Is my crank sensor bad? Will start but pops, backfires, quits until I clear the code
07-01-2005, 12:44 AM
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Is my crank sensor bad? Will start but pops, backfires, quits until I clear the code Took my car to the dyno today and made a base run and on my second run the car just quit twards the end of the run. I thought the dyno guysomehow shut it off. Well then the car wouldn't start let it sit for awhile it started back up but ran like $%it!!!!! got into the upper rpms once we got it started again and BANG!!!!!!!!!!! backfired and sound like a cannon went off. Then it wouldn't start again. Had fuel pressure, spark and all the fuses where good.
Got it going and off the dyno and let it sit for about half an hour got in it fired up and it ran perfect we drove about 20 miles and then the same thing started in, wouldn't run, Cranksensor code SES light came up then it wouldn't start and was poping like it did on the dyno and then it shut down. Cleared the code and it would run. Once the SES light came back on it would kick and sputter and quit running once again until we cleared it. This happened many times on the way home Until my friend who was along and is a good mechanic pulled the TPS sensor plug so it would run in open loop so we could get it home with out a tow bill. Made it half way home and then it quit again. Plugged the TPS sensor back in and it fired right up and we made it home.
So is it crank sensor or what? What would cause this to go out....Heat? Everything ran great before we had it on the dyno. I had one concern when I was on the dyno, I pulled one of my 02 sensors out so we could screw in one of his off the computer so we could get the A/F ratio. So one of my 02 sensors was unpluged durning the runs. Think this had an effect on my dyno # or something to do with that sensor going out?
Thanks for your time...
Got it going and off the dyno and let it sit for about half an hour got in it fired up and it ran perfect we drove about 20 miles and then the same thing started in, wouldn't run, Cranksensor code SES light came up then it wouldn't start and was poping like it did on the dyno and then it shut down. Cleared the code and it would run. Once the SES light came back on it would kick and sputter and quit running once again until we cleared it. This happened many times on the way home Until my friend who was along and is a good mechanic pulled the TPS sensor plug so it would run in open loop so we could get it home with out a tow bill. Made it half way home and then it quit again. Plugged the TPS sensor back in and it fired right up and we made it home.
So is it crank sensor or what? What would cause this to go out....Heat? Everything ran great before we had it on the dyno. I had one concern when I was on the dyno, I pulled one of my 02 sensors out so we could screw in one of his off the computer so we could get the A/F ratio. So one of my 02 sensors was unpluged durning the runs. Think this had an effect on my dyno # or something to do with that sensor going out?
Thanks for your time...
07-01-2005, 08:15 PM
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Just for reference if anyone else searchs and comes across this problem my timing tuner wires that ran the crank sensor burnt against the block and was grounding out that what was causing the missing and backfires. Plugged the stock sensor back in and whamo runs better than before.
Good thing I have a good LS1 mechanic and he got to it before he left for vacation and didn't charge me a dime.
Thanks to Traver Speed.
Good thing I have a good LS1 mechanic and he got to it before he left for vacation and didn't charge me a dime.
Thanks to Traver Speed.
