That's the one. Report cam sensor retard value (use single * cam sensor retard PID in Car Gauge Pro).

Don't forget to do the test I asked for to ensure the misfire detection is working properly.

Know that for Blazers - in Car Gauge Pro, Misfire Counter #1 reads misfires for cylinder #2, andMisfire counter #2 reads misfires for cylinder #1. The other cylinders 3-6 are correct.

 

Sounds very familiar to me. Is it a single jerk at a time, noticed on the tach - or is a repeating miss for some time? How long does it miss? Is it at 40mph 45mph 50mph, etc. Never below what speed and never above what speed? Only in overdrive, or also in 3rd gear? What is the tach speed, mph, and gear when it misses? After driving for how long? Seriously.... I need better info because I'm not there to observe, myself.

 

i only sense the miss in 4th gear 2100ish rpm after driving less than 5 mins. some times it is a subtle miss sometimes it is a dead hard miss. it does NOT do this every trip i make 1 out of 4 i presume. i did the gauge set up just like you suggested in another post about car gauge pro. the misfires per cylinder were higher on cyls 2,3,4. i did reset them. then pulled a plug wire #5 it registered around 580 before it triggered a cel.
the value for csr is -4.8. it was not missing at this time.
what size socket fits the distributor hold down? i could not get 10mm with swivel socket on it.
if the distributor gear is worn would it giv a different value? sometimes? due to slop?
seems i set up gauge set and did not save profile.

 

i only sense the miss in 4th gear 2100ish rpm after driving less than 5 mins. some times it is a subtle miss sometimes it is a dead hard miss. it does NOT do this every trip i make 1 out of 4 i presume. i did the gauge set up just like you suggested in another post about car gauge pro. the misfires per cylinder were higher on cyls 2,3,4. i did reset them. then pulled a plug wire #5 it registered around 580 before it triggered a cel.
the value for csr is -4.8. it was not missing at this time.
what size socket fits the distributor hold down? i could not get 10mm with swivel socket on it.
if the distributor gear is worn would it giv a different value? sometimes? due to slop?
seems i set up gauge set and did not save profile.

 

Misfire detection seems to be working. Should be a 10mm head on that hold down bolt. Try 1/4 inch drive. -4.8 is not very far off - if distributor gear was worn it would be a lot further off (unless someone has already adjusted it back towards zero). 4th gear at 2100 rpm should be about 65-70mph with the TCC engaged. Less speed if TCC is not engaged. Based on this, is TCC engaged when misfire occurs? Is misfire sometimes a dead miss (you can feel regularly spaced multiple misfires for some period of time), or is it just a severe 1-time occasional miss? I'm going to be traveling this weekend starting tomorrow morning and ending Monday - so please be patient.

Couple of things to do in the meantime that won't cost you anything. Test resistance of all 6 injectors at the connector on top of the intake and look for connector pins pushed out of place in the connector. Take that distributor out, take the clamp off and elongate the bolt hole with a dremel so you can turn distributor a little bit both ways. Inspect the distributor gear for wear and if OK reinstall and set the CMP retard to zero. If gear is worn or if you have excessive end-play, just plan on installing the Skip White distributor. Also you can plot (not display - cycling of STFT is too fast) the STFT and notice if you see a difference in the cycling when the misfire occurs.

The last thing I want to place in the back of your mind is what happened to my Blazer. 1.5 years ago. I was getting what felt like an occasional sharp single random misfire at 50-55mph steady speed (no higher, no lower) with the TCC engaged - not all the time - could see it on the tach. Set a P0300 a couple of times. Finally I took it on a 250 mile RT and the 3-4 clutches went out of the trans - left me sitting on the side of the road after picking up my inlaws from the airport in Chicago. Got the trans fixed - no more "misfire" or P0300. Not saying that this is what yours is experiencing - just pointing out that other things can feel like misfires and set misfire codes (even when misfire detection is working correctly). This is why I'm asking so many question about your misfire.

Good luck and best wishes for a successful repair.

 

is TCC engaged when misfire occurs?""
not sure i can add that "guage" and watch
"Is misfire sometimes a dead miss (you can feel regularly spaced multiple misfires for some period of time), or is it just a severe 1-time occasional miss?"
it has done both
" If gear is worn or if you have excessive end-play,"
how much is too much?
Also you can plot (not display - cycling of STFT is too fast) the STFT and notice if you see a difference in the cycling when the misfire occurs.
i know not what STFT is. i will have to research this

there WERE significant misfire counts on all cylinders. more on some. i had not reset the mil. for a couple weeks.
Thank you for your time. maybe i and others will learn something. i do like this App i will learn things from it

 

short term fuel trim.... DUH

 

[QUOTE=Lesmyer;683170] I was getting what felt like an occasional sharp single random misfire at 50-55mph steady speed (no higher, no lower) with the TCC engaged - not all the time - and the 3-4 clutches went out of the trans - just pointing out that other things can feel like misfires and set misfire codes (even when misfire detection is working correctly). This is why I'm asking so many question about your misfire.

Good luck and best wishes for a successful repair.
That describes my conditions and occasionally I would feel a surge like more power,the opposite at the same speed. I can see with 20/20 hindsight that the transmission was telling me something ! I learned something new, Thank you, Lesmyer P.S. I hate doing exhaust work ! No broken bolts, thank heavens.

 

several trips were taken with no misfires. this morning however I felt a slight miss fire then took these screen shots the misfire numbers did not change for 35 miles

 

I would monitor "misfires" instead of "history misfires". That way they reset to zero every few seconds. Something seems to be going on with #4 and #5.