500 Sel Hesitation
 

I have this '84 500 SEL. After a complete paint job, the body shop managed to get water inside my gas tank. Well, after a new fuel pump, filter, accumilator, 8 spark plugs and a good used fuel distributor, I am still having problems. If I leave the c/o level slightly high, cars starts up like a champ. I mean it starts right up and is smooth all until you try to accelerate. Then it starts to back fire and pop for about a minute or two. I live in South Florida so temp. here is never really that cold. The car feels as it it is starving for gas. I've got good fuel pressure, all the filters are clear. Timing is set, no vacuum leaks, just cant figure out why it takes long to warm up. What am i missing?

Now if I lean the car a little bit it takes for ever to start, but seems to warm up a bit quicker. I am a little confused on what elso to look at. Does anybody have any ideas that I can't think of.?

Thanx in advance .

What do you mean you lean it out? How do you adjust the mixture? Would you mind telling me how you got the car to start in first gear. My '84 500sel pings like crazy on full throttle starting at 3000 rpm!! So I don't rev it up, but it would be nice to be able to sometimes. Any idea?
Woody

Is the frequency valve buzzing? You set the mixture, what duty-cycle?

Obviously if you set the mixture properly you would be able to answer these questions. I am most curious due to the symptoms to know about the frequency valve.

The frequency valve is buzzing Steve. As far as the duty cycle I tried to leave it at 50/50 but on the scope it dont seem to cycle that way it somtimes at 50/50. Somtimes goes 30/70. Do you think a damaged frequency could give me a problem like this. That is probarly the only thing I did not replace on this injectiom system? Any thoughts?

The freq valve drops the lower chamber pressure to control mixture. usually confirming that it is buzzing is all that is necessary. It does have to flow like an injector though. Try unplugging it. It should run distinctly different on the road without it. It will lack power but otherwise be smooth.

Proper fuel control and proper adjustment is dependant on achieving closed loop control of fuel. It doesn't spound like that is taking place. be sure your fuel pressure is constant and around 70psi.