fried pcm? or mechanical problem
fried pcm? or mechanical problem I am lost here I have 1998 corvette, automatic and installed a 408 stroker,224/230xe cam, long tube , LS2 intake, LS2 throttle body, 85mm maf. I am using HPtuners and have a mail order tune. The car was running decent with the mail order tune but running extremely rich at wot after installing wide band it showed 10 afr
But besides running rich it pulled through all the gears. I take it in for a dyno tune the first two pulls are clean even though very disappointing #'s
Tuner does some adjustments with his laptop the next dyno pull engine shuts down in the upper rpm's and backfires. Does the same next pull tuner is scratching his head he don't know what happened he thinks the maf is maxed out but I don't think so. The tuner puts the original mail order tune back but it's still doing the shutdown.I take the car test it out on the street as soon as you go wot it shuts down as if you turned off the ignition. Could the pcm be damaged? I disconnected the maf (same results), I disconnected the front o2 sensors (same results) and even though it's running open loop still runs extremely rich no changes in the afr. It idles fine and drives fine just once you go wot it immediately shuts down. Any ideas on this? My next step is to swap out the pcm
But besides running rich it pulled through all the gears. I take it in for a dyno tune the first two pulls are clean even though very disappointing #'s
Tuner does some adjustments with his laptop the next dyno pull engine shuts down in the upper rpm's and backfires. Does the same next pull tuner is scratching his head he don't know what happened he thinks the maf is maxed out but I don't think so. The tuner puts the original mail order tune back but it's still doing the shutdown.I take the car test it out on the street as soon as you go wot it shuts down as if you turned off the ignition. Could the pcm be damaged? I disconnected the maf (same results), I disconnected the front o2 sensors (same results) and even though it's running open loop still runs extremely rich no changes in the afr. It idles fine and drives fine just once you go wot it immediately shuts down. Any ideas on this? My next step is to swap out the pcm
Every hurt pcm I ve seen, they wouldnt run at all. I d suspect the tune, and the question is how or what the tuner did exactly. Other than that, when it shuts down (if you were on a dyno) the easy tests are to check spark, then fuel pressure and electrically at the injector.....Id be worried actually if the dyno operator didnt break out a noid light and a spark light real quick to check...its a 1 minute thing on the dyno and could point in the right direction, ignition or fuel or both.
Thanks for all the advice I am going to do another data log this weekend and hopefully I can post it on here. It's strange on the original tune (mail order tune) it ran fine did not shut down when going wot. I drove the car 2 hours to the dyno facility with no issues. I arrive at the dyno the first two pulls where clean no problems. I was watching him play with his laptop and the next pull once he went wot in 3rd gear it shut off instantly and backfired. Continued to do that and he gave up said the maf was maxed out causing it to shut down. I left the dyno and flashed the original mail order tune but it's still doing the shut down at wot it runs fine normal driving.
Since I put back the original mail order tune why isn't the car running like it was before going to the dyno?
It will do this in any gear 1st, 2nd, 3rd it don't matter what gear or speed once the pedal is completely floored the car cuts off like I turned off the ignition
Since I put back the original mail order tune why isn't the car running like it was before going to the dyno?
It will do this in any gear 1st, 2nd, 3rd it don't matter what gear or speed once the pedal is completely floored the car cuts off like I turned off the ignition 
