Searched. Have Clues. No Luck Yet.

[ericbendler]

Ok. My e34 has been off the road for 2 months. Now. Instead of turning it into my local shop I have been searching for the answer.

I now have the Peake Code Reader and got Code 1A meaning


"Control Unit Supply"


My EPROM? My DME? I have looked on this forum and found only one other person who was confused like me. I am checking the Conforti chip in my DME.

But I don't know what else to check.

Cylinder #1 does not fire. I think it has something to do with rain water, as I have had the problem in the past. This time, however, when I replaced the spark plug and boot (which cured previous ailments), I get the same slugging sputter with no power.

Squirted some water on 5 of 6 hot EM's to find that #1 is not joining in with the other kids. I haven't had any luck with the stomp test to double check the code that was thrown.

Here is a link to my previous attempt at overcoming this latest hoop that I need to jump through. http://www.bimmer.info/forum/showthread.php?t=35068

[Brandon J]

Hi,

I would like to ask a few questions and give a few suggestions. I hope we can help you with your problem.

If you say it is rain water then I will go that route. I have seen BMWs with bad seals to the computer and a new computer was needed. So lets hope it isn't that. If #1 cylinder isn't firingl, then try switching the coil to another cylinder to see if the coil is bad. It is common for a direct coil (as on the M50 engines) to go bad and take a computer with it. It does happen and there are people who were lucky and did not need a new computer. The other thing I would check is to make sure electrical connections don't have dirt and spray with electrical contact cleaner or WD40 to remove any left over water. A hair dryer can work too for a no-chemical solution. Make sure your hood seals are on correctly and double check they work. If it still rains, from what you tell us, more rain gets in even while you don't use the car. That isn't good because you are not heating the engine up to get rid of any standing water. In the mean time, protect the engine bay.

Questions:
Describe how the car starts.
Describe how it runs on idle, cold, warm.
Describe how the engine behaves when blipping the throttle, when pushing it and letting the revs go up a little.
Have you checked the battery voltage? (low voltage can make computers act weird - and even throw a computer code)
Have you ruled out a bad injector?
What happened with the washer hose?
Any pics of the #1 spark plug compared to another cylinder's plug?

Good Luck.

[ryan roopnarine]

leaking fuel injector will cause a misfire, as well. with the age of your car, your coilpacks are probably packed with tiny hair cracks that allow the juice to jump to the valve cover at the slightest provocation. you should confirm that the coil has a passable resistance, and try switching it out onto another cylinder. i have a box with 5 or 6 coils and 2 fuel injectors, as well as a MAF and other crud. if you would like to borrow anything, feel free to ask.

[ericbendler]

I have switched the ignition coil out and it it still #1 not running with another coil pack over it.

My hood seals seem like they are good.

Car starts right up with a noticeable stumble.

Upon throttle it stumbles and sounds like its missing.

The previous water in the cylinder episode took place after rain and was #5 & #6. The two which are a lot closer to the rear of the engine bay (right by the hood seal).

Seemed conspicuous that this time it was #1.

Washer Hose?

[ryan roopnarine]

you might probably want to actually check n.1 to make sure that it isn't sparking, either by taking the coil out, grounding a plug, and having someone else confirm that the pack is not sparking at all, by hooking a vom up to the coil connector with the engine running, or by disconnecting the coil from the harness with the car running to see if the idle degrades. i've had to replace fuel injectors on two separate occasions because they were drowning out spark.

as to #1 getting wet. i've had all 6 get filled up when i parked the car up for a few months.

[ericbendler]

What do you mean n.1?

What is a vom?

You are encouraging me to continue to check the ignition coil?

"s to #1 getting wet. i've had all 6 get filled up when i parked the car up for a few months." is something that a couple people viametly denied in my last thread on this problem. Good to see that I am not the only one who might be having rain water issues.

[Brandon J]

What do you mean n.1?

What is a vom?

You are encouraging me to continue to check the ignition coil?

"s to #1 getting wet. i've had all 6 get filled up when i parked the car up for a few months." is something that a couple people viametly denied in my last thread on this problem. Good to see that I am not the only one who might be having rain water issues.

Ryan is saying to use a Volt Ohm Meter to check that there is an electric current and what the resistance is in the coil. Since you already switched a coil pack, then check to see there is power going to the coil. As Ryan was saying, you can take the coil with plug out. Rest it against the engine so ti can spark. If you see spark, then you ruled out a faulty iginition to cylinder #1. Just because you had water in 5 & 6 does not mean this is the same problem. If the spark is good, then the next thing to check is the fuel injector. So, now you have the first thing to check and rule out.

