throttle surge

baltor · Post by **baltor** » Sat Jul 10, 2010 8:54 pm

I just picked up a 712m, and aside from some electrical and other minor issues I'm fairly happy with it. Its quite fun to drive. One thing I noticed is when first accelerating and releasing the clutch (especially in the crawl speed or 1st), the engine will rev up by itself. It seems that if the engine continues to encounter load, it will continue accelerating which makes climbing a hill or trying to slowly navigate uneven terrain very interesting. I thought only toyotas had this problem.

My thought is maybe as the engine flexes in the mounts, its somehow applying gas via the hand throttle linkage? I havent really gotten into it yet, but will tomorrow. Any ideas would be appreciated.

edit: installed the new motor mount today. Feels like a cadillac now compared with how its been for the past 2 weeks. In short, it seems a solid (welded) mount is fine as a temporary repair, but as others have stated the rubber is there for a reason, and cuts down HUGE on vibrations felt/transmitted to chassis.

Twin Pinzies · Post by **Twin Pinzies** » Sun Jul 11, 2010 9:24 am

Pinzgauers don't flex much... at all. It must be your throttle linkage. Check the hand throttle too.

baltor · Post by **baltor** » Sun Jul 11, 2010 12:23 pm

found the problem - broken drivers side motor mount. Engine is moving too much when clutch engages thus causing the throttle linkage to "move".

dang - i'm set to go on a trip here in the next few hours. Guess I"ll have to come up with a creative temporary fix. Any ideas?

update: i need to get out of here shortly, so I'm going to weld it into a solid mount and order a new one this week. Anybody run anything besides stock mounts? Poly etc?

undysworld · Post by **undysworld** » Sun Jul 11, 2010 1:43 pm

I'd be leery of welding it into a fixed mount. I'd think it's there for a reason. IIRC, old chevy motor mounts were just rubber donuts, more or less. Perhaps some generic rubber parts could be kluged in there?

I've never heard of any mounts other than stock.

Best of luck.

Paul

Pinzgauer Pete · Post by **Pinzgauer Pete** » Sun Jul 11, 2010 3:19 pm

I know what I would do....not saying to do this... however if I were in your situation I am making a aluminum block and sandwiching it with rubber on both sides and bolting it in...of course I would order the proper mount and install ASAP.

baltor · Post by **baltor** » Sun Jul 11, 2010 4:01 pm

thanks for the suggestions - unfortunately time being of the essense, i welded in 2 strips holding the mount in place.

I did a quick check on the net, and apparently many people in the drag racing/sports car world use solid mounts, and claim the primary down side is engine vibration transmitted to the chassis. They are definately right! It vibrates quite a bit at idle, but smoothes out above 1k rpm. Hopefully it'll hold up for the week I'm away.

will make a follow up post when i return

Pinzgauer Pete · Post by **Pinzgauer Pete** » Sun Jul 11, 2010 4:47 pm

yup in drag race situations most do run solid...in your case however the mount is more critical when you are doing off roading stressing the mount far differently than a flat run. Just be sure to take additional materials and the proper tools to fabricate some additional part should a field repair become necessary....tear it up dude!!!