yep, my FPR is on the fuel rail, about 50 bucks at O'reilly's. Tried the punch on the ring; just not enough room for good whacks and too much rust. Also, whoever the dickbag was before me that put the hoses on it put the screw heads of the hose clamps facing up, right into the unibody, so loosening them would be not fun.
-
Welcome to the new NAXJA Forum! If your password does not work, please use "Forgot your password?" link on the log-in page. Please feel free to reach out to [email protected] if we can provide any assistance.
weird up and down idle, long start (can't find identical symptoms thru search)
- Thread starter cletus141
- Start date
dan1977p
NAXJA Forum User
- Location
- Virginia Beach, VA
Remove them from the filler side and snake them out when dropping the tank.
- Location
- MilkyWay Galaxy
What tool, where, part number, who?? I have searched for 40-60 hours this entire year looking for one.
dan1977p
NAXJA Forum User
- Location
- Virginia Beach, VA
I saw mention of the lockring tool on another thread. I'd never use one so I don't have any part numbers to help you out. It's just a spanner wrench so a couple minutes with a hole saw, DOM, 3/16 plate and a welder could net you the same thing.
Well, a new fuel pump didn't do the trick. Now I'm getting no fuel at all. Grrr. But before I dropped the tank, I tested pressure with the return line clamped and still wasn't getting pressure higher than 10-12psi. The pump was pretty straight forward once I had the tank out. Most difficult part of that was the filler hoses and neck, snaking them through the hole in the unibody. Hooray ratchet straps.
How could I have fvcked that up? It was two wires and a hose. I followed the manual. I did buy the pump without all the stuff attached. And it still primes for a second or two like it did before. I tried a new relay. No luck. Does the computer control if the pump actually pumps? Grrr
How could I have fvcked that up? It was two wires and a hose. I followed the manual. I did buy the pump without all the stuff attached. And it still primes for a second or two like it did before. I tried a new relay. No luck. Does the computer control if the pump actually pumps? Grrr
8Mud
NAXJA Forum User
- Location
- Central Germany
Something I do is check the voltage at the pump. Too many times I've had a low voltage issue.
The system is, first prime, then ballast resistor bypass during start or WOT (ballast resistor bypass relay), then fuel pump relay and through the ballast resistor during run.
There is also like five connectors between the engine bay pump wiring and the pump and the ground!
You mentioned two wires, don't get the sender wires mixed up with the pump wires. At least one after market pump I've changed out had wire colors that didn't match the existing chassis wires or the OEM pump wires. The pump side wires (at the connector) don't usually all match on the OEM pump either.
Should be near battery voltage to the pump during cranking. And lower voltage during run, the voltage varies with demand typically 10 volts or so and is regulated by the ballast resistor.
Just some perspective, I've swapped out one pump, but half a dozen times I've found either relay socket corrosion, connector corrosion, bad ballast resistor, corroded ground or some other problem. Ohm check your head to firewall ground and the block to battery negative ground.
The fuel filter, take it out and let it back flow with brake cleaner spray or whatever. You upset the tank and the filter can plug up quick. I don't put a new filter in there until after I've cleaned the old one out numerous times, after dropping a tank.
If all else fails blow through the fuel lines with air. I've gotten an amazing amount of gunk (jelled gas or rust flakes) out of them before. Usually on an XJ that has been sitting for a long time.
The system is, first prime, then ballast resistor bypass during start or WOT (ballast resistor bypass relay), then fuel pump relay and through the ballast resistor during run.
There is also like five connectors between the engine bay pump wiring and the pump and the ground!
You mentioned two wires, don't get the sender wires mixed up with the pump wires. At least one after market pump I've changed out had wire colors that didn't match the existing chassis wires or the OEM pump wires. The pump side wires (at the connector) don't usually all match on the OEM pump either.
Should be near battery voltage to the pump during cranking. And lower voltage during run, the voltage varies with demand typically 10 volts or so and is regulated by the ballast resistor.
Just some perspective, I've swapped out one pump, but half a dozen times I've found either relay socket corrosion, connector corrosion, bad ballast resistor, corroded ground or some other problem. Ohm check your head to firewall ground and the block to battery negative ground.
The fuel filter, take it out and let it back flow with brake cleaner spray or whatever. You upset the tank and the filter can plug up quick. I don't put a new filter in there until after I've cleaned the old one out numerous times, after dropping a tank.
If all else fails blow through the fuel lines with air. I've gotten an amazing amount of gunk (jelled gas or rust flakes) out of them before. Usually on an XJ that has been sitting for a long time.
- Location
- MilkyWay Galaxy
Did you replace the FPR yet? Is the pump running? If yes, could the pump output hose have come loose in the tank?
Tried checking voltages at different stages (prime, start, run, etc.), but didn't have a second person. I did read someone had bypassed the ballast and ballast bypass relay, essentially running 12V directly to pump; the ballast drops voltage for quieter operation, but that it runs at 12V at startup and WOT. So I decided to try that to see if the pump would run. It sure did. No fuel coming out though.
