Tried running on the stock injectors and ECU this morning. It cranked but the AFR would not maintain at 14.7, it hovers around 13.0 or so. If I give it any gas at all it bogs and AFR drops even more. Looks like there is some other problem.

I am wondering if a failed OEM O2 sensor could cause this. I got a CEL P0132 "O2 sensor circuit high voltage (bank 1 sensor 1)" last Monday.

 

I replaced the O2 sensor but the problem remains. My wideband started working again and it says AFR settles in around 13.8. If I give it even a little gas the AFR drops and the engine bogs.

Not sure what to look for next.

 

Can you let the car run for more than a few seconds now?

No more fuel dripping from the test pipe?

 

I took the SC belt off, disconnected the 5th injector, disconnected the ULT. The car will idle and after searching a bit will settle at 14.7 AFR. If I give it any gas at all the AFR drops to 10 or so and it bogs down badly.

Reattached the ULT to try to log some data. The car cranked but bogged and cut off almost immediately.

Disconnected the ULT again and the car cranked and idled like before.

I can idle the car for several minutes and maintain normal AFR (no gas dripping off exhaust).

 

You disconnected the ULT and still ran rich because you have the 550 installed that is expected.


Connect your laptop up to the ult and up load your map to the computer.

Save the file to a new file name then before.

Turn off the car.

Turn car back on

Upload the just saves map back into the ULT over righting the old one.

Turn car off for 20sec then try starting the car.

Had the same problem you are having this morning after slightly changing a map.

When I re-uploaded the same maps problem when away.

The maps are identical however have diff file names have not had a problem since.

 

Chris came over last night and checked out my car. Since it would idle now, he could get more data with his diagnostic tool.

I had already put the OEM injectors in, disconnected the ULT and 5th injector, and removed the SC belt. So it is set up as stock.

I thought it would bog when given gas, but it actually would rev up. I guess I was being too cautious. AFR eventually stabilized at 14.7.

TPS and map sensors checked OK. Fuel pressure was a little high at 50 psi (Walbro 255) but not high enough to cause a problem. The primary O2 sensor that I replaced Sunday was not reading/reacting properly. The fuel trims were off also. CEL came on eventually due to the fuel trim.

Chris thought that gas may have gotten into the engine oil, and that the fumes might throw off the O2 sensor. I drained the oil and it reeked of gas. I put in new oil/filter and when restarted the O2 sensor and trim were much better although not quite at the ideal level.

I drove the car to work this morning with no problems. In a couple of days I plan to change the oil again and have Chris recheck the O2 sensor and fuel trim.

A couple of ideas on what caused the original problem:
1. One or more of the 550 injectors stuck open. Need to send these back to the supplier for testing.
2. The original O2 sensor went bad due to to much low AFR. However, this does not explain why No.1 cylinder got so much more fuel than the others.

 

good to hear

 

Made it back home from work this evening without blowing up. That's a good thing! Unfortunately my wideband sensor is dying a slow death, probably from drowning in gasoline. Easy enough to replace, just mo money.

 

No CEL I take it?

 

No CEL yet. Got my fingers crossed. Wideband came back to life this morning.