just bought a sl300 and im having some probs

[joewaldrop]

i bought a 300sl and the 1st prob is i took off the hard top and now there is a red switch beeping everytime i start to drive ... next thing is after it sits for a few hrs it takes a couple times cranking it to start then after it does it idles rough for about 2 mins ... then when i hit the gas it dosent feel like theres power til i slam the gas ... i only have 50,000 miles on it ... idk any help would be great thanks

[tecqboy]

Clear the error codes in the soft top controller and reset.

Check the fuel accumulator and fuel filters.

Distributor cap and rotor are due for a change if they are still original. Has it ever had a tune-up?

All of your issues have been often times discussed in this forum in the past. You need to use the forum search tool to look at the threads which address these issues. This is a very complex vehicle but you can do much of the routine maintenance yourself. The information you need is here, but you need to "search" for it. Good Luck.

[joewaldrop]

how can i reset the codes ? .. and i went to auto zone to get a cap and rotor and they said my car doesnt have one ? i bought a fuel filter are they easy to get to ? my car didnt come with the owners manual so i dont even know how to work the soft top lol

[joewaldrop]

oh and the fuel accumulator ? how do i check that

[deanyel]

Making the assumption that your SL300/300SL is actually a 300SL between the years 1990 and 1993 - it does have a cap and rotor, and Autozone is not a good place to be buying parts for it.

[joewaldrop]

lol i figured that when thay said there is no cap and rotor ... you know how much they would cost from a dealer ?

[rocky raccoon]

Best parts source in terms of availability AND price is right here. Phil at FASTLANE (accessible from this site) is our go-to guy.

There is a wealth of information on your car if you use the "search" function. You may also find a subscription to ALLDATADIY and/or purchase of a repair manual on CD useful.

[joewaldrop]

can anyone tell me step by step how to stop the beeping thats going on while i drive ? the top button is flashing at the same time idk what to do

[tecqboy]

Mercedes Soft Top Controller Reset Procedure. R129 1990 thru 12/93.

Locate the diagnostic connector: Under the black plastic cover over the hood-up switch on
the US passenger side of vehicle near the strut mount.

To recover codes from the soft top controller:
Connect a normally open (N.O. S.P.) switch between pin 1 and pin 10. A simple push button switch with leads or a short jumper lead will also work OK.

Short (close switch) 2 to 4 seconds to read error codes.
The lamp in red (operate) top switch ( in the console ) will flash out a number of pulses.
Count the pulses and see the chart.

Short (close switch) 6 to 8 seconds to erase error code.

There may be multiple codes stored, so read / erase until all are cleared or the problem
Is located. Some codes may require reading / resetting twice before they will erase.

The codes that will suspend operation of a soft top on the R129 are 21, 22, 26, and 30.

A code of "1" indicates no faults and no hard top in place, while a code of "20" indicates no faults and the hard top is assumed to be on the car.

2 = Limit switch, LEFT locked, soft top storage compartment cover.
3 = Limit switch, RIGHT locked, soft top storage compartment cover.
4 = Limit switch LEFT closed, soft top storage compartment.
5 = Limit switch RIGHT closed, soft top storage compartment cover.

6 = Limit switch LEFT locked, soft top fabric bow.
7 = Limit switch RIGHT locked, soft top fabric bow.
8 = Limit switch LEFT closed, soft top fabric bow.
9 = Limit switch RIGHT closed, soft top fabric bow.

10 = Limit switch LEFT front locked, soft top.
11 = Limit switch RIGHT front locked, soft top.

12 = Limit switch soft top storage compartment open.
13 = Limit switch soft top fabric bow raised.
14 = Limit switch soft top down in storage compartment.
15 = Limit switch soft top up ( secondary closing speed ).

16 = roll bar retracted switch.
17 = Left window failed to lower (limit switch open), bad fuse, or window relay on controller.
18 = Right window failed to lower (limit switch open), bad fuse, or window relay on controller

19 = Vehicle speed signal to controller missing or illogical.

20 = Hard top installed, no faults.

21 = Controller module / soft top switch circuit open.

22 = Roll bar switch activated.
23 = roll bar control unit not functioning.
24 = Roll bar crash deployed.

25 = contradicting switch inputs.

27 = insufficient voltage.
28 = Speedometer signal is missing.
29 = Wheel speed from ABS control module missing.
30 = Top operation disabled (due to #29).

[sldan]

Joe,

I have a 1991 300SL with 68k miles it had K Miles when I purchased it 5 years ago and I had the same problems you are having. I have fixed all of them and the car runs great.

Replaced injectors to correct the starting problem since the original injectors were leaking after the engine was shut off causing a fuel pressure drop. The pressure had to built back up when restarting.

Replaced the ignition coil, rotor, and cap to correct the stalling problem. This problem acts like a fuel system problem but a bad ignition coil produces a weak spark. The engine would randomly either stumble or stall when trying to move out from a stop light. I also replace the spark plugs with new NGK plug. Do not use platinum.

If you plan to work on this car yourself you must purchase the service CT.

I have purchase my parts from the Phil on this forum.

I also has the top issue and used the LED to check and reset trouble codes and did not have to replace any parts or controller.

I have had and corrected a few of the other standard 1990 to 1993 300SL issues.

Engine hood insulation pad deterioration - replace insulation

Instrument cluster idiot lights operating when turn signals are operated. The dealer replaced mine under the 30 day warranty but there is a fix listed on this forum.

Drive seat back would not unlatch - Adjusted the cable.

AC freon pressure was low but could not find a leak. Has it converted to R34 and is has been OK.

AC vacuum control unit failed causing dashboard vents to revert to defrost. Replace the vacuum control unit.

It is worth while to always do a search on this forum.