ToreB

Just to clarify, "Pcar SBA" made a copy of the porsche memory module, and fitted it to his hammer. He did not make a homebrew diagnostic unit. The closest you get to a custom made Porsche diag system is probably the engine management system in the 964/993. As far as I know, there's only a handful of systems that can do all the OBD-connected things in our cars. (Motronic, ABS, air bag, alarm and climate control) Jennsiken diag tool. Here's the Porsche 964 compatible tools available:
The Bosch Porsche "hammer" (KTS 301)or later Bosch Porsche tools as PST2, KTS500 or PIWIS
Freeware Rennlist Scantool Windows software (serial port adapter as the T-OBD needed)
Durametric Windows software with a proper serial cable
Jenniskens OBD UDT/PDT999 diagnostic tool

Cheers,
Tore

JasonAndreas

What else is missing from Doug Boyce's software besides cycling the diff locks?

dhc905

Car was dropped off this morning. It was acting up on the 1.5 mile drive over there (after I swapped one, but not both distributor caps) with a more randomized CEL that stayed on for longer periods of time.

Hopefully new wires, plugs, caps, rotors and coils will resolve the issue!

Rocket Rob

Fingers crossed - hope this solves your problem. Keep us posted.

dhc905

Thanks Rob. I got a call last night and he said car should be ready today or Friday but that he himself was heading to Austin for a race (Lamborghini's). He said they did a compression test and all cylinders came back fine - 150's plus-minus. Not sure why they did that, but guessing it's a "while you're in there" when you have the plugs out?

Anyway, good news so far. Final determination should be coming out today.

jimq

The last update that I got on the scantool was the codes for the TIP. Has anything else been added in the last 5 or 6 years? I have the original scantool that I put together using the board that John in the UK use to sell.

ToreB

Among other things, I have added fault codes for all CCU versions in both 964 and 993 Scantool files. ANy faults from such units would otherwise be shown with number and "Unknown fault code".
Cheers,
Tore

dhc905

Got a call yesterday that the car is done. He said he cleaned up the engine bay some by removing the sound deadening and tying cables and such things down. He didn't make mention of the CEL, so I'm **VERY** hopeful that it got resolved.

He did try to put in some washer fluid (that's the only error light besides the convertible top) but he ran into the same issue I did - my new tank (located in the frunk) apparently needs a gasket or something and all the fluid leaked out.

But neither here nor there.

Will pick up tomorrow to confirm!

dhc905

Got car back - modderman (and Bill, a retired 964 owner who "volunteers" there) did a good job doing the requested work as well as additional maintainence items. Total labor cost for the plug wires, plugs, distributor caps, compression test was $850. Other misc. work items and cleanup of the engine bay came out to another $150 for a total of $1k in just labor. They tested the coils and they were fine, so they didn't replace them with the new ones I bought.


Therefore, in total, parts and labor for plugs, wires, and distributors was about $1,400. all indications suggest all parts (besides plugs) were original and therefore last 108k miles and 27 years. Probably not the go-forward replacement schedule, but just FYI.

Unfortunately for RRob (although really just for me) CEL flashed at me on my way home. Before I take it back into the shop, I have a nagging suspicion it's a shockingly silly fix. I will update tonight when I have a chance to address....

EDIT: when the wrench said he didn't notice any CEL, and then I did after about 5 minutes of driving off his lot, I for to thinking that the one difference was my Metromile being plugged into the 19-pin outlet. I drove to Costco to pick up supplies for a dinner party I'm hosting and as soon as CEL flashed, I pulled my Metromile and ****silence****. CEL off, has not come back on.

So basically I spent over $1,600 and really the problem the whole time was just my doggone MetroMile messing with the computer!!!

Rocket Rob

Congratulations at isolating the problem. What is a MetroMile and how does it connect to the car?

ToreB

The last information in this is very important. Connecting an off-the-shelf OBD device to the Porsche 964 could be problematic.
I do not know what 19-pin adapter you are using to connect to the car, but I guess a OBD diag device using CANbus or other modern signals on OBD2 interface pins could interfere with the 964 diagnostic circuits. The 964 had a very early OBD implementation, and have circuits connected to the diag port which is very different from modern cars.
Cheers,
Tore

dhc905

I think Tore hit the nail on ethe head. The Metromile is the connector to my 19-pin OBD port that logs my mileage and other basic stats to bill me for miles driven. It has a basic diagnostic element as well (on my Cayenne it will tell you if there are any engine codes, for instance). As a result, I think it pings the system every 25 or so seconds (see original video, it was so consistent I could set my watch by it) at idle and that was triggering the CEL. Further to Tore's point, I had to buy an aftermarket OBD2 -> OBD1 exchange to make it work, otherwise the alternative is plugging into the cigarette lighter socket which was a PIA, especially given our non-uniform socket size.

Basically, my car is allergic to the Metromile

Good news is I should have a strong electrical system for years and years to come, and got a fairly clean bill of health for my engine!


I appreciate all the input from everyone on this thread; if you ever find yourself in the Palo Alto area, would be only fair if I bought you a beer!

JasonAndreas

You could trying disconnecting/isolating pin #15 (on the aftermarket connecter) which is used by the Bosch Hammer to illuminate the CEL. The DME ECU will also illuminate the CEL when the L line is interrogated but the metromile shouldn't be connected to that.

bweSteve

holy crap. this was an amazing thread to read. subscribed.
I had no idea what a metromile was either. sounds like a insurance device to monitor your miles, so you pay less for a car seldom driven.
wow. Thanks turtle (aka dhc905) for documenting your journey.
=Steve

HiWind

nice .... i think the issue is not knowing .. now you know why the CEL shd be easy to live with