LBA50

Scanner shows the following codes:
P1371 - "Distributorless ignition low resolution circuit"
PO174 - "Bank 2 System Too Lean"
PO151 - "Oxygen Sensor Circuit Low Voltage Bank 2 sensor 1"

'96 Vette has given me problems for a few months now. Some days runs fine, others the engine cuts off in traffic for no reason. Has not thrown code before now.

Fuel pump nearly new. Opti-spark, new plugs & wires about a year ago. All wires/connections checked about two months ago with stalls and occasional rough running started.

Now these codes -- FINALLY! What do they point to?

antfarmer2

I would clean and check connections again and blow smoke in the vacumme system to find vacumme leaks. clean throttle body and iac. maybe have your coil and icm tested. clean and check connections and ground on the icm.

LBA50

A vacuum leak would cause those? I was thinking an oxygen sensor had gone bad and maybe the Opti-Spark harness was loose (or bad).
But thanks-- I'm looking for things to check and I appreciate your input.

93Rubie

Can your scanner show live data?

What is the 02 sensor reading? At idle, cruise, on the throttle but NOT WOT. Does it switch rich to lean? How fast?

It is VERY plausible that the car is running lean and throwing the Lean code AND the Opti-Spark code. Think about what is happening. It only sees the Low resolution signal so often so if the car is cutting out.....it may not see it enough and throw the code.

To test the 02, you can create a lean condition (if it is not already) or a rich condition. Propane or some carb cleaner shot into the intake will do this. FYI, you need a propane injector tool or you will NOT get enough flow from a can of it to effect the engine. A blow torch unlit is NOT enough. Do this BEFORE the MAF sensor.

You can clean crap and **** around with it or you can actually diagnose it.
A lean condition can be caused by a vacuum leak but don't you want to see if your adjustment tool (02 sensor) for your a/f ratio is working?

You should also test the MAF sensor as well. What are its readings at idle, wot? In g/sec and voltage helps. Even better if its in Hz. Has it been cleaned? Is it contaminated?

LBA50

All good ideas. My scanner only works with the ignition on, but engine not running. So I'm limited in some of these tests. May have to take this to the shop and see what they can find.
Thanks for your suggestions.