MSD 8973 Issues

Went match racing over the weekend. On a pass, the car cut out and started acting all weird while on the throttle. Started unplugging things until the problem went away. It was the 8973. Put a normal chip in the box an made a pass and the car came alive. It must have been an on going problem.

I'm calling MSD on Monday. Anyone else having problems with this box? I checked grounds, power wires, pedal switch etc. everything is soldered.

Shannon

 

Shannon,
We had TONS of issues with our 8973, put a six shooter on there and it was perfect. From what I understand the box produces alot of noise, and if it's too close to the ignition system or other wiring, it will mess things up. I have heard of a few guys running them without issue, but meticulous wiring and mounting was the reason they worked for them. We had to send our mag in each time, as when the 8973 acted up, our mag was in need of repair. Another thing we noticed, is that if you put your computer on top of the rollcage and try to modify a setting on the 8973, our laptop would freeze up and "not respond". Not sure if it's the same case with your car, but that's what happened to us. We ended up with 3 of the 8973's until we realized it, not the other parts, was the issue.

Brandon Booher

 

What was the symtoms, I'm having an issue at the moment but had ruled out the 8973 because I disconected it and the motor was the same but maybe it has damaged the mag. The motor will not rev over 5500 and sound like its on the limiter, remove fuel it is a little better because i guess it is leaner and easier to burn the fuel. The coil failed so installed new coil and leads, went out and was the same. the 8973 is inside the car well away from the coil and points box and uses the msd sheilded cables. 2 step works perfect but when i release the button the motor climes to 5500 and that is it and it destroys the oil. I have a spare mag I will try with the 8973 disconected and see what happens if it is okay i'll reconect the 8973 and see if it plays up again.

 

Our major issue was either the car would run like complete garbage (no pull at all anywhere on the track), or it would pitch the belt. When it pitched the belt the plugs looked brand new, so it was obvious it wasn't a fuel issue.

Brandon

 

Called MSD. They said I am the first one they have heard of with problems. I know this is BS because serveral people from the St Louis div race had the same issues. They want to check it out so I guess I have no choice but to send it to them.

 

We are using the standard roller switch on the clutch to apply 12v when the clutch is pressed. We've been runnin this unit since March. We have actually never ran the car without it. But having paid several tuners to come in, they all don't understand why the power is down on the car with all the latest stuff. We've re-degreed cams, checked TDC, changed mags, coils, boxes, camshafts etc. Jumped compression way up etc. to no avail.

Mag, coil, points box is on the right side of the chassis. Everything for the 8973 is on the left side. Everything is soldered and I mean everything. All wires are shielded with spark plug sleeving. The only thing we are running off of the box is the shift light and the rev limiter. We use the powermaster 12v battery and it was fully charged. We also use the 12v noise filter that provides a few seconds of power in case of a voltage drop. Everything is wired exactly how the instructions show. It doesn't specify gauge of wire, but we used bigger wire than was on the box itself to run switches.

I actually believe that outside signals might interfere with the box. We were at a pretty small track and it was cutting out. I have had 4 other drivers in alcohol tell me to get it off the car, but i didn't believe them because it was new. I think something like a radio or cell phone signal can interfere.

After unplugging everything one at a time, it simply idles like crap with the box plugged in. First pass yesterday with the box, the car under power tire shook horribly on a really bald track.

Unplugged it from the mag and replaced the plug in the side of the points box with a 10400 chip to try and the car blew the tires off 3 different times in the run.

We knew we were down on power but couldn't figure out why. We have been bandaiding it with gear ratio. Your mouth would drop if you knew how much gear it took to move this car with it down on power.

 

On a side note, we have also been pulling fuel away from it to get the plugs to show heat. They have been in the 4 range. (down the strap and halfway around the base of the plug). When running without the 8973, it burned the plugs all the way around and down 2.5 threads. Between the two passes, there wasn't even a pill change.

 

msd

We've used this box since it came out. Run a hemi-lencodrive in Top Dragster. Had one issue at
norwalk 2yrs. ago, but the msd guy helps us in the right direction. we had the start retard on by mistake and blue wire malfunction. We just raced at canada, made a new timing curve to get down the new surface. Also, do you use the msd ignition tester to run the set-up on your laptop before even starting the engine? This is a must do!

 

Yes, we have the tester, and have had several people look at how it is wired. The unit must not be very durable. We wouldn't have found our power issue if it didn't start cutting out. As I stated above, we paid several tuners to come in and help on the car. Our setup is very common and it had them scratching their head. It is hard to place the blame on the latest technology, but with building a new car we didn't want to waste money on the old air timer stuff. Live & Learn........