Ok, was having a misfire when accelerating for about a couple of miles, the it would start accelerating without missing and run fine. Then, when it would rain hard, the Blazer just would not start. A mechanic changed the dist. cap and rotor about 9 months ago. Did not use AC delco. Well, the service engine soon light never came on while it was misfiring. And it was misfiring, I could feel it. Checked the dist. cap and it just did not fit just right. Put in a new AC Delco cap and rotor and it stopped misfiring and is running better than it has in over a year. Now, however, the service engine soon light is on reading "random misfire pending". I don't get it, the misfire stops and then the light comes on! This time last year I had major problems with it and after 2 mechanics (the first one could not figure out the problem and changed plugs, wires, cam position sensor), the second mechanic found out the new idle air control we put on (we changed it and it ran better but still would stall out) which was not AC Delco was no good. The 2nd mechanic put on AC Delco and it ran good again until the misfire on acceleration started. Now, during all this bad time, the SES light Never came on! Matter of fact it was on before all this happened and when it went out, my problems started. Now that it is finally running good again, the light comes on! What could be going on?

 

Also, this code shows "pending", what does that mean? I haven't had a code show "pending" before.

 

pending codes mean the ECM has detected something is wrong but did not yet set the check engine light. Did you have the codes cleared after the work was done? If not it may be an old code. If you do not have a scan tool you can do this by disconnecting your negative and positive battery cables from the battery posts and touching the cables together. This will eliminate all stored codes. If the pending comes back you may have an issue still but not often enough to illuminate the check engine light.

 

thing is, the service engine soon light was on when I got the pending code, that is why i had it scanned. The light came on yesterday, and I had it scanned and thought it was maybe an old code from the misfire that was happening before we changed the dist. cap (by the way, it did not come on when it was clearly misfiring). So, it came back on we had it scanned again and the was when it was showing pending. However, it is running so much better than and smoother than it has in the past year (and the light did not come on during this past year when it was having various problems) and now the light comes on? Wondering if I am having computer problems.

 

Well, decided to try Marvel Mystery Oil in the gas. I also put in the oil for that lifter problem that lifter problem that I have on start up. Well, the lifter noise quieted and the Service Engine Soon light went out after driving about 1 mile. Go figure!