One issue after the next with my S. Really haven't driven it since the end of summer. Started with seeing coolant on the trans. Replaced the thermostat housing which led to the water pipe needing replaced. After that I drove it one day and had oil leaking on to the downpipe. Just replaced the seals on the oil filter housing along with the seals for the oil cooler that's attached to it.

Started it to bleed the coolant. Started up perfect, let it warm up but I didn't have enough coolant to fill the system. Shut the car off and ran to get more coolant. Came back about an hour later to finish bleeding it. The car started up, revved and sounded fine but when it idled down as soon as it hit 1k it stumbled and died.

Started it again and gave it a little throttle. It kept idling but sounded terrible! Spitting, popping and shaking.

Went through and checked all the connections and found nothing.

Now it just starts as if everything is normal and as soon as it idles down it sputters and dies.....

It is throwing a CEL (non blinking) but I have no way at home to scan.

Anyone have any advice or theories?

 

high pressure fuel pump. it's under warranty 8yr/120k miles.

 

Fuel pump or clogged gas filter most likely from those symptoms, but given that you have been operating in the engine bay something might have come loose (electrical) or possibly a vacuum line moved/cracked/missing?

 

Fuel pump was replaced around 120k, it has 150k on the clock now.

I'm going to go back through and re check everything. Hoping for something loose.

 

150k? Really check out all those vacuum lines carefully, but that scan tool for the CEL will save you some headaches and at least a 6-pack of beer while looking in all the wrong places,...

 

Went back through the engine bay and didn't find anything loose.

Here's a short vid of what it's doing.
Need to pick up an OBD2 scanner and see what codes are being thrown.

 

Oooo,... don't do that anymore, get the scanner on it.

 

Here's the list of codes I'm reading.

P0100
P0687
P113B
B2AAA

 

I have no clue what the last two are. Can't fine reference to them anywhere.

 

P0100=MAF error
P0687=ECM voltage short error
P113B=Also MAF error
B2AAA=?

Does it smell like it's running rich? It sounds like the leaking coolant may be shorting out a few wires, possibly leading to the MAF sensor and the ECM is detecting this as a short? That sputtering is very typical of a bad MAF sensor. I would try unplugging the sensor and see if that makes your engine run smoother. For some reason, this helps when you have a bad sensor.

But do it on a properly working engine with a good sensor, and for some people (including myself) it makes your engine run terrible...I have no idea why that is.

 

Is it impossible to get the MAF sensor wire plugged in upside down on that model? Does seem to point to a dirty MAF, you said it had been parked a long time, right?