MAF help needed.....




Issue I'm having is once im in closed loop my car will stall EVERY time I come to a stop in gear(as long as I'm open loop it runs like a swiss watch)....I have to bump up to neutral and then shift to D and feather to leave a light to keep from stalling. Have had several shops look at it and the issue doesn't even set a code of ANY KIND, even when It stalls. The only thing it has ever shown was on one(and only one) occasion the log looked like one of the MAFs signal cut out for a split second but was then back like nothing ever happened. Since this is the only indicator that has popped up I'd like to throw a different pair of MAFs in there and see if it's the fix or if I need to keep digging.....thanks Guys
Last edited by skratch77; Jul 28, 2020 at 08:37 AM.
Issue I'm having is once im in closed loop my car will stall EVERY time I come to a stop in gear(as long as I'm open loop it runs like a swiss watch)....I have to bump up to neutral and then shift to D and feather to leave a light to keep from stalling. Have had several shops look at it and the issue doesn't even set a code of ANY KIND, even when It stalls. The only thing it has ever shown was on one(and only one) occasion the log looked like one of the MAFs signal cut out for a split second but was then back like nothing ever happened. Since this is the only indicator that has popped up I'd like to throw a different pair of MAFs in there and see if it's the fix or if I need to keep digging.....thanks Guys
If it is maf related you can unplug them to troubleshoot, if the car still stalls in the same low speed/stopped/light accel condition. If the mafs are fine and the transmission isnt causing it you should also look for a vacuum leak, but it sounds like you were already logging fuel trims to make sure they were low?
Last edited by blurred; Jul 28, 2020 at 11:37 AM.




I'm curious though, does the TCM operate under loop parameters as well???
Last edited by hachiroku; Jul 28, 2020 at 01:27 PM.




And the computer is not seeing ANYTHING out of order whatsoever, NOTHING!!!!
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Was at one of the best indy guys shops on the east side of the country for over a month and they could get it to do exactly what I described but NEVER would anything actually flag....and they were using oscilloscopes, STAR and even flux-capacitor smoothing devices and STILL FREAKING NADA ON THE CAUSE!!!!
When Tasos and I talked about it about 2months ago he said that it wouldn't be like I was looking for a needle in a haystack but like looking for A needle in a stack of needles, he's been right thus far
as far as the MAF's and signal cut...if your engine stumbles, your MAF values will drop...more than likely its occurring because of another issue and is simply displaying the drop in airflow across the sensor. MAF's shouldn't have dead spots...they'll either be off entirely or not work as expected.




However, that does throw a code every now and then but its a moody one. I had a crack, the car would bog and loose power, but
after shifting from D to N to D the car would be alright. Had a torment of finding the issue and after getting fed up
Pulled off the manifold and hiding in the corner was a crack about 1cm wide. Once that was fixed, the power was mad!







