Throttle stuck wide open?

[RJ911SC]

79 911 SC
first start in 4 years,
went to start my 3.0 yesterday, after building oil pressure, connected the fuel relay, coil etc. started up however throttle seems to be stuck wide open, never hit the gas pedal though, tried this 4-5 times same result each time, each time i shut it off immediately.
should note a couple of things, i had to be rebuild the throttle linkage from the transmission to the engine, and the gas pedal has movement, but only about half of what it should, it does have cruse control but never worked, cable is still in place i can pull the cable and the throttle linkage at engine will open,and release fine. Fuel line from the fuel filter to engine or fuel injection system burst, but that was due to incorrect fuel line replacement, replacing with high pressure line now, when looking at the linkage mounted on the engine where the cruse control and the throttle linkage meet,it seems fine, lots of correct movement, thought about dis connecting the linkage and try and start it without connected.
this was all the result of a CV joint failure i had a few years ago, where driving down the highway driver side let go, and tore out linkage at transmission, e brake cables, rear brake line,clutch cable i have replaced all e brake cables, all brake lines,new CV joints, clutch cable new linkage and bushings from the transmission to the engine, plus a lot of other needed replacements while i had it all apart.
So wondering about the high rev at start up, could it be an old vac line failure or not connected? anyone had this issue with wide open throttle at start up? i personally dont think its the linkage causing the problem, i will look at the pedal cluster again as i had to replace the clutch cable and might not of connected the gas pedal properly or it binding there. , i do kind of remember this, when i was driving and the CV joint came off, i remember that all the cables linkage hoses wrapped around the CV axle, and it revved quite high as i pulled over tho the side of the road and shut it down, but remember at the time restarting and it was fine at idle, except no throttle, due to the carnage from the CV failure,

[JohnJL]

I dont have a fix for you, but a laugh if you want to envision that same thing happening to me entering turn 7 at Eastern Creek! Brownshorts moment for sure.

[tdw28210]

Had this occur off and on for awhile. It was the throttle pedal bushing. Pissed off the neighbors and generally freaked me out. Occurred a few times while driving down the road too.

[RJ911SC]

checked the pedal bushings seem fine , anyone else , have anything to add?

[Joe Bob]

The cable could be binding, throttle on the engine may have some issues, cable housing may have a kink or is broken.....

[timmy2]

Pull the pope's hat off the throttle body and look inside to see where the TB plate is sitting.
Also check your fuel pump piston isn't stuck wide open.
Should move freely up and down with the movement of the air metering plate.

[chrismorse]

For all of you power brake guys, this is serious ****. I had it happen to me in my work truck, with the rear view blocked and the right side mirror also blocked - talk about a brown shorts moment!!!

Coincidently, I was on my way to my sister's memorial service when the incident occurred on the freeway - I couldn't see behind or on the right side and the ****ing brakes didn't work, The engine was WFO and I needed to take the next off ramp to her service, so I gritted my teeth, after turning on the turn signal and eased over to the right hopeing that it was clear.

I lucked out and fetched back the floor mat, got off at the right off ramp, went to her service and nailed the F***ing floor mat back down.

Power brakes are a B**ch when they don't work.

Happy Motoring,
chris

[bigel]

+1 Check the throttle body on top of the engine. The shaft of the throttle body on my '87 was significantly corroded and although mine wasn't binding, I could definitely see that happening.

Originally Posted by Joe Bob

The cable could be binding, throttle on the engine may have some issues, cable housing may have a kink or is broken.....

[rip78sc]

RJ911SC - did you ever find a fix for this? I'm having the exact same problem after an engine drop. 78 SC.

Any advice very much appreciated - I'm going to check the throttle body tonight, all linkage seems correct.

Thanks,
Rob