biosurfer1

I tried to fix my cruise control tonight by cleaning the servo like suggested at Clarke's. Before I cleaned the servo, it would engage rarely and if it did, it would accelerate until I put my foot on the break. I could push the lever forward and the car would accelerate but if I let go, most of the time the cruise control would not engage.

So after cleaning the servo, hardly anything has changed. I made sure the servo arm worked, cleaned the tracks with contact cleaner and greased the gears....didn't really help. The only change is the cruise control seems to engage more, but still doesnt always and still has the acceleration problem. When I would push the lever forward and let go, I would hear a "clunk" coming from the drivers footwell. I know the cruise control computer is located there, but what could cause the clunk? I will try to clean the computer tomorrow, but does anyone know what the clunk could be or what to look for?


Next question is is about acceleration at higher speeds for you N/A guys. I was seeing what my 944 could do down a deserted road and I was a bit disappointed in the higher end performance. Getting up to 80mph was no prob, but once I hit 5th gear its real slow going from 80-100 and up...is this normal? I guess I'm looking at the second half of the speedo thinking to myself thats a lot of real estate to cover that would take a LONG road to get through...just seeing if this is normal?

Thanks guys!

MM951

Can't help you on the cruise control (never had it on a 944) but I can tell you 5th gear really sucks in an n/a until over 4K (there is a terrible deadspot between 4th and 5th) but then it will pick up a bit better. At least thats what I experienced in my 84 and 85 N/As as well as my mothers 86 N/A

biosurfer1

thanks for the info...thinking about it, I dont think I ever got over 4k, will have to try tonight. Any idea of the throttle response cam helps with that at all?

Scootin159

The throttle response cam adds 0hp and 0ft-lbs of torque. It essentially just modifies the gas pedal so you don't have to push it down as far - wearing thicker soled shoes would do nearly the same effect.

biosurfer1

Thanks....I knew it didn't add any performance. I was just wondering if it might be the cause for the dead spot in the RPM range.

My understanding is the original throttle cam was like an archery bow in that at first, its tougher to pull back but once you "pull back" far enough, it gets much easier. The throttle response cam makes it more linear throughout, correct?

smlporsche

Run the car up to 6K before shifting it will help mitigate the gearing.
And of course do this on a track not a public road....

Scootin159

Essentially true, but the opposite. The 'stock' throttle cam ratio is such that you need more pedal movement at first (which is 'easier' - not that it really requires much foot strength anyways), but then 'stiffens up' as you reach the end of it's movement to become more linear. The aftermarket cams just make the movement linear throughout it's whole range of movement.

Calmchaos

Am I the only one that liked the stock cam?

biosurfer1

I don't mind the stock cam. I'm not going to spend money to change it, but it would be fun to see the difference between the two.

biosurfer1

any thoughts on the clunking noise from the drivers footwell?

Calmchaos

About the cruise accelerating on its own, it is the computer. I had the same problem until I replaced mine with a good used one.

For the clunking noise I had a abnormal cause.
I removed the AC and the big connector for the dryer was tapping against the wheel well, even though I thought I tied it down well.
99% probably not your problem. LOL. Just thought I would share.

Mike C.

As for top speed, I found it best to just red line 4th gear and then shift to 5th. Those last 10 - 15 mph do take a while (I saw an indicated 130 - this was before GPS's). As for the CC, I have a few posts on this subject out there. It certainly could be the brain but the final fix for mine was fixing the poor ground (I had alrady re-soldered the brain which didn't fix the problem, nor did cleaning the servo).

StoogeMoe

What you're probably hearing is the CC releasing the throttle. It should be more of a thump than a clunk. I would check your CC stalk. It sounds like the switch is bad which is telling the CC to continually accelerate. Maybe clean the contacts and see if that helps. Might explain the flaky engagement also.

mtccl

I had to replace the CC computer under the dash to get my erratic CC to work properly. Works like a champ now, but that small box is a major PITA to get to. Driver's side up in the corner above the clutch..silver box the size of 2 cigarette packs.

biosurfer1

Thanks guys...I'll pull it out tomorrow night and see if I can clean it up. I just want to have as much as possible working when I sell the car.