Loss of power while driving

[smokinm6]

Hey guys,

I've been trying to figure out what's going on with my 91 850i and it's been driving me crazy for the last couple weeks, so I figured I'd see what the community has to say.

Basically while I'm driving (most notable on the highway at steady speed) the power will cut out and to restore power I have to get off the gas and then get back on. Sometimes it feels like the power goes out completely and sometimes it feels like it's on 6 cylinders. When I get off the gas and get back on the power is restored, until it happens again. Sometimes quite frequently.

There are no lights coming on when it happens.

Any ideas?

Items replaced in the last year or so:
Spark plugs
Fuel Filters
Fuel Injectors
O2 Sensors
Intake Gaskets
Ignition Coils & Wires

Thanks,

Ismael M

[8eights]

How bout a pic of the 88 M3 first?)

Could be several things, Sounds like a intemittent short, Are all the plugs nice and snug into place and in good condition? All fuel relays seated properly and good working order? The Maf plugs locks in good shape and not just hanging on to the mafs? DK's move freely? Check the plugs, Caps and Rotors and all important connections, Any Check engine or EML lights?

[wokke]

do a fault read out.
Gets you to a result much quicker than all guessing.

[nacree]

do a fault read out.
Gets you to a result much quicker than all guessing.

Wolf,

How can he do a fault readout if he has no CEL or EML Light? I am interested in this issue as I have been experiencing the same problem for a while.

Thanks,
Nathan

[Fatandre]

What about stomp test?

[nacree]

What about stomp test?

I'm not sure any method will give you a fault list if you have not had a CEL or EML light indicate a specific problem- but couldn't hurt to try.

Thanks,
Nathan

[IJustDrive]

I'm getting the exact same thing. A stomp test gives me 2247 (Ignition Secondary monitor) what the heck does that mean? Bank 2 (7-12) (LH) drivers side. It just started doing this a couple of weeks ago. No other lights or indicators.

[wokke]

Wolf,

How can he do a fault readout if he has no CEL or EML Light? I am interested in this issue as I have been experiencing the same problem for a while.

Thanks,
Nathan

I'm not talking about the Stomp test which requires the CEL. I mean a read out using the BMW software DIS/GT1 what the dealer uses.

Cheers
Wolf

I'm not sure any method will give you a fault list if you have not had a CEL or EML light indicate a specific problem- but couldn't hurt to try.

Thanks,
Nathan

There are plenty of faults which are not indicated by the CEL. O2 sensor out of range for example.

I'm getting the exact same thing. A stomp test gives me 2247 (Ignition Secondary monitor) what the heck does that mean? Bank 2 (7-12) (LH) drivers side. It just started doing this a couple of weeks ago. No other lights or indicators.

where did you get this code translation from? You have DME version M1.X which doesn't provide this code according to my list.
But I've had a code in the past on my car which wasn't listed either so to me the stomp test is just an indicator to take a close look using professional equipment.

[mojocoggo]

I'm getting the exact same thing. A stomp test gives me 2247 (Ignition Secondary monitor) what the heck does that mean? Bank 2 (7-12) (LH) drivers side. It just started doing this a couple of weeks ago. No other lights or indicators.

This sounds like the cylinder ID sensor for the second bank. It's a sensor that is an inductive pickup around spark plug wire #12 that tells the DME when that cylinder (and that the bank as a whole) is getting spark. If it gets no reading it will run in limp mode on 6 cylinders.

[wokke]

This sounds like the cylinder ID sensor for the second bank. It's a sensor that is an inductive pickup around spark plug wire #12 that tells the DME when that cylinder (and that the bank as a whole) is getting spark. If it gets no reading it will run in limp mode on 6 cylinders.

I had a problem once with the doughnut but it didn't trigger the CEL on my car. As stated above by me 2247 is not a valid code for the M1.X Motronic software.

[8Tech]

You should definately plug into the diagnostics to check for fault codes.

That sort of fault would indicate an intermittant misfire causing the engine to go into limp mode to protect the cats.

Did you new leads come with new sensors or did you have to assemble 2 leads with the old sensors?

Also check those caps and rotors.

8Tech.

[IJustDrive]

I had a problem once with the doughnut but it didn't trigger the CEL on my car. As stated above by me 2247 is not a valid code for the M1.X Motronic software.

I didn't find valid lookup for this code, but made an assumption. Probably wrong given my ignorance. Stomp for bank 1 management=5 stomps, bank2=6 stomps. Bank one was fine 1444, bank two was 2247. Most charts only have codes for bank 1 so.... I just lookup up 1247 and ....

[smokinm6]

I had replaced the wires that came with new sensors not too long ago, but being that they weren't original I was starting to think that maybe I got a bad set...

I'm going to try to get it hooked up to a GT1 this week to see what it says...I'll keep ya'll posted.

