I have a 1999 jimmy with 4.3. It runs great till it warms up. Then when I stop it shakes and wants to die. I have only gotten 1 fault code, for multiple misfires, since I did all the work on it . I started with changing the timing chain. It helped some. I have installed a new distributer, crank sensor, cam sensor, tps, catalytic converter, oxygen sensor #1, fuel injector spider. The compression is good in all cylinders, fuel pressure tests good, fuel injectors test good with noid tester. Spark plugs and wires are only about a year old. Broke the temp sensor, so I had to install a new one also. I have installed a used ignition module and EEC from the junk yard. Nothing seems to help. Any ideas?

 

**Moved to Engine & Transmission**

 

I was getting a similar thing happening, and then finally the Oxygen Sensor behind the Catalytic Converter (Bank1 Sensor 3) died, and it threw the code.

I’d hate to say throw new parts at it though until it goes, and your Computer tells you the Oxygen Sensor is dead, but it sure sounds like this is what’s going on. My thinking on this was that the one upstream was going, and the one downstream usually goes shortly after.

 

That oxygen sensor after the cat is there to monitor the efficiency of the catalytic convertor. It would not be causing a misfire.

Weak coil? Has the cam retard been check after replacing that distributor?
Was a crank relearn also done after the crank sensor replacement?

What is an EEC?

 

It finally gave me a code for left bank oxygen sensor. I then ran the jimmy with the code reader in drive mode and hit record when it started to misfire. It showed the left bank oxygen sensor putting out 0. I replaced the left bank oxygen sensor and it seems to have fixed it.

 

How do you check the cam retard and the crank relearn? I have not done these things. It is running but probably not as good as it should. This is my wife's main car and I want it to be perfect if possible. She loves this car.

 

Unplug the MAP sensor see if it still does it, if so, get a new one. An MAP sensor is to the left of the spider injector plug and has three wires.