Engine Dies On Next Start Up After Using A/C
 

Hey guys, wondering if anyone has had this problem, did a search but found nothing. This only happens after using the A/C, so here is a description of my problem. After using the the A/C, if I park the car and shut it off immediately, on the next start it will rev up like it's supposed to, the revs will drop to the idle range, but then the engine will die. Sometimes it will take 3-5 start attempts for me to get it running, again this only happens after using the A/C. Now if I turn off the A/C about 1-3 minutes before I reach my destination or let the car idle for about a minute or more before shutdown it will usually (not always) start up on the next start. Again this only happens after using the A/C, if I never use the A/C the problem isn't there. :dunno:

My Car: 2002 X5 4.6is 190,000 miles

does the engine stutter? what if you hit the gas, will it go up and then still die? on my old E39 528 i had this issue - it was the Idle control valve.. not so sure about the M62 engines... do you get any codes? how about the spark plugs? coils? any noises? like from the AC compressor?

just trying to brainstorm this issue here..

It stutters then dies while it's trying to settle into an idle, if I keep my foot lightly on the gas pedal and slowly let it rev down it will usually catch the idle, but if I let off too fast it will die. Installed new Bosch Platinum 4 plugs last year, no codes, coils have never been replaced, but if one or more are bad it should do it all the time, no strange noises, I don't think there's an IAC, that was my first thought.

fuel pump? fuel filter? could the fuel pressure be low? i would not rule out the coil packs... the coil packs could be shorting out to ground intermittently...
do you have INPA? you could hook it up and look at engine roughness - that test could point to some issues with the cylinders...

are you able to hit the gas and take off, like the 4.6iS is supposed to? do you have any loss of power? with or without the AC?

I don't think it's a fuel related issue, I have no power issues at all, 15 minutes before typing this I just spanked a roughly 2008-2010 V8 Mustang, guy pulls up next to me at a light knowing his lane ends in about 1500 feet, needless to say he didn't make it...lol! I don't have INPA, those are all valid reasons, but again it only happens after running the A/C, and that's every time.

it is nice to know that the we still can take on those "muscle" cars... lol...

how about a vacuum leak? MAF? the throttle body might need cleaning? air filter clogged?

when i had my coil issue, i cleaned the MAF (was not a culprit) and cleaned the throttle body.. while the TB was not the issue, there was some crud that needed to be cleaned up, as the butterfly could have been hampered in its movement byt he deposits... Throttle body cleaner is about $5 from a local auto store...

Yeah I'm gonna do the TB and MAF cleaning, I'm a hands on guy so I have plenty of chemicals on hand..lol! But it's so strange that it only happens after using the A/C, it's like the car forgets that I'm not using the A/C any more, like a reset failure almost.

Does it stall whether the air is on or off the next start after using the air?

Could be an injector that starts to leak. This will happen only when the engine reaches a certain temperature. It probably relates to the A/C only because when the A/C is on, the engine is a tad hotter, but the dual temp sensor does not read the temp at the heads.
try to PM Fmugur. he had a similar issue, and it could not be solved by reading GT1 or INPA. He had his car tested at some very specialized shops, and they couldn't figure it out. He somehow caught it though, and it was 1 or 2 leaking injectors (as I said - they will leak, once the temp reaches a certain value - not sure what this value is). He also had no stutter, etc. He also had to let the car cool down, then it would start OK.

Yes, makes no difference.