Kevin Baker

Has anyone heard of a part called the ignition conrol module, or the transistor ignition unit?

It is listed in an old Auto Atlanta catalog under ignition parts. The Porsche Part # is 928 602 706 01.

I think this may have something to do with the intermitant stalling problem I have been having.

Any help?

Luis de Prat

AFAIK this part is exclusive to the 944 S and 944 S2. Indeed, it does cause severe hesitation and bucking when malfunctioning, but I'm not sure whether there is one on your car.

Easy to locate: triangular shaped plate bolted onto the inside of the driver side fender, next to the A/C dryer bottle.

Dave951M

Have you checked your fuel pressure? Could be the cause of your problem.

Kevin Baker

Bump....Louis, you are probably correct as I did see the AC dryer, but thats it. Is it above, below, behind the innerfenders by the marker lights or something?

Anybody know where this thing is, assuming that all 944 have them?

AFIK if a 928 uses 2, one to control each cylinder bank, ours SHOULD have one.

Luis de Prat

Hi Kevin,

You should see it quite easily. It's mounted on a bracket smack next to the dryer bottle. That is, if you're facing the car, it'll be to the right of the bottle, on the inner fender, below the coolant expansion tank.

I doubt your car has one if it's not a 944S/S2.

Good thinking, though, because that was one of the toughest fixes to diagnose on my S2 when I bought it in 1999 and it kept crapping out for no apparent reason!

rcldesign

If I'm not mistaken, the part you are referring to is an ignighter. You can get them from BOSH (OEM), but Nology, and a bunch of other companies also make "high performance" versions of them.

Kevin Baker

Luis-Thanks I'll check that out when I get home.

Any 944N/A folks ever heard of it?

SidViscous

All 944's should have something that does the same thing. Even if it's only a circuit within the DME.

Having said that, having experienced similar problems and having seen a variety of other people having similar problems recently, and it being the same thing in many cases. Check the coil. A replacement is cheap, though replacing it can be a little bit of a PIA.

Kevin Baker

Sid, thanks for the response. I have the coil and other assorted parts at home, garage is starting to look like a Bosch warehouse with all the yellow boxes around.

JLeake

On 944's without a separate ignition control module, like my '86 951, the transistor that fires the coil is located on the DME. Over time the solder joints can crack and give you an intermittant stalling problem. The car will run fine and then all of a sudden behave as if you turned the ignition off. A temporary fix is to keep a stick in your passenger compartment. When the car stalls, whack the passenger floor board. This is of course just to get you home. You really need to fix it (if this is your problem). Good news is it's an easy, cheap fix. You take apart the DME and look for the largest transistor. If the solder joints have little cracks, you've found your problem. Heat the solder joints with a low wattage iron (~25 watt) and use a solder bulb to suck out the old solder. Re-solder, and throw your stick away! I bought everything I needed from Radio Shack for like $15.

Bryan

I would not be surprised if it's your ECU. As the others have stated, that ignition control module is only for the 16-valve cars.

I had an intermittent ignition cutout as well in my '88. It was the ECU. The car would run fine, the suddenly it was like someone shut the key off. I ran the whole DME test plan, all the inputs to the computer checked out, I used an oscilloscope and everything. Power and ground to the computer were fine too.

Two of the best diagnostic tools you can own are a fuel pressure gauge and a timing light. Put the fuel pressure gauge on, and put the timing light on the coil wire, and start the engine. If it quits reliably (is that an oxymoron?), just wait for it. Watch the timing light and the fuel pressure gauge and see what happens.

I'd also scare up a known good ECU to try out.

Bryan

Kevin Baker

J-I took the DME out last w/e and didnot see any "large transistors" or any cracked solder joints. When you say large, how large are we talking?

JLeake

I wish I had my digital camera with me when I did the repair so I could show you. From memory the transistor is a metal cylinder about the diameter of a nickel (I think it has mounting tabs on the sides of the cylinder). It's probably about 1/4 tall. It is mounted at the edge of one of the boards. It has three relatively thick leads coming from it. As I recall, the leads make a 90 bend and then of course terminate on the board. If you have the DME out already you might as well resolder it just to be safe. As others have mentioned it's a good idea to install a fuel pressure guage. I got mine from a local hose supply house for like $12 with all fittings (I borrowed a tap).