94' Jimmy idles rough the warmer it gets.
#31
02-04-2010, 06:35 PM
Join Date: Nov 2009
Location: Rochester, Indiana
Posts: 251
yea the odds are low for the second one to be bad but it had higher fuel pressure with the second than the first. the ones i tried were the HELP brand but its made by dorman. I ordered the Borg-Warner one so i guess i'll see what happens when it comes in tommorow morning. i lost the receipt for mine too but they looked it up in the computer and got the receipt for me. The FPR is the only thing i can think of that would make the fuel pressure so high. I did hear that dorman isn't very good when i did some researching about it on the net though. hopefully it will be fixed in the morning. If not it would be my luck though. LOL!
#32
02-04-2010, 09:32 PM
hubert hefner & ohsofly
Been following your thread. Hope you don't mind me weighing in. Went to the factory manual about excess fuel pressure. Says to replace the FPR if pressure is above 61 psi. Since you've already had them on and off so many times it probably isn't the problem. The Dorman I put on mine works just fine. You know it's adjustable, don't you? The little center hole is to adjust the fuel pressure. You have to use the pump prime port with a fused jumper to make the pump run to adjust it with the upper plenum off. It's the only way to go though. You can leak check everything at the same time.
The book also tells you to make sure the regulator is working properly by running the pump and slowly squeezing down (pinching off) the return hose (about 9" long just aft of the engine - access underneath the truck) while watching the pressure gauge (obviously a 2 person job). The FPR should regulate the pressure within specs (55 - 61 psi). By the way that's a hell of a pump to put out 80 psi. I don't understand why it goes up when you rev the engine though. It's not supposed to work like that.
PS Got the same fuel pressure test gauge. Sweet, huh?
Been following your thread. Hope you don't mind me weighing in. Went to the factory manual about excess fuel pressure. Says to replace the FPR if pressure is above 61 psi. Since you've already had them on and off so many times it probably isn't the problem. The Dorman I put on mine works just fine. You know it's adjustable, don't you? The little center hole is to adjust the fuel pressure. You have to use the pump prime port with a fused jumper to make the pump run to adjust it with the upper plenum off. It's the only way to go though. You can leak check everything at the same time.
The book also tells you to make sure the regulator is working properly by running the pump and slowly squeezing down (pinching off) the return hose (about 9" long just aft of the engine - access underneath the truck) while watching the pressure gauge (obviously a 2 person job). The FPR should regulate the pressure within specs (55 - 61 psi). By the way that's a hell of a pump to put out 80 psi. I don't understand why it goes up when you rev the engine though. It's not supposed to work like that.
PS Got the same fuel pressure test gauge. Sweet, huh?
#33
02-05-2010, 09:10 AM
Join Date: Nov 2009
Location: Rochester, Indiana
Posts: 251
hubert hefner & ohsofly
Been following your thread. Hope you don't mind me weighing in. Went to the factory manual about excess fuel pressure. Says to replace the FPR if pressure is above 61 psi. Since you've already had them on and off so many times it probably isn't the problem. The Dorman I put on mine works just fine. You know it's adjustable, don't you? The little center hole is to adjust the fuel pressure. You have to use the pump prime port with a fused jumper to make the pump run to adjust it with the upper plenum off. It's the only way to go though. You can leak check everything at the same time.
The book also tells you to make sure the regulator is working properly by running the pump and slowly squeezing down (pinching off) the return hose (about 9" long just aft of the engine - access underneath the truck) while watching the pressure gauge (obviously a 2 person job). The FPR should regulate the pressure within specs (55 - 61 psi). By the way that's a hell of a pump to put out 80 psi. I don't understand why it goes up when you rev the engine though. It's not supposed to work like that.
PS Got the same fuel pressure test gauge. Sweet, huh?
Been following your thread. Hope you don't mind me weighing in. Went to the factory manual about excess fuel pressure. Says to replace the FPR if pressure is above 61 psi. Since you've already had them on and off so many times it probably isn't the problem. The Dorman I put on mine works just fine. You know it's adjustable, don't you? The little center hole is to adjust the fuel pressure. You have to use the pump prime port with a fused jumper to make the pump run to adjust it with the upper plenum off. It's the only way to go though. You can leak check everything at the same time.
The book also tells you to make sure the regulator is working properly by running the pump and slowly squeezing down (pinching off) the return hose (about 9" long just aft of the engine - access underneath the truck) while watching the pressure gauge (obviously a 2 person job). The FPR should regulate the pressure within specs (55 - 61 psi). By the way that's a hell of a pump to put out 80 psi. I don't understand why it goes up when you rev the engine though. It's not supposed to work like that.
