sticky throttle - PeachParts Mercedes-Benz Forum

b52rule · #1 02-21-2007, 04:40 PM

I've been thru the search and threads and lubed all the connections I could find.

In cold weather, first start in the morning the throttle will be very slow to return to it's idle of 550 rpm. I can accelerate but when backing off the throttle the car will drop speed, but not much. After the engine warms up the throttle behaves normally. I've lubed every ball joint I can find up to the IP and fwd of the throttle pedal that I can find.. I can pull back the throttle linkage on the engine while it is running in the driveway and there is some resistance, that goes away as the engine come up to temp. This resistance appears aft of the IP.

Did I overlook a piece of linkage perhaps aft of the IP and fwd of the firewall?

PanzerSD · #2 02-22-2007, 02:38 AM

I dealt with the same issue just yesterday...would idle high and slow downs were kind of scary...I had Ice build up ad the bottom of my pedal, and when it would warm up the floor heat would melt the ice and it'd feeeze and my pedal would be stuck a little....

Edit: Just noticed you're from SoCal....

the back of the pedal might need some lube too..

dannym · #3 02-22-2007, 07:57 AM

There's a throttle bushing on the firewall that may need to be replaced.

b52rule · #4 02-22-2007, 03:47 PM

We don't get much ice in San Diego but the linkage was "stiff", only in cold weather, about 20 degF. I'll look for that bushing on the firewall although I did not see it when I removed some plastic pieces near the firewall, interior side.

It seems I may have to drop the floorpan to find that busging.

I will post results.

b52rule · #5 02-22-2007, 03:47 PM

We don't get much ice in San Diego but the linkage was "stiff", only in cold weather, about 20 degF. I'll look for that bushing on the firewall although I did not see it when I removed some plastic pieces near the firewall, interior side.

It seems I may have to drop the floorpan to find that bushing.

I will post results.

Diesel Giant · #6 02-22-2007, 04:26 PM

The bushing or the spring on the bottom of the IP pump. You may have a bur or broken internal spring in one of the ball sockets.

FineOlBenz · #7 02-22-2007, 10:16 PM

If you have been doing some adjustments to your idle or throttle pressure (bowden cable) you may have upset the balance of the linkage for the EGR vacuum controls. Remove the black cover on top of the valve cover and you will see how it can bind on throttle release.

b52rule · #8 02-22-2007, 10:56 PM

I have not made any adjustments and the binding appears aft of the IP. I'll look at the cable. I goes away as the engine warms up.

Bruce Kennedy · #9 02-22-2007, 11:37 PM

I had the same problem on my td. The cause of the problem was one of the plastic bushings on top of the rocker cover had some grit in it keeping the linkage from moving freely. I think the po must have greased it and that is a mistake. Took a while to figure this one out, I ended up removing all the linkage ,and the pedal till I found the culprit.