M50tu sudden Powerloss *SOLVED*

[Tchao]

Hey guys, my M50tu suddenly had a bad power-loss. 2nd Gear pulls like 5th!!!

Problem SOLVED Post #24
updated 8/13/14

Symtopms:
Car has NO power, like extremely retarded timing, and/or extreme Rich/Lean conditions. Engine fires smoothly.

New theory: Very Retarded Ignition ...engine/car smells super hot after just a few test runs, the exhaust is mega hot (than normal)

What can cause the stock 413 DME to retard timing so insanely?


What I have currently done: update 8/6/14

-Fuel flow is verified good = FPR was replaced with a known working one, fuel filter replaced, flow checked at rail was normal, return line flow was dynamic with throttle. Injectors are getting 13.5v power supply.

-MAF was replaced with 4 known working ones. Car idles just fine, car runs smooth, no inherent misfires or bad timing, just seriously down on power.

-Double checked all vacuum connections, everything seemed OK. Even if there was a small leak, that unmetered air should be minuscule at 3K RPM plus....

-Pulled the plugs; PICS to follow

-Car failed Emissions with elevated levels of Hydrocarbon, indicating rich conditions (plugs say otherwise!)

-Crank Position Sensor is tightly mounted

-Vanos stuck at retard? IDK, I took the car in 2nd gear through the revs, and at 5-6.5k RPM the power did not get any better, can I conclude Vanos is OK?

-Cam Sync replaced and still Nada

-Unplugged TPS, MAF, Knock Sensors one at a time, same problem persist


Background:
M50tu stock w/ 413 DME (stock)
Swap has been running strong and fine for 20K miles.
This happened after installed a charcoal canister, but I uninstalled the same night, problem did not go away. (Reason for install was emissions test)


Thanks for your time and help!
-San

- - - Updated - - -

[Tchao]

Updated

[RobertK]

Confused, is the fuel vent valve hooked up and pulling a vacuum on your gas tank?

[Tchao]

updated

[Tchao]

updated

[Tchao]

Ok, finally posted pics, and updated what Ive done.

Any brain storm ideas welcomed!

Thanks,
-San

[DesertBMW]

Car has NO power,
Car idles just fine, car runs smooth,

Engine has no power, engine idles just fine, engine runs smooth. I know you are not a noob.

Bosch +4 are not recommended. You should use original two prong spark plug, prongs protrude more into the combustion chamber. With a good quality scanner you can monitor data in real time, there you can check for timing and how much ECU has to trim for fuel.

[Tchao]

What I meant to convey is the engine is not mis-firing, therefore running smooth, just a total lack of power, like one would say put timing to 5 BTDC.
This hints to me that it maybe a calibration problem, like a bad maf telling the DME 1/2 the amount of air in reality. But Ive replaced the MAF with 4 others! Nada.

I dont think the DME can retard timing that far out of spec, correct me if Im wrong.

[mpowerful]

Any codes?

[Tchao]

Yes, just the same code it always has, 1221 EGO sensor. Its been missing the O2 sensor since day 1. SHe runs a tad bit on the richer side, but with 115F heat here in AZ, its a good thing.
Ive unplugged the ECU for a few hours to reset it, still the same driving behavior with no codes.

[Wanganstyle]

Try unplugging the following one at a time and driving it to see; I had a bad cam position sensor and it drove like craptastic. Car only needs water temp sensor and crank position sensors to fire up and idle

#1 Knock sensor comes to mind
#2 afm or its wiring ( so drive with it unplugged)
#3 perhaps tps?

[Tchao]

Unplugged the MAF and TPS already, no real change.

Knock sensors will be unplugged here shortly, just waiting for it to cool down, its like 106F outside right now.

[Tchao]

Nope, not the knock sensors either.
Errrrrrr

[mpowerful]

Can you change dme or tune. Or even easier just diconnect battery and let any ecu learn go and see how it acts

[Tchao]

Disconnected the DME after every "fix" I did just to make sure it starts from scratch. Nada.

I think I found the problem, my Cam Sync reads 6-million Ohms....Bentley states 540 ohms.
I searched the forums to for bad cam sensor and saw other people's problems were similar to mine. Ill pick up another from the yard tomrw and report back. **Fingers crossed**