Guys,
Here's a topic for open discussion that I haven't seen discussed here before.

As many have known over the years, I have a 1970 914/6 that I restored and upgraded w/a '95 model 993 3.6L engine.
As I was putting the car together, I bought a engine to chassis wiring harness from Patrick Motorsports to marry the engine and chassis together. The harness was a good quality product that went in very cleanly and easily. It was really a plug in installation. The only anomoly I noticed in it was a that it came w/a wired in OBDII access plug to read the DME.1995 is OBDI. I really didn't give it much thought, cause when everything went together, the car ran fine. And it has for the past 3 years now.
Flash forward to 2008. The car recently started running crappy after it warms up.
I now need to read the system to retrieve the fault code.
my question thus, how has you guys hacked into your system? I know that there are a lot of conversions here.3.2L's,964 3.6's,993 3.6's, and 993 Variorams.
here is what I have done thus.
1. I've been in touch w/PMS, and they are working to address this.No issue w/vendor.
2. I have used my scan tool to try communicate w/the DME.It won't communicate,because all modern scan tools are OBDII,1996 + up vehicles only.One error msg is ''can't communicate,engine may run but not be OBDII compliant.''Scanning option is out.
The only option I'm beginning to keep falling back on is a Porsche only dedicated software package from Durametrics that does advanced Bosch Motronic trouble shooting on ALL Porsche vehicles from 1990 thru 2008.It's about $700.00
this would require loading the software on a laptop, and getting a 1995 911 diagnostic access plug, and pig tail it into my wiring harness.
The only option i will not take is to hand the car over to a Porsche mechanic,and write a blank check.

Give me some out of the box ideas guys.

Ron

If you have no registration/inspection issues like having an illuminated MIL (as you shouldn't...) being able to actually clear the code is nice but not necessary, unless somehow the ECU is in limp-home mode somehow.

Just curious - does your engine have the Secondary Air Injection System ?

It would be best to gain access to the 1995 diagnostic data. Best would probably be to get that section of engine harness from a 911-oriented recycler and find out where the pins go (should just be 2).

A "Bosch Hammer" is a hammer-shaped code-reader that can read the Porsche-proprietary protocol used in the early cars. After you've got the port wired in, you don't need to write a big check to an independent mechanic with such a tool for repairs, but you'll probably need to be prepared to spend for an hour of shop time to have the technician (you might luck out and get an actual mechanic, but let's keep our expectations reasonable...) read (and possibly reset) the DTC's.

OTOH - a lot (not all) of what the DTC's tell you is instrumentation-related data that can be derived the old-fashioned way. Measure all the sensors and compare their values to nominal. Read the plugs. Watch the O2 sensor data.

It's quick and easy (and not often misleading, but it happens...) finding the DTC as the ECU percieves it and working -that- issue, but we used to fix engines before ECU's existed by coming back to basics.

I've done work with vehicle diagnostic protocols before but I haven't had the opportunity to work with Porsche OBD-I stuff, so this is probably about as far as I'll be able to go on this one.

Thanks for the tips Rich,

Here is where I think I'm gonna be forced into going.

http://www.durametric.com/

Thanks for the tips Rich,

Here is where I think I'm gonna be forced into going.

http://www.durametric.com/


I'm sure whatever is causing the car to run bad is going to come down to a fault code pointing in the direction needed to repair.

2. The secondary air unit has been removed.(unbolted and put on a shelf,no hack job done) According to Autometrics, it isn't needed anyway. So, it has been off the car since day one. Up to this point, it hasn't been an issue.

3. as for vehicle registration, in SC, the $24.00 registration fee would put tags on a motorized little red wagon if you wanted to.

4. If it comes down to it,and I think it probably will, PMS will more than likely supply the 993 access plug prewired, and tell me which wires to tap into to gain access to the DME info.

thanks,
Ron

I have the Durametric setup for my 95 993 engine. It does everything the Hammer does for much less It works great and allows you to not only see and clear codes, test different functions but also allows switching between the dual ignition systems for testing (something I asked for and they delivered)

Call and talk to Duram. He's a knowledgeable and very nice guy.

Thanks Paul,

My question to you is,if you are using a conversion wiring harness or not?,or if by chance you are, how is the harness wired to make the connections.


Ron

I'm using Patricks conversion harness and the Durametric cable plugs directly into his OBD1 port

Paul,

Just so I understand correctly.Your harness came w/a OBD I port? not an OBDII.
When they made up my harness, I did tell them my engine was a 1995 993 not a 1996. I ended up w/a OBDII plug.

So is your plug the round type as I understand the 993's had?

Ron

Mine came with a OBD1 port which would be normal for the 95 which is the last year of OBD1. It's a rectangular shaped plug

Well, now that the cat is out of the bag, so to speak ...

I ended up getting in touch with a local porsche shop that has a good reputation and the right factory tools.

I haven't actually taken my car there yet, but the plan is to hook it up to the system tester and then do a few dyno pulls with different DME chips.

My PMS harness came with the ODB1 plug and my check engine light has been quiet so far, fingers crossed.
Andy

PS: I'm getting a really good rate on the dyno pulls (mustang chassis dyno) and i was going to ask them if they were interested in extending that offer to 914world members.

Andy, you might hook up a WB O2 sensor before going.....

What makes you think i don't have one ???
Andy