i have 1991 w250 non ic. It has been acting up for a month or so. Some times when i shut it off and set for a day or so it wont start. I have tried several things i read on here. I checked the solenoid its ok. Just replaced module in tank. It rusted up and i got all of rust in furl filter. Replaced all the lines and installed new lift pump. I seem to be getting fuel at all injectors. when i try to start i am getting white smoke sometimes, black smoke sometimes, and no smoke. I guess i am thinking some thing wrong with injection pump. It turns over good. Seems to not be firing sometimes. Not sure what to do next.

 

how long does it sit between starts? when it would run?

 

I would start with the simple things first, before condemning the Ip. Although it probably doesn't explain the smoke, make sure that you have a good connection on the FSS. Some guys change the terminal to an "eye" type for a more secure connection. Then make sure that you are not sucking air into the ip, good luck...Mark

 

It might be time for a professional evaluation of the IP. Your other thread dealt with a real rusty fuel pickup. It takes water to make rust. A little water will suspend in the fuel, especially if some fuel additives with a bit of alcohol have been used. Also fine rust particles can get through the filter, and they are very hard and sharp. Over time, the combination would be expected to take the goodie out of the Injection pump.

Others more knowledgeable can maybe chip in. Don't know if this problem can be dealt with under the shade tree.

 

got it to start tonight. Not sure what i did. just playing around and keep cranking on it. One thing i noticed every time after i finally get it started around the throttle shaft it gets real wet with fuel. but after it runs for a while it don't leak any more. It usually sets 2-4 hours after i have it running and then it don't start but don't do it every time. I am not sure if i should just take the pump off and get rebuilt or what to do.

 

Mine acted funny for about a month then one day it quit dead on me
and had to get towed home.
Turns out the rotor shaft drive lugs in my pump sheared.