Clutch in to shift and car revs up?! Also throttle holds.

[jmile46]

Hello everyone, the new to me e34 is having an odd issue.
So when I push in the clutch to shift, the car revs itself. If Im driving hard, like 1/2 to full throttle it revs itself more. If its easy driving it holds revs. When Im cruising if I release throttle it will also hold revs and then eventually stops. The gas pedal itself feels sh*tty for a lack of better words. It feels sticky. Im thinking the pedal is sticking because If I reach down and pull it up it stops revving.

Things to note, this car started life as an automatic. So the gas pedal itself is an auto pedal.

So what can I look at for causing the issue? Would this issue be the pedal itself or the throttle cable? Can I put a manual pedal in? Thanks guys!

[moroza]

Auto pedals are the same as manuals. It could be a sticking throttle cable, throttle itself, and/or the pedal bushings.

[jmile46]

Auto pedals are the same as manuals. It could be a sticking throttle cable, throttle itself, and/or the pedal bushings.

I thought they were different? Because auto pedals have the button past full throttle that makes them downshift again no? Because I can feel the button on this.

[ross1]

Check for an unraveling cable at the throttle body, dislodged bushing where the cable attaches to the bracket and also there is a plastic bushing on the pedal fulcrum that wears out.

[tantumaude]

My manual 540 does that too, but only for 1/4 of a second or so. I'm told it has something to do with the Dinan software. In your case though, given that you have time to reach down and pull the pedal, I'd agree with moroza--something's sticking. Knowing the year and engine would help.

[eddycooper]

Also check for a floor mat pushed up on to the bottom of the gas pedal. My heavy rubber mats don't stay in place and they rest on the gas pedal sometimes.

[ross1]

I see the car is swapped from an automatic.
Your issue could also be with the DME if it the original one. Apparently, from what I've read here, an auto car's DMEs are intended to have the throttle come down slowly, not sure why, never thought about it.

[jmile46]

My manual 540 does that too, but only for 1/4 of a second or so. I'm told it has something to do with the Dinan software. In your case though, given that you have time to reach down and pull the pedal, I'd agree with moroza--something's sticking. Knowing the year and engine would help.

Whoops I forgot to mention. Its a 92 m50 but no software that I know of.

[jmile46]

Also check for a floor mat pushed up on to the bottom of the gas pedal. My heavy rubber mats don't stay in place and they rest on the gas pedal sometimes.

Floor mat is not an issue. Ive checked lol.


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[jmile46]

I see the car is swapped from an automatic.
Your issue could also be with the DME if it the original one. Apparently, from what I've read here, an auto car's DMEs are intended to have the throttle come down slowly, not sure why, never thought about it.

I will check everything you stated. Thanks! But my buddy also mentioned it could be auto dme but Im not sure that would make the car rev itself so crazy. Holding revs I could understand. Not revving to 6k. I will investigate the pedal tonight. The pedal itself feels sticky. When I first bought car it did not do this. And that was about 3 weeks ago though.

[Mihnea"e34]

My M50B20 has the same pedal issue. If i pull the pedal or press on the throttle body with my hand it settles at normal rpm. It drives me crazy

[jmile46]

My M50B20 has the same pedal issue. If i pull the pedal or press on the throttle body with my hand it settles at normal rpm. It drives me crazy

Have you done anything to investigate the issue? Being almost 30 years old something is bound to be weak.

[BleedsBlue]

I wouldn't even spend time researching this more until you check the hardware, honestly.

My car (not an M50, but still) also did this when it had a tear in the intake boot, aka, a massive vacuum leak. Somehow it was idling pretty normally but when I clutched in, revs would raise. My money is more on a sticky throttle cable component in your case, though.

[moroza]

Yes, manual-swapped 540i seem prone to some RPM hanging. However they idle fine. Software is (probably) not your problem.

There is a separate kickdown button on automatic cars, but it's not part of the pedal assembly.

[jmile46]

Yes, manual-swapped 540i seem prone to some RPM hanging. However they idle fine. Software is (probably) not your problem.

There is a separate kickdown button on automatic cars, but it's not part of the pedal assembly.

Ah yes I see that now. Can I remove that button?