PS Got the same fuel pressure test gauge. Sweet, huh?
PS what else would make the fuel pressure so high?
edit: found the pump prime port
Last edited by hubert hefner; 02-05-2010 at 10:04 AM.
#34
02-05-2010, 09:14 AM
hubert hefner & ohsofly
Been following your thread. Hope you don't mind me weighing in. Went to the factory manual about excess fuel pressure. Says to replace the FPR if pressure is above 61 psi. Since you've already had them on and off so many times it probably isn't the problem. The Dorman I put on mine works just fine. You know it's adjustable, don't you? The little center hole is to adjust the fuel pressure. You have to use the pump prime port with a fused jumper to make the pump run to adjust it with the upper plenum off. It's the only way to go though. You can leak check everything at the same time.
The book also tells you to make sure the regulator is working properly by running the pump and slowly squeezing down (pinching off) the return hose (about 9" long just aft of the engine - access underneath the truck) while watching the pressure gauge (obviously a 2 person job). The FPR should regulate the pressure within specs (55 - 61 psi). By the way that's a hell of a pump to put out 80 psi. I don't understand why it goes up when you rev the engine though. It's not supposed to work like that.
PS Got the same fuel pressure test gauge. Sweet, huh?
Been following your thread. Hope you don't mind me weighing in. Went to the factory manual about excess fuel pressure. Says to replace the FPR if pressure is above 61 psi. Since you've already had them on and off so many times it probably isn't the problem. The Dorman I put on mine works just fine. You know it's adjustable, don't you? The little center hole is to adjust the fuel pressure. You have to use the pump prime port with a fused jumper to make the pump run to adjust it with the upper plenum off. It's the only way to go though. You can leak check everything at the same time.
The book also tells you to make sure the regulator is working properly by running the pump and slowly squeezing down (pinching off) the return hose (about 9" long just aft of the engine - access underneath the truck) while watching the pressure gauge (obviously a 2 person job). The FPR should regulate the pressure within specs (55 - 61 psi). By the way that's a hell of a pump to put out 80 psi. I don't understand why it goes up when you rev the engine though. It's not supposed to work like that.
PS Got the same fuel pressure test gauge. Sweet, huh?
#35
02-05-2010, 09:25 AM
Join Date: Nov 2009
Location: Rochester, Indiana
Posts: 251
it runs really rough at idle bout have to rev it to keep it running. My uncle told me that when my cousin had it the fuel tank started leaking and thats when all the problems started. They changed the tank in it and when they took the tank out they cut the rubber hose and "spliced" it back together when they put the tank back in. Yippie... So i wonder if that could be part of my problem. Just found this out last night. He told me that they used the same pump that was in the old tank.
#36
02-05-2010, 10:03 AM
The fuel pressure does not have anything to do with idle or full throttle. It is supposed to be pretty constant being that it's an electric pump independent from and not subject to engine RPM. I suppose it would fluctuate a little given that the volume of fuel required changes the faster you run the engine but my 94 factory manual says the fuel pressure should be between 55 - 61 psi with pump running.
The fuel pump prime port os a wire coming out of the loom near the junction block on the roght side of the firewall. It has a single female connector on it not hooked to anything and the wire should be Gray in color. The manual (and common sense) says to use a fused jumper/ I made my jumper from an in-line fuse wiith an alligator clio on one end and a male blade terminal crimped on the other. I needed another wire to extend it so I just crimped a male blade terminal on one end and a female on the other. I hook it straight from the battery + to the prime port. The pump will run all day if you want. Don't know why someone would cut the hose at the tank. I think the torx bit that came with your FPR also fits the regulator adjustment.
The factory book has some great troubleshooting procedures in it but the test on the FPR is pretty mich all there is for the pressure.
The fuel pump prime port os a wire coming out of the loom near the junction block on the roght side of the firewall. It has a single female connector on it not hooked to anything and the wire should be Gray in color. The manual (and common sense) says to use a fused jumper/ I made my jumper from an in-line fuse wiith an alligator clio on one end and a male blade terminal crimped on the other. I needed another wire to extend it so I just crimped a male blade terminal on one end and a female on the other. I hook it straight from the battery + to the prime port. The pump will run all day if you want. Don't know why someone would cut the hose at the tank. I think the torx bit that came with your FPR also fits the regulator adjustment.
The factory book has some great troubleshooting procedures in it but the test on the FPR is pretty mich all there is for the pressure.
