Checking Fuel Distributor
 

Hi, This is my first time on the site. I own a 1986 560Sl. The idle is not smooth but runs great in every other way. The determination by some shade tree mechanics is that the fuel distributor is not sending gas to the #2 on the Driver's side and very little to #4 on the passenger side. (it is running lean and hot)

When they open the fitting on the Fuel distributor to those cylinders very little gas comes out, compared to others.

Is there any way of running cleaner through the distributor? Connect a pump to circulate cleaner only, not to run the car? The vehicle was stored for a few months from Feb. to June
2003.

Does anyone have a recommendation for having this one rebuilt? or exchange for a rebuilt one. I am leary of used unless its been tested.

Thanks, Jack Reseda CA

Jack, have you thought of capping all the injection line fittings at the fuel dist. except for #2 and #4, then bridge the fuel pump relay connections to engage the fuel pump? Unscrew the #2 & #4 injectors from the lines and run the lines into tall glasses to catch the fuel. This way you may be able to purge the #2 & #4 openings on the FD, and maybe some rust sediment or trash will come out, clearin up your situation.

Hopefully you will read my last post about my FD issues. Have you cleaned your fuel tank lately? Fuel filter & pumps also..?

I have tried every cleaner you can think of, with no success. If you can find a used FD, just get an exchange warranty at least, that way you can get another one if the first does not work.

I hope you locate the problems soon. Let us know how it turns out. Take care. :)

Jack,
Be aware that when an injector sticks open the intake vacuum will suck the fuel out the line so fast that no fuel will leak at the fuel line. That cylinder will usually have a black/fouled plug, miss at idle but run better off idle. Swapping injectors with a known good cylinder wil help in the diagnose.

FD blues...
 

Hi Jack, I just received your email, but will reply here as well.

If this determination is correct by visual inspection, I would certainly purge the FD via the method I mentioned in my other post:

Jack, have you thought of capping all the injection line fittings at the fuel dist. except for #2 and #4, then bridge the fuel pump relay connections to engage the fuel pump? Unscrew the #2 & #4 injectors from the lines and run the lines into tall glasses to catch the fuel. This way you may be able to purge the #2 & #4 openings on the FD, and maybe some rust sediment or trash will come out, clearin up your situation.

I sent you an email on how to bridge the fuel pumps to purge the FD. If this makes no difference, Paulwho has a good point as well.....either task is about the same amount of work though, so it's your call. But as far as your FD is concerned, it seems to be working...maybe slightly clogged like mine was.

Good luck, and keep us posted.

the first thing i would check is injector flow on those cylinders. more often than not, when there seems to be little flow from the dist with the lines open, the injector is hanging open. swap injectors and try again. it may be running lean due to other factors. good luck, chuck.

My mechanic told me my FD was bad and needed replacing. According to the mechanic this was the reason for not passing emissions. My car also idled a little rough at the time, but not too bad. However, over time the rough idle got worse to the point it was shaking the car. I found FDs rebuilt for nearly $1000.00 and new ones are way out there. I didn’t listen to the mechanic and tried every cheap fix I could. I ended up getting FD on ebay used for $200.00. Now every thing is fine.

There are people that rebuild FDs as well. I'll take the time to get Names and numbers if interested. Or perhaps someone here can suggest such a business.

Jack,

I got mine (rebuilt) from germanstar.net with a year warranty for less than $500 (while the local junk yard ask for $375 for a used one with 1 month warranty). My car did not have any fuel coming out of a cylinder at idle as well.

Frank.