Fuel Pressure issue questions
Thread Starter
Burning Brakes
Joined: Mar 2003
Posts: 1,174
Likes: 6
From: NW MN
Voltage good to pump. Solid 12 volts
Took off fuel feed line from injector rail and tested flow. Manual says at least 1/2 pint in 15 seconds. Got much more than that so test is good. Just for my own peace of mind I disconnected from feed line from tank and back blasted air from the rail through the line and cleared all gas from the line. Good flow of air on this test and not much debris came out of the line. Filled the line again with gas and blasted back again. Disconnected return line from rail and blasted air to tank. Reconnected feed line to rail and blasted air from tank to the rail. Exercised the FPR with air pressure and blew everything out the return line at the rail. All this was quite messy and catching the gas was a challenge but I gt most of it with rags.
Reconnected and tightened everything back down and ran the pump to fill the system. System filled and built pressure much better and I could here a chatter from the FPR. Released pressure from the system via the pressure gauge and tried to start the car the normal way. Turned the key and the pressure came up but not as fast as hoped, but the car fired up and ran within a few seconds. Released pressure again and this time I pinched the return line up front in the engine bay and pressure came up much faster. Removed the pinched line so everything was back to normal and cycled the key. Now the pressure came up quickly and the car fired right up. Relased pressure multiple time and now the pressure is coming up quickly and the car fire right up.
I believe I may have a intermittent FPR that does not always seal completely on the return line. The system holds pressure but will leak down from 40 to 25 in about an hour. Maybe time to rebuild the FPR but still I'm happy as the car starts 100 percent better now.
I'll report back tomorrow and let everyone know if it continues to work normally.
Last edited by 86Pacecar; Sep 25, 2017 at 09:17 PM.
Team Owner
Joined: Jul 2004
Posts: 28,474
Likes: 3,291
From: Hartford WI
OK, here's the latest:
Voltage good to pump. Solid 12 volts
Took off fuel feed line from injector rail and tested flow. Manual says at least 1/2 pint in 15 seconds. Got much more than that so test is good. Just for my own peace of mind I disconnected from feed line from tank and back blasted air from the rail through the line and cleared all gas from the line. Good flow of air on this test and not much debris came out of the line. Filled the line again with gas and blasted back again. Disconnected return line from rail and blasted air to tank. Reconnected feed line to rail and blasted air from tank to the rail. Exercised the FPR with air pressure and blew everything out the return line at the rail. All this was quite messy and catching the gas was a challenge but I gt most of it with rags.
Reconnected and tightened everything back down and ran the pump to fill the system. System filled and built pressure much better and I could here a chatter from the FPR. Released pressure from the system via the pressure gauge and tried to start the car the normal way. Turned the key and the pressure came up but not as fast as hoped, but the car fired up and ran within a few seconds. Released pressure again and this time I pinched the return line up front in the engine bay and pressure came up much faster. Removed the pinched line so everything was back to normal and cycled the key. Now the pressure came up quickly and the car fired right up. Relased pressure multiple time and now the pressure is coming up quickly and the car fire right up.
I believe I may have a intermittent FPR that does not always seal completely on the return line. The system holds pressure but will leak down from 40 to 25 in about an hour. Maybe time to rebuild the FPR but still I'm happy as the car starts 100 percent better now.
I'll report back tomorrow and let everyone know if it continues to work normally.
Voltage good to pump. Solid 12 volts
Took off fuel feed line from injector rail and tested flow. Manual says at least 1/2 pint in 15 seconds. Got much more than that so test is good. Just for my own peace of mind I disconnected from feed line from tank and back blasted air from the rail through the line and cleared all gas from the line. Good flow of air on this test and not much debris came out of the line. Filled the line again with gas and blasted back again. Disconnected return line from rail and blasted air to tank. Reconnected feed line to rail and blasted air from tank to the rail. Exercised the FPR with air pressure and blew everything out the return line at the rail. All this was quite messy and catching the gas was a challenge but I gt most of it with rags.
Reconnected and tightened everything back down and ran the pump to fill the system. System filled and built pressure much better and I could here a chatter from the FPR. Released pressure from the system via the pressure gauge and tried to start the car the normal way. Turned the key and the pressure came up but not as fast as hoped, but the car fired up and ran within a few seconds. Released pressure again and this time I pinched the return line up front in the engine bay and pressure came up much faster. Removed the pinched line so everything was back to normal and cycled the key. Now the pressure came up quickly and the car fired right up. Relased pressure multiple time and now the pressure is coming up quickly and the car fire right up.
I believe I may have a intermittent FPR that does not always seal completely on the return line. The system holds pressure but will leak down from 40 to 25 in about an hour. Maybe time to rebuild the FPR but still I'm happy as the car starts 100 percent better now.
I'll report back tomorrow and let everyone know if it continues to work normally.
I forgot. I would run a pump wire all the way from the alternator to the pump. That way, if this happens again, we can run the wire immediately and see what happens. I don't know about an intermittent FPR. Voltage might be there but amperage might not.
https://www.motor.com/magazine-summa...ng-march-2003/
