I have a bone-stock 1968 valiant, and in 6 months I just had my 4th fuel pump go out. what could be causing this? I went through 3 of the autozone cheapos, and now their "better" one just left me stranded 50 miles from home. Has anybody else had these problems?
Posted By: chache876
Re: fuel pump - 10/04/10 11:38 PM
mechanical? electrical? part #s? more details on the pumps going 'out'...no pressure? low pressure? etc...
Posted By: partfiler69
Re: fuel pump - 10/04/10 11:46 PM
I'm sorry, it's a bone stock /6, with a stock mechanical pump. I took off out of town with it, and it got to where it wouldn't pull a hill. Then it fell on its face on the straitways, then it just quit altogether. everytime time it stopped, it would start right back up after the filter filled back up.
Posted By: StukaJU87
Re: fuel pump - 10/04/10 11:56 PM
Just a thought, maybe there is a leak somewhere in the fuel line between the tank and pump and you are sucking air as the demand for fuel increases?
Posted By: chache876
Re: fuel pump - 10/05/10 12:30 AM
Well please don't take this the wrong way but when I read that you've gone through four of the same fuel pumps in 6 months...that kind of threw up a red flag for me. Is it possible that all four were defective? Yeah its possible, but not very likely...or at least something else had happened that caused all four of those pumps to fail that you need to fix before installing a new one.
Have you checked the fuel pressure AND fuel volume? There could be a a restriction in the line such as a clogged fuel filter or sending unit strainer causing low fuel pressure. Contamination of fuel systems is a major killer of fuel pumps...more common with electric fuel pumps but mechanicals aren't invincible. Dirt, rust and other crap that gets into the tanks will clog filters and strainers very quickly, causing the pump to work harder.
When you removed these fuel pumps did you examine the diaphragm and see if there was any damage? Check your engine oil to see if it smells like gas...if it does the fuel pumps diaphragms are leaking into the crankcase. If the pump gets removed again, shine a flashlight on the fuel pump eccentric and see if it looks worn out.
Autozone rents a loaner tool part #CP9920a fuel pressure testing kit that comes with a pressure tester if you don't have one.
w/ chache, check your car out to find out if there's a problem elsewhere. It's possible you got 4 bad pumps but don't count on it. Good chance your pump is having trouble pulling fuel from the tank due to some sort of obstruction in the line or pickup.