I am looking for some confirmation or clarification with regard to what is and or should be present on my car. I have an '86 240 DL with approximately 290k on the chasis and an unknown amount on the motor that around 5 years ago was replaced.

Going back three of the the five total owners, the car has had a stumble, at take-off after it's been parked and off. This stumble happens once, all things being equal, at the same distance/time, every time, if there is anything consistent about this car, it's this. I know all the previous owners except for the original, one of which is a good friend. This friend purchased the car from the origianl owner and replaced the motor, since they were already servicing the car at the shop that my friend runs. It's my understanding that prior to me owning the car(again), both fuel pumps had been changed, due to failure. In addition, I've changed out the f.p.r and two different fuel pump relay with no change. After doing some research here, I was convinced that my problem was a bad check valve. I ordered a check valve and fuel filter and decided to change both out in hopes of clearing up this problem.

I finally made the time to get under the car and swap out the parts. I lowered the "cage" and began with the check valve. I discovered that the hard line from the pump to filter was not there, instead, there was a short length of fuel line with 1 clamp to the filter and the other to a barbed fitting attached to the check valve on the pump. I know just from what I've read here that this assembly was probably not the way it was originally intended. Next, I removed the check valve/fitting from the pump, as I pulled the check valve out, a small spring/ball piece fell out of it into my hand. At this point I assumed I had found my problem. I next attempted to insert the new check valve. The new part would not fit? I quickly re-installed the old check valve to plug the hole from the pump. I thought I had ordered/received the wrong part and called the parts house who confirmed that there was only one part available?

So finally, my question; is/are there two different sized check valves for the main pump? Or, did someone, at some point, use a different main pump with a different sized accompanying check valve.

I've since acquired the correct hard line to replace the legth of fuel line, new crush washers for the filter but need to figure out the check valve "mystery"(at least to me)

This problem is not as critical as others, however, it would sure be nice to clear it up and check one more issue off the list. Thanks for any help and or input and sorry about the long post, wanted to be clear and provide as much info. as possible.

Antonio