Aggressive throttle

[winstonsmith]

So the torsion rod is in backwards? Is there any play between the rod and the hole it goes in? Mine wiggles back and forth. Seems like there should maybe be some kind of rubber washer in there or something.

Anyway how do the plastic ball joints come off? Do I just pry them off? I was afraid they might break. I want to disassemble this whole thing and clean it up.

[kmack]

Yes, the plastic ball joints just need to be pried off. A good flat-head screwdriver works great. When putting mine back together, I used a little Lithium grease inside the ball joints and on all the shafts. If you have any type of corrosion of rust on the shafts, take some emery cloth or a somewhat fine grit sandpaper (200-400 grit) and clean them up. Especially on the bell-cranks shaft on the firewall.

[2-4-T-Z-MAN]

This might be an easier fix for what is being discussed.

Flip the linkage at the firewall. Notice that the rod coming out of the firewall is attached to the short portion of the linkage, with the long portion pushing the carb linkage. By reversing that one bit of leverage you will have better leverage for the carb linkage. No cutting ,no welding.

[EScanlon]

This might be an easier fix for what is being discussed.

Flip the linkage at the firewall. Notice that the rod coming out of the firewall is attached to the short portion of the linkage, with the long portion pushing the carb linkage. By reversing that one bit of leverage you will have better leverage for the carb linkage. No cutting ,no welding.

I'd like to read about the results if someone tries this.

What I know about levers and pivots is that you would be reversing the "throw" of the lever.

Stock position would require a short push/pull for a longer pull/push.

Think of those model air planes on a control line. The distance your hand travels at the end of your arm is a very short distance in comparison to the distance the airplane flies.

By reversing that, now it is your HAND that needs to travel the distance, while the plane gets to move a short distance. Translating this back to the car, is that you will now require a LONG push/pull for a SHORT pull/push. How this will affect the car's behavior is what I'm interested in finding out.

My thoughts are that it would restrict the rpm's to a given "window" simply due to the limitation in the throw. (i.e. only allow 500 to 3.5k or 3k to 6k, simply because the set of the throw at "idle" and "wide open" is such to only allow that much adjustment.)

So, will someone try this and get back to us?

Enrique

[winstonsmith]

I don't know why or how but in that third picture, the torsion rod is installed backwards. The one that connects the back part of the linkage to the front should go in through the top of the opening. Seems to me that that would cause it to bind. I'm taking a picture of mine as we speak to show what I mean.

Now, compare your picture to mine.

I checked my repair manual and it has the torsion bar the same as yours so yeah mine is upside down for some reason. It doesn't get in the way of anything though. It still has full movement all the way around if that's what you meant by it possibly binding. I have no idea why the last owner would have out it on upside down. I will probably put it on the normal way after I finish cleaning the whole thing up. Thanks for that info. I didn't even realize it was on wrong.

[2-4-T-Z-MAN]

Winstonsmith,

Your cars last owner did what I'm talking about.

Looking at picture #1 above shows the linkage as it is on my car. I did the adjustment on my car some 20 years ago at the advice of a mechanic friend. He happens to race Datsun's and builds the cars he races. The only thing I neglected to point out is that I straightened the lower pivot point that attaches to the gas pedal linkage just slightly. I may have had to adjust the linkage bars also to allow for total travel. Made excelleration smoother with no loss of RPMs,

[Murph]

I'm another one that had this problem. I'd previously played with linkages and such with little luck. However recently a mates dad was playing with my carbs (due to another problem) and messed with just about everything there. Now that it's all back together as it should be, the sticky throttle problem is gone. I noticed that the rest position of all the linkages is slightly different now. I'm guessing the problem is simply due to wear on the plastic parts. If you can set it so that the "rest" postion is slightly different to what it was, it may just fix the problem.

P.S. Makes life a hell of alot easier!

[TomoHawk]

My 280Z has something like this. I think it's because if the stall speed of the torque converter being kind of high. I just start pushing down on the gas pedal at first with very little thrust, until the RPMs come up high enbough to get the torque converter to kick in. I had it sideways on the main street once! ( wet street- no traffic or police, fortunately) good thing I practice sideways in the winters, but that's in my Escort, which is FWD

thx

[sblake01]

TomoHawk, have you modified the torque converter? Every Datsun I've driven with an automatic, either Borg Warner or Nissanmatic would hook up at the first push of the throttle.

[Zedrally]

THere is a simple modification to this.

I'll try to write it up over the weekend.

MOM

[winstonsmith]

If you can set it so that the "rest" postion is slightly different to what it was, it may just fix the problem.

I think you have it right there! I have been messing with mine some more. My torsion rod was installed upside down and I put it on correctly however this didn't do anything for the problem. After removing all the accelerater linkage one piece at a time to figure out where the sticking was occuring I traced it to this part that I have circled in the picture. I'm a bit of a novice but this is the throttle body right? The part of the linkage that connects into this throttle part is where the sticking is happening. If there was some way to set the accelerater linkage's rest point to just a tad higher than where it normally sits then the sticking doesn't happen. I have noticed though that sometimes it sticks while driving, not just in it's rest position but when I'm driving and let off the gas the gas doesn't actually let up. For instance I come up to a stop light and put my foot on the brake and see that the rpms are still like 2000 or something and I have to tap the pedal to unstick the linkage again. Maybe the linkage piece on the throttle needs to be removed and cleaned up? What am I up against if I pull that piece off? I see two springs, the lever piece and a bolt holding it all in but is anything else inside there as well?

[winstonsmith]

Just bumping this topic back. I still haven't fixed this yet as it's been too cold to bother but it's warming up so I want to get this taken care of. As you see in the picture above the part that I have circled is what is sticking.That little lever piece gets stuck in the resting position and requires more than normal force to get it to move. When enough force is applied to make it unstick and start moving it really moves and the RPMs go soaring. Sometimes while driving when I let off the gas pedal that lever doesn't drop back into the rest position, it just stays where it was and I have to tap the gas pedal to unstick and make it drop back down. The springs on this lever are fine. The problem has to do with whatever it is this lever pivots on. If I spray a little WD40 on it before I start it up then it will work fine all day but the next day it's all sticky again. Anyway, I obviously need to take this lever off and clean up whatever it is it pivots on but I don't know what will happen if I take it off. I can see the two springs and how they come off and that the lever is held in place by a bolt. If I take the bolt off does the lever just come right off? What else is in there? I don't want a surprise when I take this off. I have a service manual for this car but it doesn't have anything in it about taking apart or cleaning this particular part. Are better pictures needed to show what I'm talking about? I want to get this fixed soon but I don't want to do something that ends up leaving the car in the driveway for an extended period of time. I'm going to be stripping stuff out of my Pulsar and fixing all the things that are wrong with it and I need the Z to be my daily driver.