I bought the Viper green 914...have a problem with accelerator, Gas pedal pushes very jerky, not smooth, where to look first? Options

[Ampex351]

I was the lucky one who bought the Viper green '76 914. Great car. They put in a new accelerator cable before I got it. The pedal pushes real stiff and jerky not smooth at all. Takes most of the fun out of driving. What would you suggest looking at first?

Thanks, Roger

[rjames]

I was the lucky one who bought the Viper green '76 914. Great car. They put in a new accelerator cable before I got it. The pedal pushes real stiff and jerky not smooth at all. Takes most of the fun out of driving. What would you suggest looking at first?

Thanks, Roger

Nice! Would love to see more pictures of it.

I could be that the cable is binding somewhere in the tunnel or in the engine bay, or an issue with the throttle body butterfly mechanism itself. It could also the the pedal (they get rusty and crunchy where they attach).
I'd start with looking at the cable in the engine bay (easiest to do). Disconnect it at the throttle body and see if the butterfly moves easily enough. Then check the tunnel and make sure the cable has a free path to the pedal and isn't wrapped around anything. If the cable is fraying that could also cause it to fee stiff.

If those check out ok, disconnect the cable from the pedal and inspect the pedal itself.

[Badinfluence1]

I was the lucky one who bought the Viper green '76 914. Great car. They put in a new accelerator cable before I got it. The pedal pushes real stiff and jerky not smooth at all. Takes most of the fun out of driving. What would you suggest looking at first?

Thanks, Roger

A new throttle cable will go a long way to fix that- also look where the gas pedal connects to that ball plunger thing- that can hang it up as well.

[BillJ]

Terry cable throttle cable is nice.

[Craigers17]

Pretty much everything Rjames said. If you have to remove the pedal board, you might as well inspect the pedal cluster.....at that point you might as well replace the clutch cable as well. While you're looking at the pedal cluster, if it hasn't been serviced or replaced, you're gonna notice it's got a lot of surface rust, dirt, & grime around it. This will probably bother you, so you're gonna be tempted to pull the pedal cluster.

When you find that the pedal cluster is binding or sticky, you're gonna wanna rebuild it or, better yet, send your core to @bdstone914 and get a perfectly restored cluster in return. After realizing that you can't put his pristine new pedal cluster on top of that dirt & grime, you're gonna feel compelled to get out the wire wheel, primer, rust inhibitor, etc., and clean that area under the pedal cluster up.

At that point, you're gonna notice the nose of the brake master cylinder staring at you longingly, and you're going to think to yourself,.....Hell, I've got this whole damn thing pulled apart, I might as well replace the master cylinder. While getting under the car, and pulling off the MC, you're gonna ponder about putting in a new MC without putting in new brake lines....both hard and soft.....and as your eyes slowly follow those lines to the brakes, it suddenly hits you......these brakes look like shit...and maybe that scrubbing I'm hearing on the passenger side and slight wheel wobble is actually the brake pad that is permanently rubbing against the disc because the caliper has seized up.

Well....now you're into the brakes, so you might as well pull them off and send them off to PMB for a complete restoration....be sure to get new pads and possibly the plastic lines that run to the reservoir....to access them you might have to pull the fuel tank, or at least pull it out partially on the driver's side. You'll be glad you did this because when you figure out what a bitch it is to fit the new master cylinder with new grommets back on to the steel lines, you'll probably find it easier to do it on a bench, and then slide the lines back up from the bottom.

Since you pulled the tank partially, it will be a good time to check it out for pin hole leaks and replace the gaskets and fuel sock at a bare minimum. If you end up pulling it completely, in order to replace or refurbish it....or maybe just paint it, then it would be a good time to replace the fuel lines running through the tunnel.....unless they've already been replaced. It would probably be a good time to replace the lines under the tank as well......

Anyhow,....I digress.....in order to check whether the accelerator cable is binding with the clutch cable, pull the inspection cover at the front of the tunnel and take a picture inside the tunnel. You should be able to tell whether they are interfering with one another..... Here is a pic of the tunnel:(sorry the pic is sideways)



By the way....welcome and good luck....Don't pay any attention to my ramblings. I loves me some Viper Green!

[Root_Werks]

If the cable was stiff before and a replacement is still stiff, probably in the pedal cluster as others have said. You can try some penetrating oil on the cluster pivot point.

Can also disconnect the cable at both ends. Does it move freely? Does the little arm at the pedal cluster move freely? Does the throttle body arm move freely?

Quick and easy checks to discover the culprit.

Very nice score! I remember that 914 locally, it's very nice.

[bdstone914]

I was the lucky one who bought the Viper green '76 914. Great car. They put in a new accelerator cable before I got it. The pedal pushes real stiff and jerky not smooth at all. Takes most of the fun out of driving. What would you suggest looking at first?

Thanks, Roger

First do what others have suggested to see if it is a cable or ledal issue.
I have heard other complaibts that Terry cables use larger wire strands that can cause rough operation.
If that is the problem get Gemo cable to replace it.
Do inspect the bushings on the accelerator crank on the pedal set for side to side movement.
If your pedal set needs work i can restore it.

@Ampex351

[davep]

Does simply pushing on the clutch pedal affect engine speed any? A common problem was wrapping the two cables around each other causing binding. An inexperienced tech could have caused that when installing the new cable.

[rmk83]

Having this happen to my new to me '76 914. Makes it a little tricky to drive. LOL. Gave my girlfriend whiplash on our first drive the other evening. Not good. I pulled the carpet back today and hit the accelerator friction points with WD40. Not any better. Seems ok at the carb also. Will access the tunnel tmrw and see if I can see anything off then take pedal board off to check it out. Thanks for the tips here guys.

[rjames]

Nothing on a 914 needs WD40. (IMG:style_emoticons/default/smile.gif)

[Dave_Darling]

There are three basic parts to the throttle linkage on a 914.

The pedal (and bellcrank), the cable, and the throttle valve.

Pull the pedal forward and pop the ball-and-socket joint loose. Does the pedal move smoothly without being connected to the cable? If not, the pedal should be replaced--there is a hinge inside which can rust and get nasty.

Loosen the bolt that holds the throttle cable onto the throttle valve in the engine bay. Does the throttle valve open and close smoothly? If not, then you've got a problem in the valve.

Then push and pull the cable. Does it move smoothly? If not, it probably needs to be replaced.

Isolate and test. Throwing parts at the car is a good way to spend money without necessarily fixing the actual problem.

--DD

[Mikey914]

Could also be as simple as the pedal. There is a hinge internally on the bottom that does fail.
The pedal cluster is probably the least likely, but could be the issue. Then there is the clutch tube. This is a good project to start. Easy enough to get to the pedal. Hopefully it's simple. Lastly, if there is rust on the two bolts try penetrating oil overnight.
-Mark

[JamesM]

Could also be as simple as the pedal. There is a hinge internally on the bottom that does fail.
The pedal cluster is probably the least likely, but could be the issue. Then there is the clutch tube. This is a good project to start. Easy enough to get to the pedal. Hopefully it's simple. Lastly, if there is rust on the two bolts try penetrating oil overnight.
-Mark

(IMG:style_emoticons/default/agree.gif) that

Its a thing you don't expect but I have found that is usually what it is, or at least a contributing factor.

Gas pedal itself
Throttle cable
pedal bushings

Given how annoying a sticky throttle is, if you dont know they history just replace all of it.

Also i often find that the throttle cable tube near the firewall is bent. You will figure this out really quick when you cant get the head of the new cable through it. This can be another friction point.