560sel driveability problems
 

Hello, I recently purchased a 89 560sel with 145,000 miles.
within 3,000 miles it developed transmission noise so I had it rebuilt.The engine uses some oil, I have seen a puff of blue smoke ocasionaly when leaving a light. The engine has a miss at idle, especially when cold.
Sometimes when starting hot, the engine starts but won't rev up for the first 15 seconds or so. I tried new cap, rotor, wires, platnum plugs, and fuel filter. No change. That is how it was before the transmission rebuild.
Now after the rebuild I have found that at just about 3000rpm
and full throtle, the engine just bogs out. If I come off the gas for just a second, she is back full. This is in any gear. All the other conditions still exist except the front pump on the transmission no longer makes noise.
I would apreciate any input on this and hope to be of service to the forums members in the future. Thank You, Robert

"Sometimes when starting hot, the engine starts but won't rev up for the first 15 seconds or so"

It's your fuel accumulator - change it.
Morris

Your smoke and skip could be a guide walking in a head as well.



Joe

Morris, thank you. I now have an accumulator on order.
Joe, I suspect the valve guides need replacing and will work on finding out for sure. I thank you as well.

I don't think platnum plugs, are right for that engine either. Stick with regular plugs, and change them every 30K.

Robbert - I agree - get rid of the platinum plugs and go to good ol' copper - could help alleviate the miss at idle.

So, goodby platnum plugs, hello copper. Will try. Thank you.
Robert

Should I expect that changing the fuel accumulator and plugs back to copper will effect the 3000rpm bog down thing or is there something more I should be looking into? It only happens at wide open throtle like when I am on a hill and want to pass. The transmission shifts down and rpm rise quickly to 3000 and than it just bogs down. Could this be caused by the fuel accumulator as well?
Thank you for your help.
Robert

Hi Robert,

my guess is that you do not get enough fuel to sustain more than 3000 rpms. The accumulator is there to help to keep the pressure up, but I wonder if your fuel pumps make enough pressure to sustain higher rpms.

When I replaced the fuel pumps on my 87, I routed the fuel hose wrongly with a kink in the hose and had exactly the result you describe.

Those are the surprises of buying 14 year old cars, my money is on the fuel pumps.

Good luck

Reinhard Kreutzer

Reinhard,
Thank you for your input I appreciate it.
One thought I have is if it were the fuel pump would run at OVER 3000 rpm just fine? It only falters AT 3000 with a wot. Anything above or below 3000 or any rpm that the throtle is not wide open
and it runs strong.
Again thanks for your thoughts.
Robert

Sorry Robert,

I misunderstood and thought you couldn't get above 3000 rpms.
I do not know what would cause a stumble at WOT.

Reinhard

Double check your distributor cap and rotor - look for any carbon trails or slight cracks inside the cap . Even though they are new - double check them. This year I have had several new parts that were defective on diferent cars - the latest was a new front wheel bearing on a Jetta - when installed it worked for 2 days then the bearing had play - replaced it again and the other new one is working fine after 5 months. Just a thought - under load your ignition system is working the hardest. Another possibility could be your coil. Just out of curiosity - has it been rainy and damp where you are when this occurs? If so - definately check cap, rotor and coil. One other thing to check is to idle the car in a dark garage or outside at night and lift the hood and look for sparks along ignition wires etc.

Morris,
I took a close look at the fuel system and I see some potential problems. On what I think is a fuel distributer there is a small black box with wires coming to it (please excuse my ignorance of the proper terms) It is leaking gas slowly out where it attaches to the distributer and maybe out a small crack.
Back at the fuel pumps it is also wet with gas. There is a cowel around the pumps and gas is puddeling in it. The wires are sitting in gas, can you beleave that. Good thing I am looking. My michanic told me that he droped the gas tank to change the fuel filter but it looks to me that the fuel filter is sitting on top of the fuel pumps. Am I wrong?
I took it out for a test this morning and determined that at ANY rpm over 3000 she bogs down.
I will check my cap right now and the wires tonight.
It rained "cats and dogs" here yesterday and I will check the cap carefully.
Your willingness to help is refreshing, Thank you
Robert

Hi Robert,

it will look like this.

Mine leaked right through the terminal and I replaced both pumps, filter, accumulator and the hoses except for the one I couldn't get loose at the tank.

Your mechanic does not seem too familiar with MB's, because you are right, the filter is between the pumps.

I try to find a picture of the EHA, which I believe is the black box leaking under the hood. They also have a habit of leaking.

Reinhard

This would be the EHA valve