Mechanical Fuel Pump Install - HELP!

[MikeeH]

I never professed to be an engine tech and there are days like today that I think someone should just take all my wrenchs away from me and bury them somewhere that I'll never find them! Anyway.......

The mechanical fuel pump on my 1988 Mercruiser 165 HP (3.7 ltr) failed at the end of last season... diaphram leaks. No big deal, I think. I remove the fuel pump, Carter P/N 60337 and order a new one. Today I tried to install the new one but it won't seat properly. Then, comparing it to the old one I see that the arm which rides on the cam is different. The arm on the old one is straight while the new one has a little elbow bend in it. Part numbers stamped on both pumps match... WTF? The arms are the same length and the part that rides on the cam seems to match so maybe the bend is just some update. I try again.. no good. So, I try the old one and it won't seat properly, either. Go to the aftermarket repair manual and it offers nothing more than, "Install the fuel pump." Big help! So, I'm thinking that its the cam lobe and maybe the cam needs to be rotated so that the lobe is at a position that it isn't putting pressure on the fuel pump arm. Does that make sense?? I can post pictures of both pumps tomorrow night if that helps.

TIA!

 

[mdoherty]

Yes, you are riding on the lobe. You can rotate the engine or just let the cam depress the lever when you snug it up.

 

[Stephen]

What's also fun is that the pump shaft will fall down and get in the way when you install the new one. I like to slide a hacksaw blade behind the housing to hold it at bay while I know others slop a glob of grease to hold it. Either way will help keep it in place.

 

[j-d]

This is a MerC-made aluminum 3.7L inline 4-cyl. Not sure it has a pump pushrod like the "Chevy" V-engines...
But pushrod or not, the cam being on the high side can make the pump very hard to seat in place.

 

[MikeeH]

Yep, got it. Had to turn the crank about a half turn to get the cam lobe on the low side before the pump would get close enough so that I could crank it home with the bolts. Still a PITA but its done. Thanks guys!

 

[mandm1200]

Something as simple as changing a fuel pump, becomes a problem when doing it the first time. It takes me 2-3 times longer to do a project the first time around. After that, its usally pretty good. I just got a fuel pump for my Merc 7.4L; the one that mounts to the sea water pump. The old one has a bad diaphram. No one sells a repair/rebuild kit for it. Nothing automotive (repair kit) matched up to it. Had to shell out $150 for a new one.