broda805

iTrader: (6)

my car intermittently dies on me when i make a stop and let it idle I.e stop light , stop sign. it would go rich around 10.1 afr bog and cut out. will not start back up. i found that if i just take out the key and wait till everything is off (around 30 seconds) and try to start it again it fires right up and runs like nothing is wrong but if i dont let everything power off it will not start back up.

could it be that my aem ems is locking up or something? it seems kinda fishy that if i take out the key and let the ecu power off and back on it works fine again. it only happens maybe 1 of every 4-5 times i take it out and only recently


not sure what it could be that would make it happen so intermittently runs fine otherwise

any suggestions on what i should check?

g4ebguy90

When it does this, does your intake get gradually louder till it dies?

broda805

iTrader: (6)

hmm not really, just bogs cuz its so rich then dies

lexforlife

iTrader: (7)

who tuned the aem... can you connect to aempro and look at your map sensor parameter.. key on engine not running see what reading your map sensor is giving you.. should be between 95kpa and 100kpa ... ive seen your symtoms before with a bad map sensor

HiPSI

iTrader: (2)

Mine will do this occassionally if I load it up and then rev drop to a stop. I blame it on a poor unproperly setup tune. I basically have the car running decent, but not fine tuned at all. The only reason I can think that it isn't starting right back up is it might be flooded? 30 seconds would allow it to air out a bit.

broda805

iTrader: (6)

church automotive did the tune, i replaced the map sensor about 3 months ago right before a tune with a new aem sensor, i didnt touch the tune for quite some time then it just started about 2 weeks ago never happened before that.

cant tell when its going to happen so i usually dont have my laptop with me and im trying to hurry and get out the way for them honking cars behind me even though my hazards are on : / lol

what should i be looking for in the tune if anyone knows? usually when i rev it up high and drop it its normal its just those few random times when it suddenly spikes to max rich stays rich bogs and dies, giving it gas doesn't really do anything

Biggu

iTrader: (12)

Sounds to me like the IAC is having issues. take it back to your tuner and tell them your issues.

broda805

iTrader: (6)

Iac wouldn't cause it to peg rich I wouldnt think? I can't make it happen when I want so I don't think the tuner can help if I take it there and it decides to run fine that day

Biggu

iTrader: (12)

no but your tuner can turn on logging in the ECU so you he can then later pull the logs. The IAC dumps air from the intake so if its dumping to much air out then you will have an issue with to much fuel.

Just take it back to your tuner inform him of the problem and they will work with you to get it right. something in the tune is not correct.

broda805

iTrader: (6)

no offense at your knowledge or speculation but i dont understand how would the iac would dump air? i assume you are talking about the idle air control valve? does it not just let air in to allow the motor to idle? and if it is closed with the throttle plate closed the engine would just shut off pretty fast and wouldn't allow it to bog super rich for 5-10 seconds then die, i tried pressing the gas pedal during this to allow more air in but it doesn't do anything just blips the rpm just slightly but still super rich and dies out. ive had the idle air valve stuck open once when i didnt plug it in and it idled fine just super high rpm but afr was in check and i have had it blocked off once as well it just wouldn't start so ive experienced both open and closed and i dont think this is it.

my tuner is 2 hours away i dont want to take it to him if theres a chance where he is just gonna say "i dont know"

like i mentioned before it ran for about 6 months after he tuned it without this happening, then it happened once about 3 weeks ago before i took it back for a retune but i thought it was just a freak thing ran fine for a week then got it retuned i mentioned it to him and he said he'd look it over and said it seemed fine and nothing was amiss during the 2 hour re tune session, he also didnt touch the idle or much of the low end stuff this retune since it was for upping the boost. i was saying hm o well must of been a 1 time thing.

it is very intermittent i cant make it do it. its happened once while just cruising the highway at 65 then i took an offramp let the rpms drop and it started to peg rich i had time to pull aside before it would die and get it started back up again.

once it happened when i was on it, built maybe 6psi of boost then let off and slowed down for a red light

once when i was driving around the neighborhood then it did it at a stop sign

some days i can do all that and hit full boost all day and nothing happens

Biggu

iTrader: (12)

what do I know just trying to help.

its a tune issue. if you cant bring it to the tuner call him that's why phones were invented. The AEM controls how the car is made to idle if its causing an issue its because there is a scaling issue within the tune.

stockhatch

iTrader: (12)

I agree with the suggestion to datalog. Just collect logs until it happens again and you will see exactly what is happening when it dies.