Long crank when hot on 380 sl
 

My question is this do the Mann fuel filter have the one way valve that controls fuel pressure. I am having an issues with long crank when hot. It's fine when cold. After it starts when hot it run fine.
Thanks

Time for a fuel accumulator.

I have seen this. A quick tap of the pedal helps, which told me that air flow was off. I adjusted that with an allen wrench through that hole in the air filter housing. Don't adjust much, keep a log of your turns, like 1/8 CCW drive and see how it starts next time. I just drove around oveer my normal course for a few days with the tool handy and kept adjusting until I hit the sweet spot. You have to push past the spring load to engage and cause an effect to the baffle position.

I have diagram at home if you need it. some one here can probably get this to you faster.

The check valve is not part of the filter; there is a check valve at the outlet of the fuel pump.

The accumulator is but one of four points at which residual fuel pressure can leak off.
The other three are:
- Check valve at fuel pump outlet.
- Check valve in fuel pressure regulator.
- Check valves in nozzles.

This is what I know so far
1. Fuel filter has been changed with new one
2 Accumulator changed with a new one
3 Fuel pump changed new one
4. Fuel distruabtor rebuilt one
Still having long crank when hot . Starts and runs fine when cold

How long of a crank are we talking? I sometimes have to crank for a second or two longer when hot.

If yours is longer than that, I would look at your injectors. Both primary and the cold start.

Cold start injector is easy, remove it and place it into a jar. Seal the whole with some big plastic bag. Start the car. If it drips, you found your leak!

The main injectors aren't so easy and require a partial teardown of the top to get at. Lots of little odds and ends that should be replaced while you're in there as well.

Adjusting the air is easy, and worked great for me.

Why not try before you start tearing things apart?

We should note that adjusting the screw in the mixture lever/control plunger lever changes the position of the fuel metering plunger relative to the air flow sensor plate, and hence changes the air-to-fuel ratio. It does not change the air flow, rather, it changes the fuel flow.

It's a good suggestion, but a loaded one without the right tools as the mixture screw is stupid sensitive to even 1/16 of a turn.

Messing with the mixture screw without analyzing the duty cycle from the ECU or CO2 from the tail pipe in an effort to compensate for air leaks or bad fuel pressure can cause all sorts of mischief. It is a great way to fail emissions (if you live in a state that does them), get poor performance, and add to the likelihood of destroying your catalytic converters.

The screw should be the last item one touches when getting this system in tune considering how it is possible to go from running to too rich/lean to start by turning the screw more than a 1/4.

Guide worth reading: K-Jetronic WITH Lambda Overview and Adjustment - Mercedes-Benz Forum

Avoid the temptation to mess with this unless you've got the corresponding tools to correctly interpret what's going on.

Worked for me. I kept good notes all way the from the starting position and completely lost that warm start issue. Mine was warm, not hot. The problem came when it sat a while and cooled down but not cold. I think it drives more responsively now and the mileage is good as ever. put some masking tape down and mark your allen wrench original position, and each adjustment. easy peeeezy no risk.

I had the most persistant hot starting problem when I first bought my wagon. Did everything that could break or wear out and never phased the problem. Turned out that the problem was caused by someone previously screwing with the air horn plate. They had gotten it off center and it was binding in the airhorn before returning to the zero position. This was causing more fuel to flow than the hot engine needed, but the cold engine started fine with the rich mixture.

The moral, check and make sure your air flow plate isn't binding in the air horn due to somebody previously futzing with it.

Just this week a fellow tech was trying to diagnose a hard hot start. Within 10 seconds I pointed out a 1.5mm gap on one side of the plate and a bind before coming back to the zero position.

Now would be a good time to mention this for anybody who may read it. Don't ever take the plate off of the arm, or even loosen the screw. There is no reason whatsoever to do this... ever.