The Struggle Continues

[ezlnh8u]

I have been having this running rough and extremely rich issue with my vehicle. I will try to be as detailed as possible with what we have replaced and troubleshooted.

The car turns on but runs with a surging idle and rich. upon disconnecting the fuel rail where the injectors are and re plugging it back while the car is running, it makes the car run normal. perfect idle and no black smoke.

List of things we have replaced.

1:Plugs/Wires/ Cap & Rotor/Distro
2:ICP/TPS
3:Injectors
4:Swapped 3 different ECU's (Same Number)
5:Replaced TB
6:Coolant Temp Sensor
7:02 Sensor
8:Checked the timing
9:Fuel Pump Checked
10:Smoke test done
11:FPR Replaced

I cant do a stomp test as this is a swap on a e10, the car has been running great for the past 4 years, and from one day to another it developed this issue. (Maybe electrical)? Many thanks for the input.

[roguetoaster]

What on the fuel rail did you disconnect when the car was running? Just the injector electrical connectors, one by one? If so, when did the poor running condition stop, after doing all in sequence or just the last one?

How about the AFM, have you checked it out?

[ezlnh8u]

What on the fuel rail did you disconnect when the car was running? Just the injector electrical connectors, one by one? If so, when did the poor running condition stop, after doing all in sequence or just the last one?

How about the AFM, have you checked it out?

Apologies, yes that was checked as well. tried 3 different working ones.

[ezlnh8u]

What makes this issue so strange, is that how is it that unplugging and re plugging that fuel rail from the injectors makes it run perfect, Possible ground or positive issue?

[ezlnh8u]

What on the fuel rail did you disconnect when the car was running? Just the injector electrical connectors, one by one? If so, when did the poor running condition stop, after doing all in sequence or just the last one?

How about the AFM, have you checked it out?

Only one side of the rail, either back or front. I have attached a pic of what I'm talking about.

[roguetoaster]

Well, to point out the obvious there's a disconnected wire or two in pic #1, which is strange.

[ezlnh8u]

Well, to point out the obvious there's a disconnected wire or two in pic #1, which is strange.

Yes, that has been like that for...15+ years since the swap, not needed for the e10. and has never caused me any issues. It is completely wrapped and protected. in the pic its open as we were checking OHM's etc.

[TobyB]

What's an e10?

he pokes, because the 2002 was never called an e10 by BMW.

Have you put a fuel pressure gauge on it?

Unhooking the injectors under power makes me suspect either connections
or the ECU itself. If you've been through 3 ecus, that makes the ecu a pretty
unlikely suspect.
Unless some odd input is sending it into tachycardia, and pulling the rail is the
ecu equivalent of a defibrillator...

hmm.

t

[ezlnh8u]

What's an e10?

he pokes, because the 2002 was never called an e10 by BMW.

Have you put a fuel pressure gauge on it?

Unhooking the injectors under power makes me suspect either connections
or the ECU itself. If you've been through 3 ecus, that makes the ecu a pretty
unlikely suspect.
Unless some odd input is sending it into tachycardia, and pulling the rail is the
ecu equivalent of a defibrillator...

hmm.

I have not tried a FPG, I am considering letting some experts at Bimmerheads taking a look. I am almost at a point of giving up...

t

[dnguyen1963]

What is that huge crack in your picture? Vacuum leak?

[roguetoaster]

Looks like a casting flaw on the VC.

[e30sh]

Have you checked the TPS? Should have continuity (front pins) at idle, near full throttle (rear pins) and open in the middle.

[Jaxx_]

Those looking to help, please read through the other threads OP started before offering troubleshooting:

https://www.r3vlimited.com/board/showthread.php?t=426663

https://www.r3vlimited.com/board/showthread.php?t=426644

[Nader393]

I recently had loss of combustion in multiple cylinders.

Get an IR temperature gun, and check the exhaust header temperatures to see which ones aren't firing. To check spark, get an extra plug, then pull each affected cylinder's lead and attach it to the extra plug, with the electrode grounded. Crank the engine looking for spark.

If temperature gun says it's 1,3,5 or 2,4,6, that aren't firing, then you have an injector bank problem, probably from a bad wire harness. This just happened to me. Injectors are fed electricity from a single red/white wire, and are activated by grounding via brown striped wires controlled by the ECU. Check the injector wire harness for voltage presence. Then check their function by grounding the ECU harness pins. Do this by first grounding pin 36 on the ECU harness to activate the main relay (you should hear it click in the engine bay), then ground pin 17, then 16. Listen for the injectors to click when activated. If there's no click, then there's a break or a short in the grounding wires to the injectors. Or get a noid light and test the injectors individually.

[ezlnh8u]

Small update, I took the car into a known shop that works on E10's and E30's, The mechanic was able to get the car not to run rich anymore, so no black smoke anymore, and no more unplugging the injector harness to make idle normal. But the car on cold starts will idle rough up and down until it gets warmed up. the mechanic did not want to tell me what he did (I dont know why), and just said,

I need to replace the complete wiring harness. It will cost me $2,000 for his shop to do it. Besides that the car runs ok, except for cold starts, It has mustang 5.0 injectors, he also suggested to get an m3 Maff to have the injectors run better with them.