[jmile46]

IMG_7723.JPG
IMG_7725.JPG

Its hard to tell through pictures but the first picture is the throttle completely upright. (No throttle) and the second one is what it looks like when it returns after me releasing throttle. Its hard to notice but the throttle isn’t all the way back. It has a slight bend in the top flap that connects to metal rod. So something is stopping it from returning. Any guesses what? Could I just need to grease that rod that goes through loop?


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[moroza]

You can remove the kickdown switch, but it doubles as a pedal stop, so I'd keep it until you have a replacement manual pedal stop.

Sorry, but those pics don't show me anything. The gas pedal shaft has bushings that I bet are all chewed up. I recommend disconnecting the throttle cable at both of its ends, and moving by hand: 1. the pedal and shaft, 2. the cable, and 3. the throttle plate. One or more of those are not going to move smoothly or return properly.

[K Fox]

If you look for the threads I've started, I have one on cleaning and lubing the throttle bar assembly. That will help you out immensely, I would imagine. On the topic of it hanging rev's, that really seems to be in the programming of the engine - I saw you said your's is an M50 car, but I'd be surprised if they were any different from the M60 cars (which are known for hanging rev's on manual swaps). Thankfully, there are a lot of options for chips for an M50 that give you options - you just need a chip for a manual car. I give that a 90% as being that issue, and breaking out that throttle assembly and giving it a once over will be a huge improvement - it really strikes me as a kinda of weak point in these cars. It adds a layer in between the pedal and the throttle - but when it's right it's OK. Your's in likely no better than mine was in my pics.

K Fox

*edit* Decided to link the relevant thread for convenience: The learning is in here...

[jmile46]

You can remove the kickdown switch, but it doubles as a pedal stop, so I'd keep it until you have a replacement manual pedal stop.

Sorry, but those pics don't show me anything. The gas pedal shaft has bushings that I bet are all chewed up. I recommend disconnecting the throttle cable at both of its ends, and moving by hand: 1. the pedal and shaft, 2. the cable, and 3. the throttle plate. One or more of those are not going to move smoothly or return properly.

Gotcha. Yeah pics are useless. Will do though!


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[jmile46]

If you look for the threads I've started, I have one on cleaning and lubing the throttle bar assembly. That will help you out immensely, I would imagine. On the topic of it hanging rev's, that really seems to be in the programming of the engine - I saw you said your's is an M50 car, but I'd be surprised if they were any different from the M60 cars (which are known for hanging rev's on manual swaps). Thankfully, there are a lot of options for chips for an M50 that give you options - you just need a chip for a manual car. I give that a 90% as being that issue, and breaking out that throttle assembly and giving it a once over will be a huge improvement - it really strikes me as a kinda of weak point in these cars. It adds a layer in between the pedal and the throttle - but when it's right it's OK. Your's in likely no better than mine was in my pics.

K Fox

*edit* Decided to link the relevant thread for convenience: The learning is in here...

Thank you so much!! I read through the diy and will address everything stated. I may even look into a a tune also!

[m735is]

My 95 did this during the cold weather sometimes. I lubed up the throttle linkages, which seemed to help for the most part. As an extra precaution, I put in a new throttle cable and pedal bushings (mine were almost completely missing). Haven't had the issue since- a year or two. Mine was already a manual so it wasn't a software issue.

[jmile46]

My 95 did this during the cold weather sometimes. I lubed up the throttle linkages, which seemed to help for the most part. As an extra precaution, I put in a new throttle cable and pedal bushings (mine were almost completely missing). Haven't had the issue since- a year or two. Mine was already a manual so it wasn't a software issue.

Definitely going to do those. Waiting to have time to do it currently.

[prettyfoot]

I manual swapped my touring a couple months ago and still have all the auto software. I don't have any problems with hanging throttle so I don't know if software is your problem.

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[jmile46]

I manual swapped my touring a couple months ago and still have all the auto software. I don't have any problems with hanging throttle so I don't know if software is your problem.

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Thats good to know. Thanks for the input!

[jmile46]

Welp it is with great embarrassment that I have found the issue to my problem, and like eddycooper stated it was the damned floor mat resting on the very edge of the gas pedal. Oem floor mat! Not heavy rubber either. The pedal still totally needs an overall because it is sticky and weak, but now that the floor mat is out no more issue! Thanks to everyone who helped. I will take all your advice to refurb my gas pedal soon!


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