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> Help! My 914 1.8 is revving high!, help with mechanical problem
Brandi
post Mar 26 2010, 11:06 PM
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Hello all --

I have a 1975 1.8 that seems to have either a stuck throttle cable, or stuck float.

here's the issue:

When I start the car it promptly shoots to 5500 RPMs -- it's revving high. The gas pedal moves smoothly, and the cable in the engine compartment doesn't seem to be stuck.

I've tried adjusting the idle screw, but it doesn't have any affect one way or the other.

Can anyone help with this -- what can I do? I'm getting desperate. The weather's good, and I want to drive my baby!

Thanks for any advice.
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Kirmizi
post Mar 27 2010, 12:49 AM
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Carburetors? One or two?
I'd start by checking the linkage(s) to see if anything's binding.
Then check the butterflies to make sure they're closing properly.
Mike
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RJMII
post Mar 27 2010, 03:24 PM
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(IMG:style_emoticons/default/welcome.png)

Mike's got some good advice there. =o)

pull the air filter(s) and look at the butterflies.
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PeeGreen 914
post Mar 27 2010, 03:34 PM
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Are you sure the throttle cable isn't wrapped around the clutch at the pedal cluster? I have seen the cable drop down and wrap itself around the area where the clutch cable attaches causing something like what you are saying.
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TheCabinetmaker
post Mar 27 2010, 03:40 PM
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Undo the cable from the linkage. That will eliminate one of the two.
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Brandi
post Mar 27 2010, 05:42 PM
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Thanks guys --

I pulled the air filter, and everything seems to be moving okay.

Although I've had my 914 for 10 years, and I've done a lot of work on it myself, this is a new one for me.

When I pulled the AF off, there wasn't any butterfly under it (unlike say, a buick).

The accelerator pedal is moving freely -- doesn't stick.

What else can I check?
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Brandi
post Mar 27 2010, 05:43 PM
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QUOTE(vsg914 @ Mar 27 2010, 02:40 PM) *

Undo the cable from the linkage. That will eliminate one of the two.


Thanks -- how do I do this?
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BMXerror
post Mar 27 2010, 05:51 PM
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QUOTE(Brandi @ Mar 26 2010, 10:06 PM) *

Help! My 914 1.8 is revving high!

SHIFT!



Sorry.... Couldn't help myself. (IMG:style_emoticons/default/biggrin.gif) BTW
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Mark D.
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Brandi
post Mar 27 2010, 05:55 PM
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QUOTE(BMXerror @ Mar 27 2010, 04:51 PM) *

QUOTE(Brandi @ Mar 26 2010, 10:06 PM) *

Help! My 914 1.8 is revving high!

SHIFT!



Sorry.... Couldn't help myself. (IMG:style_emoticons/default/biggrin.gif) BTW
(IMG:style_emoticons/default/welcome.png)
Mark D.


Is THAT what that stick thingie is for????

Thanks for the laugh -- I needed that.
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PeeGreen 914
post Mar 27 2010, 06:06 PM
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The gas pedal will still move freely if it is looped at the pedal cluster. Remove the pedal board and look at where the accel and clutch cables connect to the cluster. Should only take five minutes and then you can cross it off you list of possible causes.
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Kirmizi
post Mar 27 2010, 06:12 PM
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Here's a pic of a single carb butterflies and another where the throttle cable connects. Mike


Attached image(s)
Attached Image Attached Image
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Tom
post Mar 27 2010, 06:13 PM
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Fuel injection or carbs? You said you took the AF ( singular) off and didn't see a butterfly. Carbs would have two air cleaners. If fuel inj., I think air leaks cause high RPMs.
Tom
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Brandi
post Mar 27 2010, 06:39 PM
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QUOTE(Tom @ Mar 27 2010, 05:13 PM) *

Fuel injection or carbs? You said you took the AF ( singular) off and didn't see a butterfly. Carbs would have two air cleaners. If fuel inj., I think air leaks cause high RPMs.
Tom


Okay, I feel pretty dumb, but... I'm pretty sure I have fuel inj.

In my defense, the car was parked for 2 years before going into the shop. Two years is long enough to forget most of what I once knew!!

It came out of the shop, ran fine, no problems. It sat for 2 months, and when I fired it up, the gas pedal stuck, then came free and now it's idling high.

I'm going to try to pull the pedal board tomorrow and see if that's the problem.
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Rick L
post Mar 27 2010, 07:42 PM
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QUOTE(Brandi @ Mar 27 2010, 08:39 PM) *

QUOTE(Tom @ Mar 27 2010, 05:13 PM) *

Fuel injection or carbs? You said you took the AF ( singular) off and didn't see a butterfly. Carbs would have two air cleaners. If fuel inj., I think air leaks cause high RPMs.
Tom


Okay, I feel pretty dumb, but... I'm pretty sure I have fuel inj.

In my defense, the car was parked for 2 years before going into the shop. Two years is long enough to forget most of what I once knew!!

It came out of the shop, ran fine, no problems. It sat for 2 months, and when I fired it up, the gas pedal stuck, then came free and now it's idling high.

I'm going to try to pull the pedal board tomorrow and see if that's the problem.


The L-Jet (1.8 specific) has a cold start injector that is vaccuum operated.
It is located under the fuel plenum towards the front of the motor (look between the dizzy and the plenum) find the injector and unplug it. If this fixes the problem the issue is most likely either a ground fault or a bad diaphragm.

I'll see if I can find you a pic.

Good luck,
Rick
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Kirmizi
post Mar 27 2010, 07:48 PM
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Oooooooooh, that changes everything! (IMG:style_emoticons/default/biggrin.gif)
Mike
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Brandi
post Mar 27 2010, 07:52 PM
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QUOTE(Kirmizi @ Mar 27 2010, 06:48 PM) *

Oooooooooh, that changes everything! (IMG:style_emoticons/default/biggrin.gif)
Mike


Mike -- how does this change everything?? (IMG:style_emoticons/default/sad.gif) Should I not bother with taking the pedal board off?

And thanks for all the advice -- I appreciate it! Bloody car is a pain in the a$$, but I just love it, anyway!
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Kirmizi
post Mar 27 2010, 07:59 PM
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The throttle cable's the same, check both ends: under the pedal board and where it connects to the throttle body. I'd also make sure the ground strap between the transmission and body is present and in good shape. If it's missing or bad, your throttle cable becomes the ground and it melts into the sheath...
Don't ask me how I know.
Mike
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Tom
post Mar 27 2010, 08:29 PM
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I think what Mike was refering to was ( is it carbs or FI). Depending on what you have, some of the troubleshooting will be totally different.
Have some one see if the throttle assy. on the engine follows the pedal movement. If so, then the problem is not your pedal or cable. Instead, since you have fuel injection, you probably need to check out things on the FI that can cause high RPMs. 1.8's = L-jet? And if I remember correctly, vacuum leaks on L-jet can cause high RPMs.
Tom
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PeeGreen 914
post Mar 28 2010, 11:59 AM
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(IMG:style_emoticons/default/confused24.gif) Did you look at the pedal cluster yet?
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