I hate car problems that go away on their own

"Boss2452stolemylunchmoney" (boss2452stolemylunchmoney) 01/26/2015 at 18:48 • Filed to: None

2

10

So my car (300m Special) started this morning and died almost instantly. Then would not restart... But acted like it wanted to. Whatever, drove the wife's car. So when I get home, check the DTC's. Nothing. Then I pull the fuel pump relay and pull a plug to check for spark. Plug reeks of fuel. Ground the plug and have my lovely assistant turn over the engine. Well, not only does it have spark but a ton of fuel mist sprays from the hole... And it fires up! So, put everything back together and try it again. Now it runs fine. How the fuck does a modern-ish car get flooded without tripping a DTC?

Zipppy, Mazdurp builder, Probeski owner and former ricerboy > Boss2452stolemylunchmoney 01/26/2015 at 18:57

1

My father's car has been doing the same over the past few months. It occasionally stalls at random, sometimes with no CEL.

V8Demon - Prefers Autos for drag racing. Fite me! > Boss2452stolemylunchmoney 01/26/2015 at 18:58

7

Relavent:

Boss2452stolemylunchmoney > Zipppy, Mazdurp builder, Probeski owner and former ricerboy 01/26/2015 at 19:34

0

They are the worst. You're father's sounds like failing fuel pump. Should run it low on fuel and pop in a new one.

Zipppy, Mazdurp builder, Probeski owner and former ricerboy > Boss2452stolemylunchmoney 01/26/2015 at 19:49

0

I doubt its a fuel pump, the car works fine without the MAF plugged in.

The car back in October got a CEL with P1415, or when the MAF is disconnected, it got a P0102 (should be expected), but the engine runs better without the MAF, and a new one didn't solve the issue, the engine hesitates for a second when trying to accelerate.

Been getting a P1424 recently (vacuum leak), and the symptoms have been the same as before, the CEL is intermittent this time though.

The car is a 2006 BMW 3 Series btw.

Boss2452stolemylunchmoney > Zipppy, Mazdurp builder, Probeski owner and former ricerboy 01/26/2015 at 20:09

0

You're probably right. When you unplug the MAF, it reverts to open loop mode.

AMGtech - now with more recalls! > Boss2452stolemylunchmoney 01/26/2015 at 21:59

0

Honestly not sure how this happens. I have seen this happen on some LR3's and a Kia Rio. I usually throw in plugs and a fuel pump relay, and reset the adaptations. Always fixed the Rovers, but the Kia came back a couple weeks later. Sent him to the dealer and I never heard anything more about it.

I seem to remember something about cars like yours having an issue with the engine module. I think it was like an intermittent problem with either injector or ignition coil driver circuits. Though I don't recall if that ever caused a flood, I think it was just intermittent misfires on the affected cylinder (usually not more than one cylinder). Actually the more I think about it the less I think that's your problem. So.... I don't know.

Boss2452stolemylunchmoney > AMGtech - now with more recalls! 01/26/2015 at 23:35

0

I've heard a wiring harness that runs near some cooling tubes can get some degradation of the insulation which can cause a short and destroy the PCM. But that usually is pretty noticeable and not intermittent.

AMGtech - now with more recalls! > Boss2452stolemylunchmoney 01/27/2015 at 00:26

0

Hmm, probably wouldn't be such a localized problem either. Usually those sorts of problems have lots of crazy symptoms.

Boss2452stolemylunchmoney > AMGtech - now with more recalls! 01/27/2015 at 06:32

0

Yeah. I would think this would be a sensor issue. But none of them are reporting issues. Would a malfunctioning pressure regulator show up in the codes?

AMGtech - now with more recalls! > Boss2452stolemylunchmoney 01/27/2015 at 09:58

0

No, it wouldn't. But sensors don't always show up either. That's why the ability to read live sensor data is so important. If your pressure regulator has a vacuum hose attached you can test it quite easily. Remove the vacuum hose and inset a toothpick into the regulator, if there is fuel on the toothpick it's bad. If you're not sure, hit the toothpick with a lighter, if it flares quickly there was fuel, if not then there wasn't.