#37
02-05-2010, 12:09 PM
Join Date: Nov 2009
Location: Rochester, Indiana
Posts: 251
Don't know why someone would cut the hose at the tank. I think the torx bit that came with your FPR also fits the regulator adjustment.
The factory book has some great troubleshooting procedures in it but the test on the FPR is pretty mich all there is for the pressure.
The factory book has some great troubleshooting procedures in it but the test on the FPR is pretty mich all there is for the pressure.
Lol. thats why its at my house cause they can't get it to run right. The torx that is in with the regulator was too big, but i figured what the heck a set of tamperproofs may come in handy later on down the road right? I'm gonna go out and mess with it some more after i finish the house work and stuff.(The joys of being laid off). Thanks for all of the help every one.
UPDATE: So i checked the fuel pressure again on the 3rd regulator so obviosly its not the problem, it read 82-85 with pump running and the only thing the "adjustment " screw did was make the pressure hold higher or lower once the pump is turned off (clockwise= higher and counter= lower HOLD PRESSURE ONLY)
I also found 2 kinda heavy wires that run down the frame rail on the driver's side one is red and one is blue and they look like they have been caught on fire. they are kinda melted. Any ideas what these wires are? Does the fuel pump only run one speed or is it multi speed?
i'm wondering if the return line to the gas tank is plugged...... That will make the pressure go higher than the regulator setting which would explain why i couldn't turn the pressure down....
Last edited by hubert hefner; 02-05-2010 at 04:31 PM.
#38
02-06-2010, 10:18 AM
Your pump should run at only one speed since it receives one voltage.
Have no idea what the red and blue wires are for.
If the return line were plugged it could affect your pressure but that's what the regulator is for. Actually if you look at the test for the FPR in my previous post that's what you determine. But I can also see where the thing might be so plugged that the FPR couldn;t adjust that much. If you dosconnected both ends of the line (I know - a real b**ch)you could blow some air through it and find out. I guess you found the prime port. Pretty handy, huh? A litt;e hint in cas you've never had the das tank out is I found that pulling the left tire/wheel lets you get at the fuek fittings easier.
Have no idea what the red and blue wires are for.
If the return line were plugged it could affect your pressure but that's what the regulator is for. Actually if you look at the test for the FPR in my previous post that's what you determine. But I can also see where the thing might be so plugged that the FPR couldn;t adjust that much. If you dosconnected both ends of the line (I know - a real b**ch)you could blow some air through it and find out. I guess you found the prime port. Pretty handy, huh? A litt;e hint in cas you've never had the das tank out is I found that pulling the left tire/wheel lets you get at the fuek fittings easier.
#39
02-06-2010, 10:35 PM
Join Date: Nov 2009
Location: Rochester, Indiana
Posts: 251
Your pump should run at only one speed since it receives one voltage.
Have no idea what the red and blue wires are for.
If the return line were plugged it could affect your pressure but that's what the regulator is for. Actually if you look at the test for the FPR in my previous post that's what you determine. But I can also see where the thing might be so plugged that the FPR couldn;t adjust that much. If you dosconnected both ends of the line (I know - a real b**ch)you could blow some air through it and find out. I guess you found the prime port. Pretty handy, huh? A litt;e hint in cas you've never had the das tank out is I found that pulling the left tire/wheel lets you get at the fuek fittings easier.
Have no idea what the red and blue wires are for.
If the return line were plugged it could affect your pressure but that's what the regulator is for. Actually if you look at the test for the FPR in my previous post that's what you determine. But I can also see where the thing might be so plugged that the FPR couldn;t adjust that much. If you dosconnected both ends of the line (I know - a real b**ch)you could blow some air through it and find out. I guess you found the prime port. Pretty handy, huh? A litt;e hint in cas you've never had the das tank out is I found that pulling the left tire/wheel lets you get at the fuek fittings easier.
#40
02-08-2010, 06:54 PM
Join Date: Nov 2009
Location: Rochester, Indiana
Posts: 251
Well my fuel line that i made had a different flare on it than the jimmy so i wasnt able to use it to test the fuel pressure. But i did blow air through the line when it was still on the tank and it was leaking where they put it back together and i then noticed that they cut both lines so i decided to pull the gas tank out of it today. i dont think they took the front strap bolts out when they changed the tank because i had to break them to get them out. Couldn't even get them out with my 1/2 inch impact. Ended up borrowing my buddys 2ft long swivel head 1/2 Matco ratchet aka "Big Bertha" lol. So im gonna check the line for clogs in the morning, modify the lines and hopefully get it back together, but we'll just have to see though.