New Fuel Pump Issues - Cranks but no start

[RangerRich96]

I recently replaced the fuel pump (about 2 months ago) in my '96 due to low fuel pressure and truck running lean. Truck ran great after replacing fuel pump, but then got sidelined due to a rotted out trans cooler line. Today I replaced a section of the rotted out line and went to start it up and it just cranks over but won't start. I hooked up my fuel pressure gauge did KOEO test, 0 PSI. I got out and tapped the gas tank with a small rubber mallet re-tested KOEO pressure and it went to 30PSI, then proceeded to start it up and it fired right up. However, after about 15-20 seconds or so pressure slowly drops and it idles down and dies. Hit the tank again, same thing, fires right up but then dies. I'm wondering if it's a connector within the fuel pump assembly or perhaps the harness above the tank? Any thoughts? I'd hate to have to pull the fuel pump again. This is a brand new Delphi fuel pump/sender assembly. Any pointers or thoughts really appreciated?

 

[Mark_88]

Could be a connection is loose but I tend to think the pump failed. Like when a starter is going you can sometimes knock on it and it will work for a few times and then no more.

Pump should be under warranty if you bought it new so I'd suggest try returning it if you have that option.

Wiggle the connectors first but if there is no fuel pressure after that I'd contact the store where you bought it.

 

[RangerRich96]

Could be a connection is loose but I tend to think the pump failed. Like when a starter is going you can sometimes knock on it and it will work for a few times and then no more.

Pump should be under warranty if you bought it new so I'd suggest try returning it if you have that option.

Wiggle the connectors first but if there is no fuel pressure after that I'd contact the store where you bought it.

That's what I'm fearing, I purchased it through RA, and these have a lifetime warranty but it sure sucks having to re-do the install. At least I've already moved the bed to get to it the 1st time and coated those bed bolts in anti-seize upon re-installation.

Thanks for the tips

 

[Mark_88]

You're welcome. The hard work is behind you if you've recently removed the bed so just that annoying bit of determining what the problem is.

If it makes you feel any better, I had to replace the fuel pump on my new off the lot Ford Tempo 5 times in 6 years of a 14 year ownership.

I was so fed up with Ford and their wonky fuel pumps that I called customer service and chewed them out because my warranty had just expired and I was a student...Ford covered the work and, oddly enough, the pump never failed after that. So all of those pumps were within the first 6 years of ownership.

I've read dozens of posts from guys that replace the pump more than once in close proximity so there is definitely a potential problem with the pumps. You just happened to get one of the bad ones on the first shot so hopefully this will get you over the issue.

 

[RangerRich96]

Looks like I found the problem. I crawled under the tank and fiddled with the harness connector at the top of the pump and what do you know, truck started right up and runs fine. Maybe one of the pins wasn't making contact in the plug. There was plenty of grease packed in the connector when I changed out the pump and didn't bother cleaning it all out and repacking. It appears to be a green? dielectric grease they used from the factory. t

 

[Mark_88]

Great news...thanks for the update...