Dropped the tank and I fvcking hooked it up backwards. The replacement wasn't clearly marked and I installed it in the same orientation as original. Nope. After pulling it I was able to see small + & - symbols. But opposite orientation, so be careful. Tested it on the ground and I got fuel. As a DC motor, it was just running backwards. I wish I would've tested it by just switching power and ground before I dropped the tank, though I would've had to drop it anyway.
I ran out of time at that point. I know certain pumps don't like to run backwards or dry. I hope this isn't the case with fuel pumps. Anyone know? I plan to put it in and test fuel pressure tomorrow. But now I know the pump will move fuel. If I get it all hooked up and it doesn't work right, then I'll chase down the electrical problem.
Dropped the tank and I fvcking hooked it up backwards. The replacement wasn't clearly marked and I installed it in the same orientation as original. Nope. After pulling it I was able to see small + & - symbols. But opposite orientation, so be careful. Tested it on the ground and I got fuel. As a DC motor, it was just running backwards. I wish I would've tested it by just switching power and ground before I dropped the tank, though I would've had to drop it anyway.
I ran out of time at that point. I know certain pumps don't like to run backwards or dry. I hope this isn't the case with fuel pumps. Anyone know? I plan to put it in and test fuel pressure tomorrow. But now I know the pump will move fuel. If I get it all hooked up and it doesn't work right, then I'll chase down the electrical problem.
Welp, I guess it was the fuel pump. At least now I know where the ballast resistor and its relay are. ...And the FPR.
Put the pump back in after rewiring it. Put the tank back in. Again, ratchet straps were huge for this. I used 3: 2 to hold it up at an angle so I could thread the filler and return hoses through the smallish oval slot in the unibody, and the 3rd to pull the tank to the drivers side once I got those hoses lined up. The only real bitch about dropping the tank is that there is no room to get to the hose clamps of those hoses on the tank side. If there was, it would be easy peezy. They are just barely flexible enough the way I did it.
Got everything connected back up, primed it a few times and she started in like 5 seconds once the lines filled up. Let it run for a few to see if the original hiccups were still there. Nope. Pushing 33psi too. Stoked. If only I hadn't wired that stupid pump backwards, I'd've had it done days ago. Be cautious of that, future readers. I installed it in the same orientation as the stock pump because I didn't see the tiny little fvcking +&- molded into the new one.
Thanks for the help guys. I wish more posters followed up with their problems. I hate searching for issues and it sounds liked mine, but they never posted the results.
Put the pump back in after rewiring it. Put the tank back in. Again, ratchet straps were huge for this. I used 3: 2 to hold it up at an angle so I could thread the filler and return hoses through the smallish oval slot in the unibody, and the 3rd to pull the tank to the drivers side once I got those hoses lined up. The only real bitch about dropping the tank is that there is no room to get to the hose clamps of those hoses on the tank side. If there was, it would be easy peezy. They are just barely flexible enough the way I did it.
Got everything connected back up, primed it a few times and she started in like 5 seconds once the lines filled up. Let it run for a few to see if the original hiccups were still there. Nope. Pushing 33psi too. Stoked. If only I hadn't wired that stupid pump backwards, I'd've had it done days ago. Be cautious of that, future readers. I installed it in the same orientation as the stock pump because I didn't see the tiny little fvcking +&- molded into the new one.
Thanks for the help guys. I wish more posters followed up with their problems. I hate searching for issues and it sounds liked mine, but they never posted the results.
- Location
- MilkyWay Galaxy
Great, and thanks for the update, can you give more details on the reinstall issue, using come-a-longs... where did you attach them, and how? I need to drop an 89 soon, my first time and I am worried about the filler tube and vent line on it. Also mine is 1/2 full of gas. I do have a transmission jack I plan to use. And thanks for +/- fuel pump warning!!!!!
Now all I have to do is make a new tank strap bolt because one was so rusted on that it snapped as I twisted even after 2 days of PB Blasterin'. I bought a 3/8-16 X 10" carriage bolt from Home Depot for a buck or two and I'm going to try to bend the head with a torch and vise. I might try to figure out how to use my hydraulic press to bend it. If I can't get the bend close enough to the head, I also bought some all-thread 3/8-16 x 12" that I can bend with more leverage, then cut, and use a jam nut as the head or just bend it to an actual J shape.
Ecomike:
WRT the use of ratchet straps, I used 2 roughly where the tank straps would go (vertical straps). The indentations for the metal tanks straps make good places to grip the ratchet straps. I had to move them around some though as you have to have the tank to the passenger side practically all the way to the tire in order for the hoses to clear. There a several places to attach hooks underneath the Jeep. The 3rd (horizontal) strap I merely wrapped around the passenger side of the tank (top or bottom of the seam, I did top the first install, bottom second. Both worked and I did whichever was convenient at the time) and attached the hooks to anywhere on the driver side.
The tricky part was getting the tank to sit diagonally with the hose ends right at the oval hole and the passenger side nearly at the tire and touching the ground. I had both vertical straps shifted to the passenger side a little so the tank would hang in that spot without having to be held in place (though the hoses can pretty much hold it but will be harder to move if you go that route).
