pcolt94

Wo - nice call. No O2 sensors in closed loop, I think it should go rich - could it lope? I would think it should throw a code.

pipe

Yep Bogus there is only one O2 sensor on the drivers side Y Pipe right directly after the Header collector and it is threaded into the bung and connected. Why you ask? Pipe

bogus

hm... did you check the wiring to be sure none of it was damaged?

Photomania

Hi Pipe,

Your car's problem could easily be something other than the ECM, but I want to tell you that I put another ECM in my 1990 six-speed Corvette and that solved the problem. It all started with "Sys 69" flashing in the dash where the gas mileage registers. This was flashing even as I drove the car out of the individual seller's driveway. He told me to ignore that. I wish I hadn't. Eventually, the car would try to stall out on me while driving down Interstate 95.

Later, the car would get worse and worse, even though I was replacing one by one: the fuel pump, fuel filter, ignition module, ignition coil, rotor, distributor cap and spark plugs. I began to learn that when the SES light came on, I had 20 seconds to find a place to park because once the engine died, it would be 20 to 30 minutes before it would re-start. Thank God for a light weight car because I had to push it across intersections to get it out of the way of angry drivers. It also helps to be 6-foot-3 and lift weights.

Over the months, the situation got worse and I couldn't go more than a mile without the engine dying. Finally, when it wouldn't run more than 10 minutes in my driveway without dying, I called for a rollback wrecker who charged $133 to transport it to an auto repair shop. The guy there hooked up his $4,000 diagnostic machine and said he was pretty sure the ECM had gone bad. As a test, he put the ECM in a freezer for a couple of hours and re-installed the ECM and the engine ran perfectly for 45 minutes. When the ECM got warmed up from the heat of the engine, the ECM malfunctioned. He said the ECM was also turning on the air conditioner and his was causing the battery to go dead within 48 to 72 hours while the car sat in the driveway.
I'm not saying you need a new ECM, but you originally asked for symptoms of a bad ECM, and this is the way mine behaved. -- Eric

pipe

pcolt94 The wire going to the 02 sensor is fine I made sure that when I put the headers on and the Y Pipe that I put a small wire tie on it to keep it from laying on any hot pipes. Now that you mention it my exhaust pipes on the flowmasters look kinda black like it's running rich or something Pipe

Titto Caasttillo

we still want to know if you solved your problem

aklim

13 years later......

Wilson79.vette

ECM is giving extremely hot anybody got any ideas on which wire's I should be checking to see why it's getting so hot =bogus;1555030219]silly question... do you have O2 sensors mounted?[/QUOTE]

Wilson53.vette

[/QUOTE]
no o2 sensors all been welded over in headers. But ecm burns your hand if you touch it agter running 20 minutes no pollution stiff ethier been taking off