Explain this...
Thread Starter
TECH Enthusiast
Joined: Sep 2004
Posts: 595
Likes: 0
From: Clarksville,Tn
Explain this... I was headed down the interstate today running about 85 and the car all the sudden starts cutting out like crazy. Sounds like 2 or 3 cylinders are just dead. I step on the gas to about half throttle and it clears up. Actually it took off like a rocket when all the cylinders started firing again. Let off the gas to a cruise speed and starts cutting out again, step on the gas and it clears up. This went on for about 5 minutes then my SES light came on and the instant it came ON the car cleared up and ran like a champ. That's some crazy ****. Got back in the car after about 5 hours and the SES light was gone and it continued to run like a champ. It was raining and I just put plug wires on it about a month ago so I though maybe I didn't get the boots sealed up good enough. Then I thought the opti might be going out, until the SES light came on and it cleared up. Anybody had this happen to them? I just put the OBD1 pcm back in last weekend so it could be something with that but it did this same thing about 2 weeks ago without the OBD1 pcm. I'm stumped. The only other thing I could think of is when I put the headers on I didn't buy any O2 sensor extensions, I just cut the wires and spliced more wire in with connectors so I'm thinking maybe the connectors were getting wet and shorting out or something. But why did it clear up when the SES light came on???? 
Joined: May 2004
Posts: 1,593
Likes: 267
From: Halfway back on the Highway to Hell...again!
First, you gotta get it scanned to pull up what codes were thrown. Any codes that were thrown will be in its history, so as long as you didn't reset the pcm by disconnecting the battery. without codes, we are just guessing at a number of prob;ems we have experienced with a typical LT1 that has about 27 sensors, over 200 possible codes, and 4 miles of wiring. The advantage of computerization is to pinpoint the problem.
Thread Starter
TECH Enthusiast
Joined: Sep 2004
Posts: 595
Likes: 0
From: Clarksville,Tn
I have no way of scanning right now, my laptop is being an ***. I think I'll put some shrink tube around those connectors and seal them up real good and wait til it rains again and see what happens. This is what I think is happening though, the wires are shorting out when they get wet and that makes the pcm think the O2 sensors are bad so maybe it switches to speed density or some other hard set calibration. That would explain why it cleared up when the SES light came on. I'll try to get my laptop going though and pull the codes out of it.
