93 300E throttle issue - PeachParts Mercedes-Benz Forum

jake12tech · #1 01-14-2019, 11:16 PM

Out of my realm here with this car. Just trying to fix it up enough so it’s drivable so I can resell it for what I got into it. The biggest issue at the moment is that after driving the car maybe 20 minutes the pedal develops a ton of slack in it and you have to put the pedal to the floor almost and it revs up to 4 grand and quits shifting. Stays in 1st gear. I’m so confused. The Bowden cable seems fine, I tried adjusting the throttle by turning the knob around a few times which did nothing. Any ideas? Bad throttle cable? Just develops a massive ton of free play in it.

This is on the priority list besides the complete lack of brake pedal as well.

jake12tech · #2 01-15-2019, 07:04 PM

47 views and no one can give me an idea.

Rrrockhound · #3 01-15-2019, 08:38 PM

Does the pedal return on its own when this is happening? Are you actually seeing slack in the cable or does it just feel that way to your right foot? Checked your trans fluid level?

jake12tech · #4 01-15-2019, 09:45 PM

Quote:

Originally Posted by Rrrockhound

Does the pedal return on its own when this is happening? Are you actually seeing slack in the cable or does it just feel that way to your right foot? Checked your trans fluid level?

Yeah I checked the trans fluid. The pedal returns on its own. Adjusting the screw clockwise or counter clockwise does nothing. If you have someone press the gas and watch the linkage it literally does nothing until the pedal is almost to the floor. And you can feel the free play in pedal from inside the car.

Stretch · #5 01-15-2019, 10:21 PM

Probably not this but I'll mention it - I've had trouble with floor mats getting in the way of the accelerator pedals before. (It sure makes you feel a bit daft when you discover that!)

At the other end of the throttle there will be a spring and a rotating shaft. Make sure that is well oiled. Disconnect the cable and see how that feels. Mechanical connections running from the throttle assembly need to be considered such as say cruise control if that's the case.

Is this still CIS? Around 1993 things started to get more modern with EFI and wasted spark etc...

ccrelan · #6 01-15-2019, 10:36 PM

Does your throttle body have replacement wiring? The throttle bodies have the same crap bio wiring as engine harnesses on m104 cars. There should be a date code on the throttle body that may or may not be legible at this point.

sixto · #7 01-15-2019, 10:38 PM

A ‘93 300E probably has electronic throttle. What you describe sounds more like limp mode than slack.

Has the harness been replaced? ‘93 is smack dab in the engine harness problem years.

Hook it up to SDS if available to you or look up building a blinking LED code reader.

Sixto
98 E320s sedan and wagon
02 C320 wagon

Zulfiqar · #8 01-16-2019, 11:12 AM

93 should be a 300E 2.8 (M104)

the throttle is going into failsafe, check the wiring for shorts. The wiring can also fail inside the throttle assembly.

jake12tech · #9 01-16-2019, 12:46 PM

Quote:

Originally Posted by Zulfiqar

93 should be a 300E 2.8 (M104)

the throttle is going into failsafe, check the wiring for shorts. The wiring can also fail inside the throttle assembly.

It’s a 3.2. Does it make a difference?

How expensive is a harness?
Thanks everyone for the responses.

Zulfiqar · #10 01-16-2019, 02:49 PM

Quote:

Originally Posted by jake12tech

It’s a 3.2. Does it make a difference?

How expensive is a harness?
Thanks everyone for the responses.

wow - you have sort of a unicorn.

the difference in the harness and throttle is if the car is ASR equipped or not, The harness can be rebuilt as its just a bunch of wires. The wires internal to the throttle are not easily repairable and best find a rebuilt throttle - I think you can also find a rebuilt harness for your car too.

jake12tech · #11 01-16-2019, 03:58 PM

It has ASR. I’d likely rebuild it. Cheaper than buying a rebuilt I’d imagine. Plus I think I plan to keep the car now since I’ve had zero luck even getting $500 for it. Scrapping it is not an option considering I’d get $150 at a metal yard

ccrelan · #12 01-16-2019, 05:02 PM

You can easily check the date code on both the wiring harness and the throttle body. If they are originals, replace them.

Second hand rebuilt examples of both are all over ebay. The wiring harness tag is over by the battery area. Info on the bio wiring is very easy to search and find all over forums and youtube.

sixto · #13 01-16-2019, 10:28 PM

The ‘93 300E was available with 2.8 M104 and 3.2 M104. IIRC the 2.8 is badged 300E 2.8. The 3.2 is badged just 300E.

Sixto
98 E320s sedan and wagon
02 C320 wagon

Zulfiqar · #14 01-17-2019, 10:36 AM

Quote:

Originally Posted by jake12tech

It has ASR. I’d likely rebuild it. Cheaper than buying a rebuilt I’d imagine. Plus I think I plan to keep the car now since I’ve had zero luck even getting $500 for it. Scrapping it is not an option considering I’d get $150 at a metal yard

Im sure you can rebuild it - just lay it out on a large table and measure everything - basic measure twice cut once type situation.

I believe you can buy some of the older style bosch connectors like the ignition coils, injectors, coolant sensors and their pins too, a cheap AC delco crimping tool will make quick work of it, once you have pinned and wired stuff - you can wrap it in tesa cloth tape to make it look OE german qualitat or you can go japanese style with corrugated tubing and plastic wrap or industrial/marine type wrap depending on your mood as the car is not worth much anyway.

btw - the 93 300E 3.2 was quite a chunk of money pricey compared to the last year (1995)

jake12tech · #15 01-17-2019, 11:42 PM

Well I unloaded the car thank god. It sold for exactly what I had into it. Thanks for the help guys.