'03 M62 4.4 Dies a Minute Or So After Cold Start...

[tempest411]

The engine will start and run perfect for perhaps 30 seconds, at which time the rpms begin to slowly fall, eventually cutting off. The engine will restart immediately and repeat the same cycle in a shorter period of time. The throttle can be teased to keep it going, and after it warms up a bit, the problem goes away. A full scan with a Foxwell 510 didn't show any relevant codes-just two that have been there forever. One is something about 'Breaking Force Distribution' in the IKE module, and the other is a mysterious DTC in the LCM about a faulty light that works fine. I checked fuel pressure from cold and it was fine at 48 psi. I looked at the coolant and intake air temps and they made sense, though by that time the engine was fairly well warmed up. I checked the MAF by unplugging it while the engine was running and it stalled immediately. I kinda thought perhaps the CCV (vacuum leak), but stalling doesn't seems to be an issue with that, and I don't have any unusual smoke coming from the exhaust either. Although it hasn't generated a code, I DO have an increased idle due to low battery + voltage condition. The voltage as tested is 14.2 while running, which should be good...for any normal car. This has been that way for a long time, but no idea what I can do if the charging system is working normally(?). Any thoughts?

[Magister88]

Hi,

not sure about the 4.4 engine but on mine 3.0i I had similar issue (would start fine and die once rpm started to go down, pressing on gas pedal would keep it alive until it warmed up). I narrowed it down to ICV not working as expected. I took it out cleaned it made sure it flaps when shaken and it fixed the problem.

[tempest411]

That's a good bet, though the 4.4 doesn't have an ICV

[tempest411]

Just an update. I looked at all the sensor inputs from stone-cold this morning and found that the air inlet temp sensor is off by just over ten degrees. The ambient temp was 43-44F. The coolant sensors read within a degree or so of that, but the air inlet temp read 55F. The car was in the shade, so I don't think it was picking up any solar heating. Could this variation cause this symptom...Which was not as pronounced today as yesterday. The engine didn't die, but did it's usual 'stumbling' a bit as it crosses over from open to closed loop operation.

[tempest411]

Just to post the solution to my problem, the issue turned out to be a throttle body spacer to intake seal that had become old and split. When the vehicle was warmed up the closed-loop fuel injection system was able to mask the problem fairly well, but the colder it was at start up, the worse the problem was. If they'd only used a conventional gasket there this never would've happened...

[Homerlovesbeer]

Thanks for the info... Glad you fixed it