[ericbendler]

Why don't I just replace the fuel injector for #1? I will have to wait until Tuesday to have some help with being CERTAIN that there is spark going to that cell.

Thanks for the direction in making sure that I have spark. I am going to check that spark is being delivered via your method on Tuesday.

[ryan roopnarine]

i don't mean to badger, last time--i promise, but if you need a FI to test with i can certainly leave one in your mailbox tomorrow or such.

[ericbendler]

Why don't I just replace the fuel injector for #1? I will have to wait until Tuesday to have some help with being CERTAIN that there is spark going to that cell.

Thanks for the direction in making sure that I have spark. I am going to check that spark is being delivered via your method on Tuesday.

[ericbendler]

I would really appreciate having one to work with. Thanks!

Who knows...after checking the DME, all seemed well with the seals so far as rain water would be concerned.

[ryan roopnarine]

i don't remember your address. if you pm it to me, i'll have it to you after 3 or so.

[ericbendler]

I would really appreciate the injector. Your PM is full so I needed to send the message here.

The HD on my desktop has crashed since you brought that file on PDF. Do you think it would be pushing it if I got another copy off you?

Thanks. With the combination of the fault reader and the Bently, I think I can do a pretty good job keeping it out of the shop and on the road.

Anytime you need to use the code reader, or wanna clear your codes, just let me know.

229 NW 16th Ave.

[ericbendler]

Let me say first that I don't even remember what it was like to drive my e34.

Ok. I have replaced the following parts (in this order) to see why my car won't run #1.

Switched out ignition coil #1
tried another fuel injector
swapped ECUs
replaced the battery


I have not checked the voltage at the DME relay yet, as it took me a while to research where it was, but that is next.

I guess it is off to the import shop when I get my fin. aid.

I have spark, and the a strong start, but cylinder #1 won't run. (squirted water on 2-6 exhaust manifold. Water on #1 just sits there.

There is A LOT of black carbon on the top of the piston, but there is nothing for me to believe that its an internal engine issue.

I fixed my hood seal, and checked the fusebox.

Crankcase position sensor? Should I be VERY nervous that a mouse scurried away when I opened my ECU box the first time?

The code I get is "Control Unit Supply". I am thinking that I would have been better off going with CarSoft or something instead of paying $140 dollars for a Peake Code Reader that just spits out a code at me.

[ryan roopnarine]

anyone want to take a stab at this?

despite eric's having swapped out a fuel injector and a coil on #1, the car still appears to be dead on such. i probed the fuel injector rail with a VOM and found that the supply to the #1 fuel injector was either 0 volts or a steady .1 volts. all of the other injectors had normal .2-.3 variable voltages, as they were going up/down though the meter was not fast enough to determine such. when eric opened the dme box, a mouse ran out. short circuit somewhere in the harness maybe? i lent him my dme to try for 3-4 minutes max, as i figured that that short an exposure probably wouldn't fry it, even if there was a short circuit.

[Ferret]

I'd be pulling/inspecting all the loom that you can get at...

I got fed up of repairing gnawed wiring at my parents house a long time ago - the little buggers seem to take it on as a personal hobby. You may find it's tried to make a nest under your DME box and chewed through some rather vital insulation.

I'd be trying the following:
Disconnect both battery terminals
Pop your injector electronics rail
Unplug your ECU out of it's hole in the DME box
Test resistance across all the injector plug terminals - not the injector itself, just the wiring

You'll know if you've got a short as while the dme is out of the loom all the injector wiring should be open circuit - if you've got one that's showing a circuit with resistance you know you've got a short in the loom...

[BigKriss]

what, you mean like mickey mouse?


............. when eric opened the dme box, a mouse ran out. short circuit somewhere in the harness maybe? i lent him my dme to try for 3-4 minutes max, as i figured that that short an exposure probably wouldn't fry it, even if there was a short circuit.

[ryan roopnarine]

yeah, like a real mouse. the thing that everyone in florida is employed by. the mouse in question was smaller than this, iirc.

http://z.about.com/d/exoticpets/1/0/D/9/1/mouse2angelo.jpg

[genphreak]

anyone want to take a stab at this?

despite eric's having swapped out a fuel injector and a coil on #1, the car still appears to be dead on such. i probed the fuel injector rail with a VOM and found that the supply to the #1 fuel injector was either 0 volts or a steady .1 volts. all of the other injectors had normal .2-.3 variable voltages, as they were going up/down though the meter was not fast enough to determine such. when eric opened the dme box, a mouse ran out. short circuit somewhere in the harness maybe? i lent him my dme to try for 3-4 minutes max, as i figured that that short an exposure probably wouldn't fry it, even if there was a short circuit.Did you run a new wire to #1 injector?