Posted By: joelson6
worn fuel pump push rod - 08/10/15 08:45 PM
i'm a little ticked off right now about this. i have a 383 that i did a top end rebuild on. heads rebuilt, new cam, lifters, valve springs, timing chain, oil pump. put it all back together and had it running for about 2 weeks. all of a sudden, i developed a fuel delivery problem, no fuel coming out of the pump. so i put on a new fuel pump and it didn't even work for a day. i take off the pump and remove the fuel pump push rod, it won't come out. can't get anything in there to get it out, so i take apart the the front of the motor and get the timing chain cover off. i get the rod out and the end is worn about a 1/4" (just measured with digital caliper 2.910", should be 3.220") and the end of the rod is concaved. so i take the rest of the engine apart and get the cam out. the lobe for the fuel pump push rod definitely looks worn. i get my old cam, the cam i originally replaced, set the 2 next to each other, make sure the timing chain dowels are both facing in the same direction, and measure both. no matter what direction i turn both cams, the measurements on the caliper are the same.
so what would cause the fuel pump push rod to wear like that? does it spin in the bore like the lifters and for some reason it wasn't spinning? is it only suppose to go in the block one way and i had it in backwards? the fuel pump that was in the car, when i first put it back together, was in the car for 10 years with the old cam, and never had a problem. i'm kind of at a loss with this. the lobes on the cam and the bottom of the lifters all look great, no abnormal wear there. the fuel pump is a stock over the counter replacement, no HP pump.
the new cam (.420/.442), lifters, timing chain and valve springs are Edelbrock stuff. this isn't a HP application either. it's in my '70 Newport, 383 2bbl. and i wanna keep it that way too. it seems to be difficult to find stock replacement cam and lifters for a B/RB engine. I know i'm replacing the cam and lifters, i don't want to get it back together and have the same thing happen with a new fuel pump push rod. Howards cams has a .420/.420 lift cam i'd like to try with new lifters and the fuel pump push rod. but i'm not sure if that will fix the problem. any input would be appreciated.
thanks, Greg
so what would cause the fuel pump push rod to wear like that? does it spin in the bore like the lifters and for some reason it wasn't spinning? is it only suppose to go in the block one way and i had it in backwards? the fuel pump that was in the car, when i first put it back together, was in the car for 10 years with the old cam, and never had a problem. i'm kind of at a loss with this. the lobes on the cam and the bottom of the lifters all look great, no abnormal wear there. the fuel pump is a stock over the counter replacement, no HP pump.
the new cam (.420/.442), lifters, timing chain and valve springs are Edelbrock stuff. this isn't a HP application either. it's in my '70 Newport, 383 2bbl. and i wanna keep it that way too. it seems to be difficult to find stock replacement cam and lifters for a B/RB engine. I know i'm replacing the cam and lifters, i don't want to get it back together and have the same thing happen with a new fuel pump push rod. Howards cams has a .420/.420 lift cam i'd like to try with new lifters and the fuel pump push rod. but i'm not sure if that will fix the problem. any input would be appreciated.
thanks, Greg