C20XE ECU question

[JohnCh]

You may have already tried this, but I've found that a good approach to finding a DCOE expert is to connect with your local vintage racing scene.  The shops that focus on vintage race car prep often have a Weber expert in house or one they work with as needed.  

 

-John

[Croc]

Thats a good suggestion John - thats how I found my various specialists to handle my webers that are multiplying.  

[SanderGA]

I’m worried about getting this wired up right so I asked SBD about it and here’s the response I got. Sounds promising.

 

Dear Sander,

 

There is no need to worry, the system is the simplest possible to install out of all the systems we do. In theory there are only 3 important wires to fit.

 

1. The ring terminal goes to the chassis ground or somewhere earth on the body.
2. There are 2 x 12 volt feeds on the interface connector. One powers the coil and the other powers the ECU. These can be joined together and taken from the 12V feed that powers the coil on your current installation, or the ECU or to your ignition circuit whichever is the easiest.
3. The tacho wire which is green connects to the rev counter. There are various places on the car that this can be connected, but maybe the easiest place is on the back of the rev counter itself.

 

The CAN interface connector is purely there if you use the mapping kit to talk to it. Otherwise it is not used.

 

Hope this helps.

[SanderGA]

On the topic of Weber carbs, I called a guy who referred me to a guy who referred me to a guy who finally said, "Oh yeah I do that". So once I have my new ignition system installed, I have a place to take it to address the carbs. The key, as suggested above, was seeking people who are involved in the vintage racing community. I found the people using webers in the vintage racing community by sending an email to Pegasus Auto Racing. They sell Weber parts so I figured they would know who deals with webers in my area.  

[Anker]

There are good manuals available online on maintaining and tuning Webers. Pegasus will also sell you sets of jets to try and allow you to return the ones you don't need for a refund. I had a 2000-3000 RPM flat spot in mine and a set of bigger idle jets solved that problem. I didn't do it myself, because I have a shop that knows how to fix Webers a 1/2 hours drive from home.

[bsimon]

The crank sensor is Standard Motor Products PC439 or Motaquip VRC116.

Saab 9000 1994-1998. Saab part# 4227203

 

Might save a few bucks sourcing it at Rock Auto or Vato Zone...

 

For future reference, starter is Saab 9000 as well.

 

 

 

[SanderGA]

I got my new distributor-less ignition system installed. The complete kit was specified and supplied by SBD Motorsport. Total cost was around $1,400. Installation was very easy and consists of the following:

 

• Mount the new ECU. It's larger so tough to fit it in
• Cut a hole in the firewall for the wiring harness to run through because the plugs are big. A 1 3/4" hole is sufficient. Cover the edges of the hole to protect the wires.
• Run the harness through the firewall.
• Properly connect the wires on the wiring harness to the plug for the coil pack. Don't forget heat shrink and confirm you are following the right diagram. Just because it says Bosch doesn't mean it's right. Count pins.
• Remove the ignition coil but leave the wires in place. Connect the two 12V wires on the wiring harness to one of the old 12V leads that connected to the ignition coil.
• Replace the crank position sensor. Only two bolts but access is difficult. 
• Remove distributor, insert a plug for the exhaust cam if necessary and install the blank to cover the hole left by the distributor.
• Install coil pack.
• Run spark plug cables from the terminals on the coil pack marked "1 4" to the first and fourth cylinder. Run the other cables to the terminals marked "2 3"
• Plug the coil pack, 12v power source, and crank position sensor into the wiring harness. Note that I added a connector for the 12V power source.
• Connect the green wire to the tachometer. A resistor, or a new tachometer, may be required. I haven't connected mine yet. I lost the resistor they provided because it's so small
• Connect the grey wire to the shift light. If it's a small light, no relay is required. A large shift light requires a relay.
• Connect the ground. 

That's it. More detailed instructions are attached. I have a drive scheduled this weekend and will report back.

C20XE ECU Replacement.docx

[SanderGA]

Took the car to the mountains with the plan of doing about 1,000 miles with the Rennsport Dragon Rally. I had to abandon it because I strained something in my shoulder lifting myself out of the car.

 

But I got 300 miles in. Car runs much smoother with the new ignition system. The best surprise was that my MPG is up 5+ MPG. Couldn’t care less about MPG but that’s an extra 40 miles between fill-ups. 
 

I had the carbs rejected but the guy that did it didn’t seem to know what he was doing and I thought I’d have to do it again as it still ran rough. Since he leaned it out, I suspect that’s a significant contributor to the mileage increase. It runs so smooth now, idles nicely, doesn’t smell of gas, and never stumbles so I’d be crazy to touch the carbs.