Fuel pump broke, why? and about the new ones

[Stanley]

Almost 2 weeks ago drove my car home from the shop with the new engine. Fuel pressure was a little low, about 3.8 psi instead of usual 3.9. Mix was way rich so leaned it out a quarter turn. Next day went for groceries. It was running OK. Saw the fuel pressure gauge reading wobble, then drop to zero. Drove a couple more blocks and ran out of gas. Next day ordered a Delphi MF039 mechanical F.P. on amazon. Review said it's original type, not stamped metal. Then I saw a cheaper one, a GMB 550-8040, on ebay from a local shipper. Bought it since it would get here sooner. I figured since it was so cheap I'd get another one so maybe I could use the parts to rebuild my Kyosan Denki or the old Nikki.

They all got here last week, had to work so didn't look at them until yesterday. The GMB's both came in boxes that showed stamped metal F.P.'s but they were the original type. Delphi was the same. The Delphi has yellow zinc plated screws, so I was going to try that one since I like yellow zinc. But lever didn't feel like there was any resistance, like maybe it wasn't doing anything or hadn't been lubricated, so I selected a GMB to install. All three had the same little defect in the casting that shows the cast parts are all from the same mold. All made in Korea. The Delphi had an odd chunk of metal stuck to the side so I guess quality control isn't too picky.

So today I pull the old F.P. off and guess what ? The lever arm was broken just outboard of where the spring attaches.  Both sides of the "U" were broken up to the part that connects them. It's a rebuilt Kyosan Denki that I bought at autozone about 2010.   Wonder what happened to make it break like that.

 

[Mark Maras]

 Probably a dumb question but did the old pump have the spacer under it? If it did, I'd have to chalk it up to metal fatigue.

[Stanley]

Yeah probably. Maybe it was just its time. It has the spacer. Hope it doesn't have anything to do with the new engine, don't see how it could.

Gotta get that car to the carwash.