The banjo bolts usually just have a copper gasket or a copper gasket with a small rubber inner liner. I’ve never run a pressure gage into the car with copper or any line so can’t say on that matter
Loss of Power at 2,300+ RPM - '86 FJ60 with 3FE/H55f (1 Viewer)
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4Cruisers
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I have a small leak at the threads of the LCE custom banjo bolt, not at the cold start injector, but at the end where the gauge fitting threads in. After doing some research there appears to be at least three options for gasoline-resistant thread sealants - Rectorseal No.5, Gasoila, and Permatex 2 Form-A-Gasket sealant. The Ace Hardware in Santa Fe has the Rectorseal No. 5 in stock, but it's a 1-hour drive one way. My local O'Reilly auto parts can get the Gasoila by tomorrow morning, and I can buy 1/8-inch copper tubing there by the foot. But before I left for town, I found a new, unopened tube of Permatex 2 in the garage. I'm heading to O'Reilly now to buy some tubing.
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4Cruisers
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I finished installing the LCE fuel pressure gauge kit (no leaks), including a 5-foot length of copper tubing to temporarily mount the gauge to the side view mirror. I ran through the FSM checks. Everything checks out, with pressures being near the high end of the range under all test conditions. After shutting off the engine the fuel pressure was still 41 psi after 5 minutes (FSM indicates it should stay above 21 psi for at least 5 minutes), and it's still at 41 psi 30 minutes later.
I'll be taking it out for a test drive with the gauge connected to see what the fuel pressure reads when it starts acting up at ~2,300 to 2,400 rpm, in different gears. What should I be looking for in terms of pressure, the same 36 psi at idle with the FPR vacuum hose attached?
I'll be taking it out for a test drive with the gauge connected to see what the fuel pressure reads when it starts acting up at ~2,300 to 2,400 rpm, in different gears. What should I be looking for in terms of pressure, the same 36 psi at idle with the FPR vacuum hose attached?
4Cruisers
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I just got back from a test drive - here's what I found. When accelerating up through ~2,200 rpm, in either 2nd, 3rd, or 4th gear, my fuel pressure drops down to between 16 and 20 psi, which seems very low to me. When I back off the throttle and the engine drops down below ~2,000 rpm, the fuel pressure's back up in the low-mid 30s psi range. Is that normal, or is it a bad FPR? Or???
The FPR's goal is to maintain a constant pressure across the injectors. Since one side of the injectors feels manifold pressure that's constantly changing, the FPR has to vary the fuel pressure to keep the pressure across the constant. At idle and while coasting, there is a very high vacuum in the manifold (low pressure), so the FPR will decrease fuel pressure. At high throttle, the manifold vacuum is low (high pressure) so the FPR will increase pressure.
Generally you should see a 5-8 PSI increase going from idle to full throttle. If you are dropping fuel pressure as RPM increases under heavy throttle, this is indicative of a fuel flow issue.
While I won't completely rule the FPR out yet - the fact that it appears to regulate at idle and engine off seems to indicate that it is functioning properly. You said you just installed a new filter, so we can rule that out.
There are four remaining possibilities :
- Plugged fuel lines
- Plugged fuel pump sock
- Failing fuel pump
- Poor fuel pump ground/power connection causing pump to run slowly.
I'd probably start by checking #4. There's a little cover under the rear carpet that allows you to access the fuel gauge sending unit. But you should also be able to get a hold of the fuel pump plug connection through that cover as well.
Generally you should see a 5-8 PSI increase going from idle to full throttle. If you are dropping fuel pressure as RPM increases under heavy throttle, this is indicative of a fuel flow issue.
While I won't completely rule the FPR out yet - the fact that it appears to regulate at idle and engine off seems to indicate that it is functioning properly. You said you just installed a new filter, so we can rule that out.
There are four remaining possibilities :
- Plugged fuel lines
- Plugged fuel pump sock
- Failing fuel pump
- Poor fuel pump ground/power connection causing pump to run slowly.
I'd probably start by checking #4. There's a little cover under the rear carpet that allows you to access the fuel gauge sending unit. But you should also be able to get a hold of the fuel pump plug connection through that cover as well.
4Cruisers
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- #46
#1 Fuel lines were cleaned and tested with the build about four years ago - empty tank inspected at the same time - fuel drained from tank this week was clean with no debris - new OEM fuel filter installed earlier this week - will check the lines again for blockage
#2 and #3 Above, plus new OEM sock installed with new OEM pump four years ago - only 4,209 miles since the build, and about 1,800 of those miles were while the vehicle was being tow-dollied to Colorado on two occasions (with driveshaft installed and transfer case in neutral) - may have to drop the tank and check both of those
#4 Will definitely check that out
Thanks for the reply.
I would check voltages while the pump is on before going through all of that.
I can tell you that if I were going to go through the hassle of disconnecting all of those lines, connections and drop the tank - It'd be getting a new OEM Denso pump installed.
