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Where is ECU in '85 Golf?

Hi, Can anyone point me to where the ECU is on an '85 Golf? I've looked near the fuse box/relay panel and in the engine compartment. Bentley points to somewhere on the firewall, but nothing obvious in engine or passenger compartment. Is that it on top of the air cleaner? I want to check/clean the connector.

I'm trying to diagnose a chronic stalling problem. It just dies when rolling to a stop, othertimes when just driving along. Sometimes I can start engine immediately, sometimes have to wait 5-15 minutes and it'll start fine and run fine for days or weeks before next stall. Car has

283,000 km on it. Based on tips in this newsgroup, have changed fuel pump relay, transfer pump, fuel filter, ignition wires, and rubber boot on air duct just ahead of throttle. Have checked cap, rotor, plugs, and Hall sender wires inside distributor. Have cleaned up and put diaelectric grease on all connectors I can find in engine compartment and at fuel pumps. Have checked/cleaned grounds in engine compartment and beside fuse panel. Have checked state of wires from fuse panel to both fuel pumps. I haven't done a main fuel pump delivery test yet, that's next. We use name brand gas (Chevron, Esso, Shell, PetroCan) and refill at 1/4 tank. Alternator and battery check out ok. Engine runs fine otherwise. I'm running out of ideas.

Thanks.

Reply to
tonyw
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there's a pic of one on this page..........at least you know what it looks like.

try inside the car up under the dash, maybe the passenger side.

Reply to
Harry

I doubt it is the ECM/ECU. :-) AFAIK The ECM can be found if you open up the engine hood and stand on the left side of the vehicle where the windshield wiper motor resides. So you will find it close to the windshield under the ign module which might be under a plastic cover. Pull up the rubber strip and then that cover. At least that is where I think it is on your 85. You can always follow the wiring. ;-)

Hmmmm since you said you clean all or most electrical connections, and your FI is not that complicated.......... ......here are my thoughts and especially if the tach drops to '0' when the engine dies while you are driving it or the idiot lights dont' light........... Sometimes the ign. switch is faulty and may or may not work. I guess I would purchase a new one and then you can easily try it out the next time it stalls. You would only have to remove 2 phillip screws and unplug the ign switch plug and install on new switch. Then turn the new ign. switch with a screwdriver. What happens to the inside of these switches is that the metal contacts heat up and the springs that keep pressure on them lose their tension or springiness. I have rebuilt one to see if I was correct and it lasted another year. I replaced with a new one when my fixed one started to fail.

8^)

It could also be the ign. module getting hot too. You can find one cheaply at one of those U-Pull-It places. I have only had to change 2 of these during the years on different cars.

You need to determine if it is a FUEL problem or an IGNITION problem. I vote for an ignition problem.

Good luck!

Reply to
One out of many daves

Hi Harry and Dave, Thanks for the pointers to the location of the the ECU and what it looks like. Checked Bentley again for "ignition control unit" and it should be under the drip tray on the driver's side.

Regarding the ignition switch, the idiot lights stay on though when the car dies, does that disqualify the ignition switch? The ig switch is a possibility though after 20 years of use.

Thanks!

-Tony

Reply to
tonyw

I vote fuel, but I am not knowledgeable on this area. I have had the symptom, so I will be very eager to learn the cure in this case.

The work around is to keep the revs up a bit while braking. In the old days, I would suspect a bad dashpot.

Reply to
Tom's VR6

Hi, thanks for all the tips, I uncovered the Ignition Control under the drip tray near the left hand hinge of the hood/bonnet as described. If I found the correct item, it had a footprint slightly larger than a box of wooden matches, held by 2 screws to a heat sink. Surprisingly, given it's location, the unit and plug were very clean. The connections looked good too and the dielectric grease was in good shape, not hardended up.

Is there another "brain", an ECU, in the '85 Golf or is the ignition control it? I believe it's a CIS engine.

Reply to
tonyw

Oh and I did have a Jetta with a similar problem. The terminals to the main fuel pump were slightly loose/large and the electrical connection would get lost some of the time. Usually this would happen while trying to start the vehicle.

Relay or fuse for the ECU? And I will ASSuME that you have checked that NEW fuel pump relay and it's receptical. 8^o

good luck, dave (One out of many daves)

Reply to
One out of many daves

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