generaldave

Before we did the exhaust, it had BBK shorties, y-pipe, mufflers, dumped in front of rear axle, no cat. It was such a cobbled mess that it was leaking like crazy, so we redid it.

It did have only one side hooked up. The wire was cut, but the connector on the o2 sensor is there. It ran fine. Drove it an hour to the lake and an hour back no problem aside from dying from the fumes.

We've checked wires, not plugs. I will add that and re-tightening the header bolts to the list.

As for the Scan9495 thing, I ordered the make-it-yourself cords for it. Projected delivery is up to two weeks from now.

Thank you.
~Dave

generaldave

Update...

We did the heated o2 sensor conversion. The car seemed to have ran fine longer than normal. Very smooth idle. Etc. Backed it out of the garage and it started sputtering again.

I should have the cords for Scan9495 today and assembled/set up tomorrow. I'll try to get that thing going asap.

Thank you.
~Dave

Injuneer

Did it run fine for about 206 seconds after the start, and then go bad? That's the time out for the transition from open loop to closed loop. Reset PCM by pulling the "PCM BAT" fuse for 30 seconds. See if it repeats the above performance.

generaldave

206 seconds is probably about right, yeah. We didn't really time it. Just seemed longer.

We pulled the battery cable for 10 minutes thinking it'd reset the computer. I will try pulling the PCM BAT fuse next time I am over there.

Thank you.
~Dave

Injuneer

If you can tie it directly to the transition from closed loop to open loop, it's going to point to O2 sensor problems, or something producing a serious "false lean" or "false rich" condition.

generaldave

Finally got the cables in to make the cable for Scan9495. Reset the computer by pulling the fuse as suggested. Hooked up Scan9495. Car ran for about 2 minutes before I clicked scan because I failed on that one. Instead of sputter this time, the car just stalled out. Ran for 5.5 minutes before stalling. Here are images from the scan as well as the log file.









Link to log: http://www.mediafire.com/view/usclwd...21-085451-.csv




Thank you.
~Dave

Injuneer

Quick look shows:

-is not going into closed loop at any time

-both O2 sensors ar stuck at the maximum possible value, indicating an extremely rich condition or short to a voltage source. Are you sure you have the heated O2 sensor conversion wired right? Does it still smell of fuel when it's running?

-coolant temp never goes above 131*F and both fans are running. The screen shot indicates fan 1 was activated by low oil temp, but there is no oil temp sensor on an F-Body LT1. There is one on a Corvette LT1. Does the car have a manual fan switch added? Are you running a thermostat? Low coolant temp can cause it to run rich.

generaldave

I used these two links to assist the heated o2 sensor conversion:


Diagram: http://shbox.com/1/heatedsensor2.jpg
How to: http://www.fastbirdperf.com/93-97f-b...Directions.doc


I can check the wiring again, but I'm pretty positive I did it right. No, I don't smell fuel when it's running.


I have no idea about the manual fan switch. If it is there, a previous owner put it there. I also have not checked to see if the thermostat is there.


Sounds like I have a list of things to check out.


Thank you.
~Dave

generaldave

I don't see a manual fan switch hidden anywhere and I have not rechecked the wiring on the o2 sensors yet, but I got some new symptoms....

I opened the radiator cap to start the car and see if the water flowed or not, thinking that that would let me know the status of the thermostat. It was about a quarter of a radiator low.

I refilled the radiator until all the air bubbles were gone. Started the car again. The car sucked down about a quarter of the radiator of water and stalled out. I have no idea where that water went.

Thinking the engine may not have been full (and the thermostat was either stuck open or non-existent) I refilled the car to try it again. The car sucked it down a quarter and stalled again.

I decided to see if it was throwing any new engine codes. It now has code 16 (Distributor ignition system [low resolution pulse]). Sounds like a failed optispark code to me. Hoping not.

I reset the computer again and tried again. The car started and stalled right away.

We seem to be going backwards on this.

Also, as a side note, I went through and re-tightened all of the header bolts. Checked a couple spark plugs (they were clean) and made sure they were all snug and the wires were attached fine. This was done before the coolant stuff.

Thank you.
~Dave

Injuneer

Probably spilled the coolant on the Opti.... often enough to kill the unit.

The LT1 engine has a one-of-a-kind "reverse flow" cooling system. You have to bleed the air out of the system the correct way:

Courtesy of Shoebox

4th Gen LT1 F-body Tech Articles

Generally, not bleeding the air out will cause it to overheat, not run cool.

Clear DTC 16 (pull the "PCM BAT" fuse for 30 seconds), and see if it comes back. If the engine actually starts, the code is not active. You may have gotten the plug wire contacts wet with coolant. Try and dry things out.

Injuneer

With the key on, when you get the engine running, measure the voltage on the O2 sensor (pin "B" in the connector) wires to the PCM. Should be less than 1 volt.

generaldave

I have cleared the code and tried again. The car starts, but stalls out within a second or two. I did not retry to get the codes to see if it's throwing again, but the car still stalls right away.

So next time I am there, I will:
> Bleed the system properly
> Check to o2 sensor voltage (if I can get it running)
> Check the connectors on the optispark for wet/dry

Not necessarily in that order.

Thank you.
~Dave