Replace fuel pulsator
Thread Starter
Instructor
Joined: Sep 2015
Posts: 143
Likes: 25
Replace fuel pulsator
Hello,
Had strong fuel smell from rear of car. Car seemed like there was some type of fuel problem ? Can't really explain right now. Tried hooking up pressure gauge had problems, could not get reading , that's another story. I could be way wrong , but after visual inspection while car running. It looked like the pulsator was leaking fuel ??? I replaced with proper rated fuel line and car idles better and drives stronger . Right or wrong ? Pulsators sitting on work bench, see what happens ? Is there some type of check valve in the fuel system . So far everything seems ok ? Read somewhere here about fuel pressure and check valve ? Yes I don't know. Thank you.
Had strong fuel smell from rear of car. Car seemed like there was some type of fuel problem ? Can't really explain right now. Tried hooking up pressure gauge had problems, could not get reading , that's another story. I could be way wrong , but after visual inspection while car running. It looked like the pulsator was leaking fuel ??? I replaced with proper rated fuel line and car idles better and drives stronger . Right or wrong ? Pulsators sitting on work bench, see what happens ? Is there some type of check valve in the fuel system . So far everything seems ok ? Read somewhere here about fuel pressure and check valve ? Yes I don't know. Thank you.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
The check valve is in the fuel pump. If the pulsator was not connect to the lines tight, it could be leaking fuel so your getting little or no pressure to the fuel system. Replace the pulsator with a section about 2" long of high pressure fuel hose that can be submerged in fuel. Use screw clamps to attach the hoses to the fuel tubes in the tank.
Good luck on your Corvette Adventures.
Good luck on your Corvette Adventures.
Team Owner
Joined: Feb 2006
Posts: 23,115
Likes: 117
From: San Antonio Texas
I just replaced my fuel pump. The new pump says it is a turbine style pump and does not require the pulsator (like the roots roller bearing type). It came with a piece of fuel hose to replace where the pulsator went.
Race Director
Joined: May 2006
Posts: 10,691
Likes: 71
From: Phoenix Arizona
While its very possible, maybe probable, you have a bad fuel pump, a bad fuel pump will not cause a gas smell. Keep looking. You may have a bad hose or a requlator problem, or even a bad gas cap. The fuel pump is in an a sealed unit, the gas tank.
Last edited by zr1fred; Aug 4, 2016 at 01:50 PM.
Team Owner
Joined: Jul 2004
Posts: 28,358
Likes: 3,253
From: Hartford WI
Not sure about a regulator since it would suck the gas into the manifold and not throw it out the back where he is smelling it.
Team Owner
Joined: Feb 2006
Posts: 23,115
Likes: 117
From: San Antonio Texas
There is a vent tube that leads to the charcoal canister that comes off the tank where the other fuel lines lines are by the filler neck. Maybe that line has a break in it or is plugged up causing the fumes back there.
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Thread Starter
Instructor
Joined: Sep 2015
Posts: 143
Likes: 25
Thank you !!! Now that you said the regulator may suck gas into intake ? . A light sort of went on . I have checked the injectors numerous times for leakage, and never had any gas at vacuum line on regulator, however , I know it's obvious , But when I open the throttle plates by hand , I know this will sound funny. There is a gas smell from the intake that wound bring elvis back. It could explain so many quirks with the car . I may check it out this weekend.
Team Owner
Joined: Jul 2004
Posts: 28,358
Likes: 3,253
From: Hartford WI
Thank you !!! Now that you said the regulator may suck gas into intake ? . A light sort of went on . I have checked the injectors numerous times for leakage, and never had any gas at vacuum line on regulator, however , I know it's obvious , But when I open the throttle plates by hand , I know this will sound funny. There is a gas smell from the intake that wound bring elvis back. It could explain so many quirks with the car . I may check it out this weekend.
Still, to verify what is going on, see if the system will hold pressure. Turn it to run mode and see what the pressure is and how long it holds.
Thread Starter
Instructor
Joined: Sep 2015
Posts: 143
Likes: 25
The gas smell is finally gone from the back of car, runs better, still more to check out. My backward thinking and I may be wrong ? Is that , if the gas in the tank was being disturbed and or the pulsator was leaking . You would have fumes, I know you will fumes anyway, it's a gas tank, That being a vented cap , and the spill tube on the car. Fumes maybe could happen ? That's my 2 cents.
Team Owner
Joined: Jul 2004
Posts: 28,358
Likes: 3,253
From: Hartford WI
Thread Starter
Instructor
Joined: Sep 2015
Posts: 143
Likes: 25
When you don't open a bottle of soda and shake it around, do you smell the soda? The pulsator and the gas in the tank is sealed up. Either the vent hose is leaking or it is coming from somewhere else regardless of whether there are elves swimming in your tank or the pulsator is leaking.
Instructor
Joined: Mar 2024
Posts: 150
Likes: 1
From: Arizona
Instructor
Joined: Mar 2024
Posts: 150
Likes: 1
From: Arizona
My research seems to point to the fact that there is a fuel line check valve that is near the fuel pump that keeps fuel from flowing back into the tank after the key is turned to the on position just before a start. It is my understanding that this check valve also keeps pressure in the fuel lines, at least for a time, after the engine is turned off. Please let me know if you find out anything different. Some people seem to think that the valve is incorporated in the fuel pump on my 97 C5 but I determined that this is not the case.
Safety Car
Joined: Mar 2017
Posts: 4,188
Likes: 1,308
From: LeClaire Iowa
My research seems to point to the fact that there is a fuel line check valve that is near the fuel pump that keeps fuel from flowing back into the tank after the key is turned to the on position just before a start. It is my understanding that this check valve also keeps pressure in the fuel lines, at least for a time, after the engine is turned off. Please let me know if you find out anything different. Some people seem to think that the valve is incorporated in the fuel pump on my 97 C5 but I determined that this is not the case.
Safety Car
Joined: Mar 2017
Posts: 4,188
Likes: 1,308
From: LeClaire Iowa
I did not know that Good info. Seems as if Chevy quit trusting the fuel pump check valves and decided to add a higher quality stand alone one in the line. Dan