Thanks,
Ismael M

~~~~~

8eights...here's a pic of the 88 M3...

[didchris]

Are your new wires Magnecor ?
Regulary problems with their sensors that do not work

[pollack137]

Had exactly the same symptoms. After replacing right side wire set, sparkplugs and fixing intake leaks problem was gone. Unfortunately because I did everything at the same time I don't know which repair fixed the problem.

[Kapitan]

A sudden los of power, and coming back to normal afrer releasing the pedal, is probobly the fault of the accelerator pedal potentiometer, had the same problem with my car, and changing that part helped.

[ByMW]

Just to add to the confusion - I had this symptom when one of the MAF sensors failed. Engine would idle fine, and accelerate fine, but would drop into 6-cylinder mode under sustained partial throttlle, such as cruising on the freeway. Fault code was "lambda sensor" on the Peake tool.

Good luck

[ogorek]

Are your new wires Magnecor ?
Regulary problems with their sensors that do not work

I have exactly that problem! Everything begun after changing my wires to red magnacores, irridium spark plugs and msd blaster ss coils. When i drive slow everyhing is ok but when i hit the highway on higer rpm it suddently stalls. I can hit the pedal to the floor it even do a kick down but has not enough power to accelerate. If i loose the pedal and then hit it again everything is fixed. Please tell me more...

[duje]

I have exactly that problem! Everything begun after changing my wires to red magnacores, irridium spark plugs and msd blaster ss coils. When i drive slow everyhing is ok but when i hit the highway on higer rpm it suddently stalls. I can hit the pedal to the floor it even do a kick down but has not enough power to accelerate. If i loose the pedal and then hit it again everything is fixed. Please tell me more...

Same here (new OEM coils, red Magnecores, HI FLOW fuel pumps), intermintent CEL light and instant loss of power, release and hit the pedal to the floor, I hear a thump in the exshaust and power is back, next traffic light CEL back on and engine looses power (in my opinion one bank is flooded with fuel, causing missfire). Original Magnecore sensors were faulty so I replaced them with drilled OEM sensors.

[ogorek]

Did it help? If the sensor is faulty it limits fuel on that side

[duje]

Did it help? If the sensor is faulty it limits fuel on that side

No, with original Magnecore sensors, car wouldn't start, this started happening few months with Magnecores in the car. I don't think it is the wires fault, all sensors show good resistance values, including crank sensors. Stomp test on my car is not working, so I need to find computer to read the fault. I suspect MAF, but without proper diagnostic I will probably take the engine apart and change everything before I found out what is wrong.

[smokinm6]

Well...I went out and bought original wires and replaced the non-oem ones I had purchased and voila! Car is back to normal... Seems like BMW has a stronghold on that reference sensor...

[8eights]

8eights...here's a pic of the 88 M3...

Too cool, Nice to see other that red too, Thanks!

[EEDegreeToDrive]

I'm getting the exact same thing. A stomp test gives me 2247 (Ignition Secondary monitor) what the heck does that mean? Bank 2 (7-12) (LH) drivers side. It just started doing this a couple of weeks ago. No other lights or indicators.

This sounds like the cylinder ID sensor for the second bank. It's a sensor that is an inductive pickup around spark plug wire #12 that tells the DME when that cylinder (and that the bank as a whole) is getting spark. If it gets no reading it will run in limp mode on 6 cylinders.

+1 I had an intermittent CID probe and it would drop down to 6 cylinders sometimes without a CEL.

I had a problem once with the doughnut but it didn't trigger the CEL on my car. As stated above by me 2247 is not a valid code for the M1.X Motronic software.

I've had 2247 on my motronic. EDIT: I also had a mystery code 2235 a few weeks ago that wasn't on the charts..

I had replaced the wires that came with new sensors not too long ago, but being that they weren't original I was starting to think that maybe I got a bad set...

A sudden los of power, and coming back to normal afrer releasing the pedal, is probobly the fault of the accelerator pedal potentiometer, had the same problem with my car, and changing that part helped.

Well...I went out and bought original wires and replaced the non-oem ones I had purchased and voila! Car is back to normal... Seems like BMW has a stronghold on that reference sensor...

I bought a set of Beck/Arnley wires that had bad probes. I suspect there is a proper orientation to installing the probes. Installing them backwards would cause an inverted waveform which might be enough to work properly on some cars/ignition coils, but drive other cars nuts.

On the CID probe, I measured a short between one of the signal wires and the ground pin (3 I believe). My solution, 1000 miles from home, was to float the ground on the cable connector by sticking a piece of plastic in the connector and isolating it from ground.

I returned my Beck/Arnley wireset and bought a CID probe on Ebay, then hacked up my real cable, installed the new probe, and resoldered my plug wire.

Perhaps my 750iL chips from Shogun have additional blink codes?

[IJustDrive]

Well...I went out and bought original wires and replaced the non-oem ones I had purchased and voila! Car is back to normal... Seems like BMW has a stronghold on that reference sensor...

Great news!! I think I'm going to start here as well