8.1 cylinder missing obd recorder

[ctpres]

Just had engine missing and no power problem. Very expensive and "No Problem Found" so far. Looking for low cost way to record "cylinder missing" history. Found Elm 327 usb with gm software for under $20 but not enough info. Retirement $ in short supply so looking for cheap answer.

[Full-Timers]

Cylinder miss is recorded in your PCM and should be readable with an OBDII reader.

[JonBrazel]

Can you elaborate more on the issue? Is it missing under load and has low power or does it run extremely rough at idle and display reduced engine power on your cluster? With some more details we may be able to help you!

[ctpres]

OP here. Background: Saturday - had been driving 3 to 4 hours on interstate type highway, speed around 60/65, outside temp near 105, towing 90 Jeep, DW driving with cruise control on, I was napping, 100 miles from home after 7,000 mile four month trip. I woke to sound of engine reving as if trying to maintain speed on steep grade, but only small overpass, then started missing but seemed to me like more like multiple cylinders in firing order. Pulled off at exit on down side of overpass and parked on side to think. No idle problem, no engine lights, temp guage in normal position - just left of center. Had just passed Cleveland TX. so decided to at least try to get into town. Power was ok up to about 25/30 but no faster. The missing problem was not evident - just struggeling and no faster. Found closed business to park. Did remove doghouse cover to look and the only thing I saw was foil like insulation coming off and laying on top of engine. Glue still sticky so I just pushed it back in place. Workhorse tow to Houston RV park. Monday drove on side streets to RV Masters and only problem noted was first shift or two seemed rough. Did go over 45 at one point and no problem. In shop no error codes, RV Masters drove on freeway for over one hour and could not recreate the problem. Don't have details on everything RV Masters checked but this is the highest rated shop in texas ( rvservicereviews.com) so I expect they did everything. Should get her back in the next few days.

[oemtech]

The new version of the SG has some memory functions... IE - data logging. I also have some test pids for cyl miss and cly miss history. Although I have not tested it this might be of help.

The only other option is a PC based data logger that has the ability to track all cyl miss fires.

[Full-Timers]

As I said the OBDII should detect a missfire.

P0300 Diagnostic Code - Random Misfire

[mfire1339]

Three years ago Mine read #5 cyl miss fire last 4 cycles or something to that effect. It was very accurate. The spark was jumping a 1 inch gap to fire plug.

Mike

[MegaRoadie]

Dealers must have some extensive history recording capabilities through the OBDII Ports since my last road troubles with the Mass Air Flow Sensor had logged 8 failures out of last 56 startups and there was a record that stretched back over 2000 miles since the engine replacement !

Getting ready to make 700 plus mile trip this coming weekend so I will see how the Itasca is doing. Granddaughter's 9 th birthday !

Be safe, enjoy the open roads, and thank a Veteran for our freedoms !

[ctpres]

OP here: OK so OBD should have recorded something but didn't. Any chance this actually could have been a transmission problem?

[DriVer]

Quote:

Originally Posted by ctpres OP here: OK so OBD should have recorded something but didn't. Any chance this actually could have been a transmission problem?

A transmission problem would have shown a gear icon with an exclamation point. Only a Scan Gauge II will show you all the codes that may have occurred or that are stored in the ECM's memory.

In time the codes clear themselves after repetitive start cycles.

If the machine keeps exhibiting a problem, a stop at a service center may be your best option to get a good diagnostic readout. If you need help finding a service center, we can help you with that.

[speed racer]

Have you considered an exhaust restriction. How old is your unit and how many miles on it. A cloged cat. converter will cause a speed resriction and low power.