joker2cv

My DME has a problem: when i turn on the key (lights on in the dash), the injectors starts to fire continuously!
So my cylinders became full of gas! I tried another DME and all is fine...
What's the matter?

Thom

For people in Europe, DME Shop 24 in Germany rebuild the factory DME.

Obviously the website is in German but they speak fluent English.

http://www.dmeshop24.de/shop_content.php?coID=7

PS : not affiliated.

CyCloNe!

ECU Doctors added to my Fav list

joker2cv

I was on the street and suddenly the engine shut off. When i tried to crank it didn't turn! So i pull off a spark plug and gas exit from cylinder!!
I brought the car at home and checked the injection and i discovered that what you read.

P.S: my car is a 944 Turbo S my88

Zeff

How often do the drivers go bad that were replaced? What are symptoms of bad drivers?

I had my ecu resoldered and cleaned up for like 40 bux at a tuner shop. I haven't had any issues so far but it's been a month now. I've read several threads about listers just fixing the bad solder joints and fixing issuses, I haven't read about replacing anything more than small stuff that can be purchased at radioshack.

I'd love more info.

joker2cv

All solder joint are ok. It's an electrical problem, like if the Ecu "reads" that is "time to fire" (injection and spark).

joker2cv

The engine would crank, but it cant't because the cilynders are full of gas!
It's the DME for sure, because i swap another one and runs fine.
I made a simple test to DME: i check for a static continuity between 14 and 15 pins (injectors output signal) and all DME ground pins, but there isn't; so the problem is only when it's supplied.
Should be a failed of Eprom (stock)?

ECU Doctors

Hi Joker,

I can think of 3-4 things that may be gone bad with the unit.

-Old soldering
-Bad drivers
-Bad resistors
-Blown tracks
-...

I don't think that it can be the Eprom. When Eproms are bad, you get rough running conditions (rich or lean) backfires, etc.

brokeand poor

I'd be extremely careful with ordering from ECU Doctors "aka Specialized ECU Repair". They advertise a 5 year warranty which is fine. However they deny warranty service if the cheap tape warranty seals are broken. Ok here's the "gotcha" on that. They put cheap decals on aluminum which doesnt hold cheap decals. Aluminum DME's gets hot and cold and the decal sweats off, or if your holder is an interference fit the decal literally shears away when you slide the DME in.

This was a real problem for me when they programmed the wrong VIN into my DME. Of course they could'nt figure out this was the problem until I took my BMW to a competent BMW Indy who could read my ECU and see the VIN's were clearly wrong. Costing me $500 to figure out the problem and then reprogam the ECU the right way.

ECU Doctors refused to be held responsibile even when they authorized my repair shop to scan the ECU. They refused to cover any expenses and then told my bank that I broke the warranty because the decals fell off. Then they asked for the DME back claiming it belongs to them, regardless of the fact their invoice says Repair and not Replacement. I caution anyone from using these people.

Dash01

FWIW, I reflowed the,solder joints on my DME with an $8 soldering pen kit from Harbor Freight, part no. 38593. Has 6 or 8 interchangeable tips, for fine work, and good heat for this job. YouTube for instructions on how to solder if you don't already know. You want to heat and flow just the solder joint, not the whole board, so concentrate the heat. Takes about a second to heat and flow a typical solder joint, so get on and off before heating up and frying the electronic gizmo.

I replaced the Bosch 1012 ignition transistor (silver drum-shaped thingy on the side of the computer, about the size and shape of 4 stacked nickles) with an ST automotive ignition transistor BU941, which cost less than $5 from DigiKey, an online electronics supply house. Those units now run about $3.50 each. Add dabs if heat-conductive grease and tighten the screws very snug and Locktite, to assure proper heat flow from the ignition transistor to the heat sink, thence to the aluminum chassis, for good heat dissipation. That 15 amp ignition transistor is rated to about 175 degrees Celsius, so it gets hot enough to fry your finger, and repeated heat cycles over 30 years take their toll on solder joints, etc.

Note that on the opposite side of the printed circuit board is another aluminum heat sink, which has heat-making transistors, so check on those and assure good solder and heat-conductive grease connections there.

Disconnect the car battery before removal of the Motronic, and ground the Motronic whlie working on it, just in case there may be risk of damage from static, etc.

Radio Shack or similar local electronics supply houses may have all this stuff if you don't wish to go through DigiKey or similar.

I'm no expert, but have re-flowed solder joints on about 6 cars, including my 951 and various BMWs, so far with no ill effects, and I fixed my Porsche 951 unit this way. Researching this topic on car forums, Google, etc. it seems the most common fault is hairline crack at the solder joints between ignition trigger and printed circuit board.

If the car cranks but won't start, cheapest and easiest diagnostic test is to slap (not hard) the Motronic while cranking, or, if running, slap it and see if that cuts the engine. If so, this suggests the problem is internal to the Motronic. However, crank/no start can be other suspects, such as fuel or main relay, CPS sensor, ignition switch, etc. But, given the easy and zero cost of the Motronic slap test, may as well start with that. Beats the Braille method of just throwing expensive but unneeded parts at the car...

mahoney944

That's a fair point, there are many cheap alternatives, and at $350 to do the DME, for a little more you can own the rogue ecu with all modern internals with convenient options if you ever decide to upgrade something later. If you're going for cost effective, soldering and replacement resistors etc is a better choice, if you're dishing out the money, you should upgrade to the superior unit, rogue ecu

ehall

Except the Rogue isn't taking any new orders for the foreseeable future.

fejjj

I believe you can order the ECU now.

mahoney944

Yes and no, from what I gather from his site description on the front page it looks like he's taking time off but as he stats, he doesn't plan on going anywhere. I suppose the point is cheap repairs now are a better option for when he does return. It fixes your current conditions while saving your wallet and allowing you to upgrade later. Sending it out fixes it too but it doesn't take its age away. The stock brittle components from 30 years ago will continue to fail even after a quality check up...which isn't peace of mind for me. Im not disqualifying this solution as I'm sure they are reputable and based on the ops results things look good but at 350 you could buy 2 used dme computers and as posted above, materials to fix them are cheap

Rogue_Ant

Still taking ECU orders - but currently on a 3 week or so build time...