I can tell you that if I were going to go through the hassle of disconnecting all of those lines, connections and drop the tank - It'd be getting a new OEM Denso pump installed.
Did you happen to replace the fuel pulsation dampener as well?
I’m just trying to help with “or” part.
I don’t know if it being bad would give you the loss of power, but it’s another part in the fuel delivery “train”.
I know you’ll get it sorted out!
This happened to me a couple times, first time the fuel pump ingested some crud from the tank, second time I found the inside of the distributor completely corroded because I had not plumbed the purge on the cap. As to fuel pressure, I have seen this in the Toyota EFI training:
When on the throttle, your manifold pressure is higher so I would expect the fuel pressure to go up to maintain the differential as @Lead Head stated. I looked through the TCCS literature I had and didn't find anything pointing to something happening at or near 2400 rpm. The fuel injection timing is largely dependent on rpm and air flow with some minor adjustment for temperature, throttle position and voltage. No emissions stuff changing state at 2400 rpm.
This is puzzling. The throttle would have to be more open to maintain power at the lower rpm. And since power isn't really changing, fuel and air would not change.
When you checked your TPS, did you connect your analog VOM between VTA and E2 then slowly open the throttle looking for any swings indicating a bad spot on the potentiometer? If you run at that spot a lot, it could develop a bad spot there.
Good luck with this, these can be aggravating.
When on the throttle, your manifold pressure is higher so I would expect the fuel pressure to go up to maintain the differential as @Lead Head stated. I looked through the TCCS literature I had and didn't find anything pointing to something happening at or near 2400 rpm. The fuel injection timing is largely dependent on rpm and air flow with some minor adjustment for temperature, throttle position and voltage. No emissions stuff changing state at 2400 rpm.
This is puzzling. The throttle would have to be more open to maintain power at the lower rpm. And since power isn't really changing, fuel and air would not change.
When you checked your TPS, did you connect your analog VOM between VTA and E2 then slowly open the throttle looking for any swings indicating a bad spot on the potentiometer? If you run at that spot a lot, it could develop a bad spot there.
Good luck with this, these can be aggravating.
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I have the fuel supply line disconnected at the tank and at the fuel filter, after coffee I was going to go out and blow compressed air through that section of line to make sure there are no obstructions. Then I was going to remove the cover over the fuel level sender and find the wiring connector to the fuel pump. I'll pull the terminals from the harness-side connector and replace them with new crimped terminals that have an external pigtail out the back of the connector. That way I can monitor the voltage to the pump from inside the vehicle, with leads plugged into the pigtail connector terminals.
I didn't do that, but the TPS was like new when I installed it during my build, and I had it adjusted exactly to FSM specs. As I mentioned before, the vehicle has only been driven about 3,000 miles in the four years since I finished my build. But I'll do those extra measurements this afternoon.
Also, the ground for the fuel pump and fuel sending unit is actually underneath the Land Cruiser. If you look where the wire goes into the tailgate for the license plate lights, follow it underneath the vehicle, and then look right where it pokes through the body, you will see a ring terminal. That ring terminal is the fuel pump ground.
Forgot to mention, check the engine harness ground on the engine.
And sometimes the O2 sensor wires/plugs melt down
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Well, I think I found the issue. Yesterday I received my latest Toyota parts order, which included a new fuel pump filter sock and the short section of fuel hose from the fuel pump outlet to the fuel outlet tube. This morning I dropped the fuel tank and cleaned the dirt and dust off the top. I removed the fuel pump assembly and did an inspection. The filter sock wasn't plugged at all, and the fuel hose and clamps were in good shape. The wiring and connections are like-new, so that's not the problem. However, when I looked at the end of the outlet tube it was blocked, it's a wonder I could even get the 3FE to start and run. Looks bad, doesn't it?
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Well, the raw power of the 3FE (teamed up with the H55f) is back! Everything's back together except the fuel line shield, sway bar brackets, and spare tire carrier. I drove it around the neighborhood, including up some fairly steep hills, and it's running strong again, with crisp acceleration through all rpm ranges. Tomorrow morning I'll undo the temporary fuel pressure gauge at the cold start injector and reinstall the rest of the remaining parts. Then it'll be ready to take out to the mountains above town and the pueblo ruins and cliff dwellings north of town.
I did all the major work today during daylight hours out on the driveway, including dropping the tank, replacing parts, flushing out the tank and fuel lines, reinstalling the fuel tank, and reconnecting all the fuel lines. Not bad for an old guy pushing 68 working alone.
I did all the major work today during daylight hours out on the driveway, including dropping the tank, replacing parts, flushing out the tank and fuel lines, reinstalling the fuel tank, and reconnecting all the fuel lines. Not bad for an old guy pushing 68 working alone.
Long live the 3FE.
That’s awesome!!! Did you figure what the material was clogging the line? Tank liner? Rust? Looks like metal filings…
