I was working on my car last night and when I took off the cap and rotor I found this.



It's tough to see, but one of the lower tabs that points up from the bottom was bent back and away from the distributor, and one of the inner tabs that rotates with the distributor was pushed in and it was bent to the side. It's front and centre in the photo.

I've only owned the car since last fall and I was having a minor driveability issue. It would drive fine under hard acceleration but in low speed cruising it would miss/stumble and the tach would bounce. I would like to think that this is the probable cause of that.

I cleaned it up with a wire brush on my dremel. Checked the electrical connector on the pickup and the pickup itself, both look good. I also removed the ICM and cleaned the bottom right up, cleaned up the mounting bolts and the metal mounting tabs on the ICM and put on fresh thermal paste and put it all back together.

After that I bent the damaged tabs back to where they looked right when compared to the others and rotated the engine by hand to make sure there was no interference. I was able to more precisely align them with my pliers by rotating the engine until they were right at the tabs and I think I have it to where everything is as it should be.

The car has 73,000km and I believe it's the original distributor, although it did have 2 different plugs in the front and rear banks of the engine, aftermarket wires and aftermarket distributor cap. I am replacing all of those right now.

Here it is in the process of cleaning it up with the tabs bent back to where they should be after checking for clearance. After cleaning it a little further to the best that I could get it and rotating the engine by hand I now have the new MSD red cap and rotor installed. I'm new to distributors, this is my first time opening one up so I'm learning here.



My questions are:

- What could cause these tabs to bend like that in the first place, a bad bearing somewhere? Was it seized in place from sitting and bent when it was started?
- Should my "fix" by bending them back be ok and hold up?
- Is it possible that this was causing my miss/stumble?

Sounds like both pieces might have come together at some point.
Is the shaft tight or does it have some play in it?
I had trouble with my car not starting and dieing occasionally and it ended up being the mounting of the pick-up coil.
I had changed it out but on my distributor the pick-up coil just kind of floated and wasn`t really mounted solidly.
On the new distributor I installed the pickup coil is mounted on a bracket with screws.

[This message has been edited by TXGOOD (edited 03-28-2013).]

quote Originally posted by Ry86GT: - Should my "fix" by bending them back be ok and hold up? - Is it possible that this was causing my miss/stumble?

Wow! That the car ran reasonably well speaks volumes as to how well and simple the stock system works. Yep your miss and stumble is likely caused by this.

Now that you've got them bent back to where they belong, I'd call it good and see if its running OK. You'll probably find its much improved. Just don't bend the "tabs" again - the metal has already been stressed once and straightened. Bend it again and it will probably break.

You could just bite the bullet and buy a new distributor if you'd rather. Might be worth it for the piece of mind. The new ones feature a much more robust design for the magnet and pole piece and some here have claimed their car idles better with the new design.

No idea what might have caused them to get bent like that. Maybe a previous owner using something to pry off a stuck rotor?

The shaft seemed tight from side to side. It did pull up a slight amount when I was trying to get the old rotor off. It wasn't far, and it rotated very slightly when that happened - my guess is this is due to the gear at the bottom of the distributor. Sorry I don't know the names of the parts.

I wonder if the lower tab was pushed on, either on purpose or by accident, when the last cap/rotor change was done and the damage wasn't done until the engine was started again. The metal was so easy to bend I bet it wouldn't have even made a sound and the previous owner drove it so little I'm not sure he would have even had it looked into. Also like I said the car did run and was driveable, just had the annoying stumble / miss under the right conditions.

This is by no means a DD, so if it "should" work then I am going to finish putting the top end back together and see how it runs. If it continues to stumble/miss I will look into replacing it at that point. I don't want to sound cheap, but I don't want to spend any money that I don't have to spend.

Truth be told I was a little shocked when I got the old cap off, but in an odd way I was happy because I thought I might have found a good possible candidate for my miss/stumble. When I bent the tabs back with the pliers I was nervous of it breaking so I got it as clost as I could in one shot, then rotated the engine so the tabs were agains each other and lightly tapped on them to fine tune the adjustment. I was very happy that the inner tab in particular didn't break off when I bent it back. It was at a pretty tight angle.

I've seen photos of the revised design. It does look much stronger/more durable. I was happy to see that the ICM was a GM unit so that wasn't played with at all. As I said before the pickup coil appeared to be in good condition, just a bit dirty. The wire terminals were perfect and there weren't any breaks in the insulation on the wire leads of the coil.

You can get a reman Cardone distributor for $120 or so at Auto Zone.

If the distributor ends up being no god I usually have a spare one in the garage from stripped down 2.8 I have junked. Dan

Thanks for the offer Fieroflyer. I'll try and get her started up this weekend and see how she runs. I still have to finish putting everything else back in too before I can try to spark her up.

This is a bit OT, but where in Ontario are you? I'm in K/W area.

[This message has been edited by Ry86GT (edited 03-28-2013).]

North west of you up on Lake Huron in a little town called Southampton. Dan

Ahh I know Southampton. My Grandma lives there, I used to roam around there all the time when I was younger with my brothers. Beautiful area.

I'm sure I'll be taking a cruise up that way at some point this summer :-)

I suspect you indeed found the cause of your engine "stumble".

I think you did good. Let us know how she runs when you start her up.

Here's my old distributor. The car would quit after driving about 40 minutes. Then it quit altogether.


Here's the replacement. I'm not sure how good the replacement is, but it fired right up when I replaced it.


The cool thing is that the pickup is replaceable without removing the distributor

[This message has been edited by CodeSlinger (edited 03-28-2013).]

quote Originally posted by CodeSlinger: The cool thing is that the pickup is replaceable without removing the distributor

I've seen that mentioned here before but could not figure a way to do it without removing the distributor. I have one just like your picture, but admitedly I got it out of the junkyard so maybe its not exactly the same as yours. I had to pull the shaft out to replace the pickup coil.

There's 3 screws (you can see 2 in the pic) that I believe will allow the part over the pickup to come off the top. But I could be wrong...

[This message has been edited by CodeSlinger (edited 03-28-2013).]

quote Originally posted by CodeSlinger: There's 3 screws (you can see 2 in the pic) that I believe will allow the part over the pickup to come off the top.

I think you still need to remove the center shaft and pry off the spring clip. Here's how it looks once the center shaft is removed: