I have a 72 with the surging accelerator problem. I got a new bellcrank and throttle rod so I could perform this modification.

I'm not a welder and was wondering how anyone else has done this mod without welding? It looks like I can use my Dremel and saw the arm off the weld but I'm not sure how I would attach a washer to the bellcrank. Attaching the arm to the washer I can see, but I don't see what I would screw to with the washer.

Any ideas?

You are certainly on the right track.......the throttle surge thing is a common issue. I believe it's a combination of increased tolerances (from regular use) and the angles of the lingage relative to the bell crank. When I was redoing my 1970, I had quit a bit of slop where the rotating portion of the linkage bears against the bushing at the rear. I actually rebored the bushing so it was concentric and then welded on a sleeve over the existing end of the rotating shaft to fit the rebored bushing. I ajusted the linkage as far as I could to get as close to the angles you read about in the article on this problem. Finally, I insured all points on the linkage, that move or bear against one another, were lubricated.....the end result was a very smooth and almost linear throttle responce. Note: I did not have to modify the bell crank to accomplish the task. One last thing to check are your engine mounts. If the drivers side is shot, the engine will lift and effect the throttle linkage. Hope the helps you out a little!

Tom

...the rotating portion of the linkage bears against the bushing at the rear...

aaah! watch out for those linkage bears. they'll bite your fingers off!!

haha, anyway, Tom's on the right track. I've also heard of bending part of the linkage to get the geometry straight, but I have no idea how to describe it to you.

Thanks for input Tom. I plan on lubing the linkages as well as doing the bellcrank. I may just take the bellcrank pieces to a shop and let them weld it into position.

I hope my motor mounts are good. Thanks for that tip!

I think the bend you are talking about Jason is on the carbs and it you have to get a longer rod and "bow" it to fit. That probably would have been cheaper than the bellcrank but I'll give this a shot.

I've heard of using a latter rod from a 280 or so (going by vague memory here) and that it already has that bend in it.

2¢

E

I've heard of using a latter rod from a 280 or so (going by vague memory here) and that it already has that bend in it.

2¢

E

i think that's the one that I was thinking of. and yes, the other way involves a longer rod and bending it. that's really the pity with lever-based throttle systems; the geometry can bite sometimes.

Well, I got another bellcrank and linkage rod and attempted this mod. I sawed off the top bellcrank arm and used some JB Weld to re-attach it in the new position. Unfortunately the arm was a little off when I clamped it so it dried tight a little offset so the top bushing won't fit.

I guess I want to try the "hockey stick" fix as shown in the picture. This seems to be a much easier fix and I hate paying for another bellcrank. I did relube the linkage and it improved very slightly.

I think the rod is from a 280ZX. Not sure if a 280Z would be the right one but if anyone knows for sure please chime in!

I'd like to get my hands on one of these rods so if anyone has one they want to part with please pm me. Thanks!

As a thought I was going to suggest getting a length of all-thread to replace the rod, when I remembered that one end of the existing rod is left handed thread and not right hand.

So, as an alternative, what about a section of tubing, preferably steel for strength, that has an inside diameter equal to the diameter of the rod. You would cut your rod with a pipe cuter to avoid a sharp and flared out edge, then fit a section of the pipe to lengthen your existing rod by the amount required. You could also pre-bend the pipe to fit the required radius bend, then cut and fit the rod. Then either solder or braze the rod/pipe together or if not able to do that at least crimp the pipe onto the rod and use some of your JB Weld.

Just a thought.

E

That is a good suggestion but I would have to thread the piece I attached so that I could screw the plastic connector back on. I also don't want to adapt my rod and have no backup so I would want to get another rod anyway.

Unless I can explain it to a parts place or find someone who has one here I may be doing just what you say. I don't know the ZX's at all but I looked at a picture of a 280ZX motor and I saw the rod connected to the linkage towards the front of the motor.

Getting the other rod is a good back up.

What I meant about using the pipe, is that you would cut the rod and insert the piece of tubing to lengthen the rod and would insert both halves of the original rod in to either end of the tube. The original threaded ends would still be there for the plastic ball connectors.

FWIW

E

Ok, that makes sense. Thanks! BTW, that JB Weld seems really strong.