At this point, I ratcheted the horizontal strap slowly until the hoses were contacting the unibody or penetrated the oval hole if you have it lined up perfectly. I didn't have it lined up perfectly, so I would ratchet once, jamming the hoses into the unibody, and use their flexibility to bend them up into the hole. You cannot just ratchet horizontally at this point. I had to incrementally ratchet horizontally, then fix the hose ends, repeat until the ends were all the way through the unibody's oval hole (otherwise the hoses will dig into the top wall of the hole). But once they are through, it should go smoothly the rest of the way horizontally, though it will still take some effort. But when you get the hose ends through the hole you want to start ratcheting the vertical straps as you ratchet the horizontal strap so the tank will get level instead of diagonal.
As you do this, the passenger side of the tank will have to clear the leaf springs, then the "frame rail" of the unibody. I did have to move my vertical straps once each during this process, so a 4th strap will come in handy (though I only used three. Once I got it pinched vertically to hold it in place, I used the horizontal strap in a new vertical position then pulled one of the vertical straps off and used it in a new position for the other side of the tank). At this point I put the 2nd placement of the vertical straps where metal tank straps would go, simply because the indentations of the tank make for good holding places for the straps. But you will have to move them to get the tank straps on.
Getting the filler neck off the first time was kind of a bitch. Wear gloves. i cut myself on the rusty cover without. Getting the filler and return hoses back on the neck is kind of a pain, but at least you can access the hose clamps on that end.
Alternatively, I was considering never disconnecting the filler neck and dropping the tank slightly until the tank side hose clamps were sort of accessible. I didn't realize this until the second time I had to drop it, but I was already comfortable with the other way. The issue is the tang on the filler neck that slides into a strap. But I think you could slide the hoses and neck all the way down to the hole in the unibody if you can get the tang out of the strap. That may provide enough room at the tank to get to the hose clamps.
I tried to use a floor jack earlier, but the straps proved handier due to needing to get the tank diagonal. I would drain the tank, though not totally necessary. I had about a quarter tank and I didn't drain it.
Was that clear enough? let me know if you have any more questions.
Ecomike:
WRT the use of ratchet straps, I used 2 roughly where the tank straps would go (vertical straps). The indentations for the metal tanks straps make good places to grip the ratchet straps. I had to move them around some though as you have to have the tank to the passenger side practically all the way to the tire in order for the hoses to clear. There a several places to attach hooks underneath the Jeep. The 3rd (horizontal) strap I merely wrapped around the passenger side of the tank (top or bottom of the seam, I did top the first install, bottom second. Both worked and I did whichever was convenient at the time) and attached the hooks to anywhere on the driver side.
The tricky part was getting the tank to sit diagonally with the hose ends right at the oval hole and the passenger side nearly at the tire and touching the ground. I had both vertical straps shifted to the passenger side a little so the tank would hang in that spot without having to be held in place (though the hoses can pretty much hold it but will be harder to move if you go that route).
At this point, I ratcheted the horizontal strap slowly until the hoses were contacting the unibody or penetrated the oval hole if you have it lined up perfectly. I didn't have it lined up perfectly, so I would ratchet once, jamming the hoses into the unibody, and use their flexibility to bend them up into the hole. You cannot just ratchet horizontally at this point. I had to incrementally ratchet horizontally, then fix the hose ends, repeat until the ends were all the way through the unibody's oval hole (otherwise the hoses will dig into the top wall of the hole). But once they are through, it should go smoothly the rest of the way horizontally, though it will still take some effort. But when you get the hose ends through the hole you want to start ratcheting the vertical straps as you ratchet the horizontal strap so the tank will get level instead of diagonal.
As you do this, the passenger side of the tank will have to clear the leaf springs, then the "frame rail" of the unibody. I did have to move my vertical straps once each during this process, so a 4th strap will come in handy (though I only used three. Once I got it pinched vertically to hold it in place, I used the horizontal strap in a new vertical position then pulled one of the vertical straps off and used it in a new position for the other side of the tank). At this point I put the 2nd placement of the vertical straps where metal tank straps would go, simply because the indentations of the tank make for good holding places for the straps. But you will have to move them to get the tank straps on.
Getting the filler neck off the first time was kind of a bitch. Wear gloves. i cut myself on the rusty cover without. Getting the filler and return hoses back on the neck is kind of a pain, but at least you can access the hose clamps on that end.
Alternatively, I was considering never disconnecting the filler neck and dropping the tank slightly until the tank side hose clamps were sort of accessible. I didn't realize this until the second time I had to drop it, but I was already comfortable with the other way. The issue is the tang on the filler neck that slides into a strap. But I think you could slide the hoses and neck all the way down to the hole in the unibody if you can get the tang out of the strap. That may provide enough room at the tank to get to the hose clamps.
I tried to use a floor jack earlier, but the straps proved handier due to needing to get the tank diagonal. I would drain the tank, though not totally necessary. I had about a quarter tank and I didn't drain it.
Was that clear enough? let me know if you have any more questions.
