So I bought a 2000 honda civic dx 5-speed and after having it awhile my mechanic told me the fuel pump and fuel tank were really old and dirty. I replaced both and noticed that after driving about 230 miles (i can usually get around 325-350 on a full tank) the car has trouble starting. You try to start it and it just doesnt for an extra 1-2 seconds. The less fuel thats in the tank the longer that delay is. Also if I have trouble starting it but drive somewhere and turn it off and turn it back on again within maybe 30 minutes to an hour it will start no problem. Somebody recommended i change the fuel filter and I did and that helped now i can drive about 300 miles instead of 230 before it starts having trouble starting but the problem is still there. I did some research and found other people have this problem with a number of different cars (Hard starting when gas tank low). I found out that if i turn the key to the on position without starting the car and let the fuel pump build pressure for a few seconds I’ll be able to turn on the car with no issue. That works fine and the car works fine but I’m trying to find a more permanent solution. It seems the fuel pump just won’t consistently hold pressure while the car is off and the fuel tank is low where as the old pump seemed to be able to do that just fine. The people at autozone insist I have the right pump model for my car (spectra premium fuel pump hanger assembly part number: B8341H) and the mechanic insists its installed correctly. Does anybody have any insight as to what is the root of this problem and how to actually permanently fix it?
The fuel pump you installed is bad.
What’s more plausible? A couple of companies supply all the fuel pump assemblies to the car manufacturers & aftermarket replacements and one mfr is having systemic issues with anti-drain back valves OR 95% have a “compatibility issue”…
i guess that was a stupid reply from me its just calling the whole fuel pump just bad as a whole when most of the time its working just fine without any reasoning or further explaination doesnt seem like much of a diagnosis. and doesnt let me know at all if there is a small part of the pump i can fix or if i just have to pay to have the whole pump replaced. but you giving an actual part of it that would be bad while explaining why the rest of it works fine makes alot more sense. im guessing the anti drain back valve is whatever is supposed to keep the fuel in the pump while the car is off so it can start immediately without drawing it back out of the tank? and is that replaceable or you have to replace the whole pump?
Needlessly replacing fuel pumps
A lack of fuel pressure will cause a vehicle not to start but a no-start does NOT necessarily mean the fuel pump is bad. Dozens of things, other than a bad fuel pump, can prevent an engine from starting. A lack of fuel pressure does NOT necessarily show a bad fuel pump.
Modern vehicles have several things that can disable the fuel pump. Security systems often cut power to the fuel pump if they think someone is stealing the vehicle. Even oil pressure switches can disable the fuel pump on some vehicles. Experts estimate as much as 50% of all fuel pumps replaced are mis-diagnosed. Fuel pump replacement does not solve the problem as the pump was not the cause.
would a honda sourced fuel pump work better than a non honda sourced one? your old one worked at least. old but dirty. but working. i bet the inside of the tank looked fine
Most often, the anti-drain back valve is built into the pump assembly as part of the pump mechanism that is bolted to the pump motor. They don’t sell pumps separate from the motor because it wouldn’t be economical to sell them separately. If the problem started right after installing the new pump and you don’t have any other drive ability problems, it is likely that the pump itself is bad. Did you pay someone to install it? There are usually materials and workmanship warranties provided by professional shops to cover this type of problem. If so, I would call them immediately to let them know you’re having trouble.