no throtle response 1998 E300 TD - PeachParts Mercedes-Benz Forum

nohuti · #1 03-09-2014, 04:32 PM

Greetings, I have a 1998 E300 TD that has been stored for 6 years. I put a new battery in and started it but it does not respond to throtle input. I checked with the dealer and the first part after the cable is $750.

Does anyone have an idea?

barry12345 · #2 03-09-2014, 07:57 PM

Linkage to the injection pump stuck sitting so long? Easy fix just verify by pressing the pedal or having someone else do it while the lever on the injection pump is watched.

This is not a drive by wire or electrical throttle is it? Even then the mechanical portions of the set up may be stuck or the control at the pedal end oxidized. I would not take this issue to a dealer unless you have deep pockets from what you have quoted.

I have stood in lines at service places for this brand at dealers. What I have heard being paid for biils was ridiculous.

nohuti · #3 03-11-2014, 09:55 AM

Thankyou for the fast response. It is a by wire but the fix could work. That is under the intake manafold of course! I will pick up a gasket and have a look. There is also the BAS and engine elictronics and check engine lights but I can pull the codes and see what that is.

pawoSD · #4 03-11-2014, 09:58 AM

The part you quoted at $750 from the dealer can be had for under $300 online....if its the same throttle position sensor as the gas cars use....

barry12345 · #5 03-11-2014, 12:34 PM

Quote:

Originally Posted by pawoSD

The part you quoted at $750 from the dealer can be had for under $300 online....if its the same throttle position sensor as the gas cars use....

If you eventually need that expensive part. Plus the gas cars are similar the auto wrecker circuit may be a possibility. At some point the electrical signal is changed into a mechanical one I suspect. . This part may just be stuck from sitting. Oxidation if they use a potetiomenter or variable resistor at the pedal end would be another suspicion.

Since you have an ohmmeter just checking after unplugging between the two components should at least indicate at which end of the throttle system the issue lies. Clean all the contacts on the respective plug or plugs. If it also feeds the computer and I suspect it may be cautious about shorting anything while checking. Although I have never yet had occasion to work on one so some of it is guesswork.

I think we have one throttle by wire car that is non Mercedes. One has to ask themselves where is the advantage over a simple mechanical linkage? Electric steering booster as well yet the car does not give particularily spectacular milage.

I no longer know what if anything justifies fairly simple parts having the list prices they have. Some cars are actually off the road because people can not or will not pay the price of them.

TMAllison · #6 03-11-2014, 01:20 PM

The potentiometer is next to the fuse box on the drivers side firewall, throttle cable from pedal attaches to it. You can manually manipulate it. If its moving and idle doesn't increase its probably bad. Step two would be checking the opposite end of the harness at the IP to see if its loose, etc.

After 6 years, I would expect you'd have a bunch of dried out o-rings on fuel lines and the SOV, etc. that will need replacing.

KarTek · #7 03-11-2014, 02:45 PM

Just a thought, try switching off the ASR (switch on the upper left of the shift console) this should display an orange triangle in the middle of the speedometer.

Then, try the throttle. If it works, you might actually have a problem with the brake switch or some related part. The programming makes the car not respond to throttle input if the brake is applied.

Also, try running the gear selector through the gears (engine off) about 10 or 20 times in succession. There may be something goofed up in the console having an effect on the throttle.

Lastly, if you have access to a scan gauge, you can set it to display TPS. If you note TPS is going up and down properly when you press the accelerator, the sensor is likely not at fault.