Looks like my minds been made up for me about whether or not to keep my old fuel pump or get a new one. My original fuel pump looks like this
and did not have a spacer between it and the engine block. If I measure the distance from the mounting face of the pump to the center of the wear on the camshaft actuating lever I find its 1 1/4" and, as you can see, the rubbed spot is closer to the fuel pump than it is to the end of lever referenced to the center of the foot. Does this mean my fuel pump is "in" too far? Maybe so......but I dunno. What really tipped me off was when I went to mate the fuel pump up to the block. I always wondered why the front mounting plate had that rectangular hole in it......and now I know.......its to accommodate the vacuum pump. Only problem is.....without a spacer between the fuel pump and the engine the oumo is drawn into too close to the engine and the wide part of the vaccum pump rubs against the mounting plate.
So.....despite the decision, both economical and practical, to retain my existing pump looks like I'm going shopping for one that either has the spacer or one that doesn;t have the vacuum pump (which I'm not using anyway.
If you ordered a new correct dual pump you would not get a spacer with it. You need to order the spacer itself. M38 and M38A1 are different. So you'll have to look it up in the parts book.
It helps to always ID the model jeep you are dsiscussing in a topic. An alternative is to go to your profile and fill in a signature element for yourself that includes your jeep model. Like mine below.
Sorry about that.....its for an m38a-1....although I'm not sure of the year. I think its one of the later ones though because it has the single lower mounting bolt for the grill guard and no hinges.
For sure my pump is not an m38a-1 pump......so would the pump I have still work with an m38a-1 spacer.....or.....is the actuating arm long enough to accommodate a spacer?
Here's a pic of the interference.....
and I assume this is a broken valve assembly from the vacuum side of the pump
so I don't think the vacuum pump is operational anyway. I was actually thinking about removing the screw and grinding away the area where the pump interferes.....but then the spacer issue is still a concern......and I did have to replace my cam because the pump lobe was worn excessively.
The spacer does a little more than move the pump out so it doesn't rub the mount plate. The spacer's real purpose is to regulate the output pressure of the pump by setting the relative stroke on the pump lever by adjusting it's fulcrum point on the cam. The spacer is WO# 800361 and it is 9/16" thick.
