a clicking sound but only one side is on.

Couldn't see back there but when I pushed on the connector it clicks every time I push on it.

Cut it off and soldered in a new connector. Found the connectors on Amazon.