No Fuel Pressure
No Fuel Pressure
My '96 Neon 2.0 SOHC recently got a new fuel pump. as i recall the car had lousy fuel pressure with the old pump and almost no sustained pressure at all when car wasnt running. the car had a problem where i couldnt drive more than 30 miles without it acting like it was out of gas, determined this to be vapor locking, as i had to wait about 20 mins before it would restart. I put in the new pump (steel gas tank) and have driven the car trouble free for about 500 miles now. Now very suddenly the car has decided not to start. when key is turned on i can hear the pump kicking on. when problem first started i was able to use some starting fluid and get it running. Now no amount of starting fluid will get her running and stay running. push in on the schrader valve on the fuel rail, only a couple drops dribble out.
is fuel pressure maintained from the pump output line or by a check valve on the return line? is this definitely a bad pump or could be something else like the fuel rail, a relay, little green men?
im unemployed atm and broke, so randomly replacing stuff is not feasible for me. any and all suggestions, tips, info, help are greatly appreciated.
is fuel pressure maintained from the pump output line or by a check valve on the return line? is this definitely a bad pump or could be something else like the fuel rail, a relay, little green men?
im unemployed atm and broke, so randomly replacing stuff is not feasible for me. any and all suggestions, tips, info, help are greatly appreciated.
Captain
Joined: Mar 2009
Posts: 724
Likes: 1
From: Hazel Green, AL
The 96 model has the fuel pump, regulator, fuel level sending unit, and filter all contained in one unit (as you already know). You say you replaced it with a new one. That is good. Did you clean out the tank too while you were at it?
It sounds to me like you have a clogged filter and or clogged pressure valve, and if that is so, then it means you have some serious crap in the tank.
My advice? Since you have no cash, drain the tank, pull the tank off, clean and flush the tank and the unit. My guess is that once the tank is off and you start cleaning it, you will see some serious crap come out.
PS. There is no return line on a Neon. Once it is pumped out of the tank, it goes straight into the fuel rail, where the electrically activated fuel injectors release a shot of gas for each engine cylinder cycle. The system will remain fully pressurized for a brief time after it is turned off, but slowly bleed down. That is why after you come out a couple of hours later and turn the key, the system will re-pressurize the system in about 1-2 seconds (that quick whizz sound you hear if you are listening for it) when the key goes to the on position, before the crank cycle begins.
It sounds to me like you have a clogged filter and or clogged pressure valve, and if that is so, then it means you have some serious crap in the tank.
My advice? Since you have no cash, drain the tank, pull the tank off, clean and flush the tank and the unit. My guess is that once the tank is off and you start cleaning it, you will see some serious crap come out.
PS. There is no return line on a Neon. Once it is pumped out of the tank, it goes straight into the fuel rail, where the electrically activated fuel injectors release a shot of gas for each engine cylinder cycle. The system will remain fully pressurized for a brief time after it is turned off, but slowly bleed down. That is why after you come out a couple of hours later and turn the key, the system will re-pressurize the system in about 1-2 seconds (that quick whizz sound you hear if you are listening for it) when the key goes to the on position, before the crank cycle begins.
Last edited by bg1995redneon; Aug 25, 2011 at 10:22 AM.
update:
i replaced the fuel filter, when i did that i checked for fuel pressure at the pump. there are 2 lines coming out of the pump and only one pumps fuel. when i put my fingers over the ports and have the key turned on, the pressure on the one side is strong enough to blow my finger off. reconnect everything and disconnect the fuel line at the fuel rail, piddly pressure and car still wont start. still zero pressure at the fuel rail although gas does pump up. i removed the fuel rail and injectors and cleaned them. vehicle will momentary start with starting fluid. is this possibly because the pump is too weak to pressurize the system and its just back flushing the fuel back into the tank through the 2nd port?
i replaced the fuel filter, when i did that i checked for fuel pressure at the pump. there are 2 lines coming out of the pump and only one pumps fuel. when i put my fingers over the ports and have the key turned on, the pressure on the one side is strong enough to blow my finger off. reconnect everything and disconnect the fuel line at the fuel rail, piddly pressure and car still wont start. still zero pressure at the fuel rail although gas does pump up. i removed the fuel rail and injectors and cleaned them. vehicle will momentary start with starting fluid. is this possibly because the pump is too weak to pressurize the system and its just back flushing the fuel back into the tank through the 2nd port?
New Member
Joined: Nov 2012
Posts: 1
Likes: 0
My '96 Neon 2.0 SOHC recently got a new fuel pump. as i recall the car had lousy fuel pressure with the old pump and almost no sustained pressure at all when car wasnt running. the car had a problem where i couldnt drive more than 30 miles without it acting like it was out of gas, determined this to be vapor locking, as i had to wait about 20 mins before it would restart. I put in the new pump (steel gas tank) and have driven the car trouble free for about 500 miles now. Now very suddenly the car has decided not to start. when key is turned on i can hear the pump kicking on. when problem first started i was able to use some starting fluid and get it running. Now no amount of starting fluid will get her running and stay running. push in on the schrader valve on the fuel rail, only a couple drops dribble out.
is fuel pressure maintained from the pump output line or by a check valve on the return line? is this definitely a bad pump or could be something else like the fuel rail, a relay, little green men?
im unemployed atm and broke, so randomly replacing stuff is not feasible for me. any and all suggestions, tips, info, help are greatly appreciated.
is fuel pressure maintained from the pump output line or by a check valve on the return line? is this definitely a bad pump or could be something else like the fuel rail, a relay, little green men?
im unemployed atm and broke, so randomly replacing stuff is not feasible for me. any and all suggestions, tips, info, help are greatly appreciated.
Registered User
Joined: Dec 2005
Posts: 6
Likes: 0
In the soup as well
Well, now this is happening to the wifes neon. I can hear the fuel pump turning on but little pressure at the rail test port (barely drips out when priming-id imaging at 38 psi, it would be spraying out fairly violentsly). I already had replaced the entire fuel module before but that was 3 years ago. Going to start working on it tonight and see whats going on. First going to try back at the pump like Richard did and see if I get the same results. Its its weak there, then its most likely the pump.
One thing I was thinking about was, does the accumulator ever get clogged? This is the silver looking canister inline right after the fuel pump. I noticed ours is in very poor appearance but not sure what the insides look like. Anyway Ill be sure to report back with any developments.
One thing I was thinking about was, does the accumulator ever get clogged? This is the silver looking canister inline right after the fuel pump. I noticed ours is in very poor appearance but not sure what the insides look like. Anyway Ill be sure to report back with any developments.