1970 FJ40 - Clogged Fuel Pickup?

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idontknowanything

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Sorry in advance for the long post. I am a novice and don't know what information might be important, so I'm just giving as much detail as I can.

I have a 1970 FJ40 with a 2F swap. Rebuilt engine has about 6,000 miles running on an Aisan carb. I got the car about a year ago and haven't had any serious issues up until now.

I was driving a few weeks ago and had a severe loss of power. The issue seemed to start after going up a slight incline hill (5-10 degrees for maybe 300 feet). I switched from 3rd to 2nd gear, and was able to get enough power to get where I was going.

I drove it several times over the next few weeks (short distances, ~1 mile) without issue.

A few weeks later the same issue happened. At the literal exact same place where it happened before (a short, brief incline). This time the loss of power was more severe. And it eventually stalled. I was again able to start it back up and eventually get where I was going.

It is quite cold here (as low as 20F), I tried putting HEET in the tank, and while the issue was occurring, took the gas cap off to check for vacuum issues (no whooshing, venting had no effect).

The next day, I tried to drive about two miles. Again I started experiencing a loss of power after going up a slight incline. I was able to barely limp where I was going, it stalled out several times along the way.

On the way home that same evening, I only made it about a block before the car stalled out and wouldn't move at all. I had to leave it over night.

Unfortunately I also left the lights on during this period... When I came back to next morning, the lights were still on, but I didn't have enough juice to start it.

I jumped it I was able to limp it back like 500 feet to a place where I was able to work on it. Still experiencing the same issue where it would seem to gradually die out when ever I put it in gear. It always idled fine during this period.

It seemed like a fuel delivery issue to me. So I replaced the fuel filters and the electric fuel pump. During this time it was sitting for around 4 days.

With a new fuel filter and pump, it started back up (again, had to jump it). I let it idle for 45 minutes or so to give the battery some charge.

I was able to drive about a mile or 2, before the same issue happened again. I was able to get it started back up and limp it home (had to jump it again).

It is now back on my garage on a trickle charger and I am trying to decide what to do next.

I'm leaning towards a blockage in the tank itself. Maybe a clogged fuel pickup sock/debris in the tank?

Any thoughts would be greatly appreciated!
 
When it stalled did you happen to look at the fuel level in the carbs site window?
 
Have you checked for a second hidden fuel filter. Forty years ago has an issue with a ford van that would stall on inclines. Found a fuel filter a PO had installed. Also the FJ40 tanks have a drain in the bottom would not add more fuel and run until it low. Drain the tank and see what you find. The pick up is on the driver's side of the tank. With the fuel low enough can remove the fitting and blow compressed air. There is no sock on the end in the tank. Because it happens regularly when under heavier low like climbing thinking there is a blockage. An electric fuel pump should be able to keep carburetor float level even because it does rely on engine RPM for the delivery rate like a stock manual fuel pump.
 
Hi Welcome. I use gas tank heat in the winter too. Warm days with cold nights will condense water right out of the air in your gas tank (keep full minimizes this) and the stations tank. The little yellow bottle will only suck up so much water. The paper element in your filter will not pass fuel if wet with water, I swap mine out and let them dry out in the sun, and they are good again.

I run a diode electric fuel pump. Switch on key, listen for clicking to slow down, step on gas pedal - pull the choke on - release the gas pedal - engage the starter - let idle for a while - push in choke as it loads up.

I made fuel transfer pumps using the same electric unit. Fused, switched, filter, 10' power cord that will plug into the cig lighter or clamp on on the battery. 5' draw 20' delivery hose (can be reversed for fuel harvesting). Will also go diesel, Was like $50 years ago.

You can hook it into your system at the carb and use a 5 gallon can of fresh gas, thus bypassing your system and see if your rig runs.

You could have trash in your tank, lots of water, plugged filter, an air leak in a hose/fitting that prevents the fuel pump from sucking up fuel to pump to he carb.

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I had a similar problem in my FJ60. After much parts replacements and cleaning fuel lines it turned out there were pieces of paper in the tank that would periodically plug the pick up.
 
OP posted then never showed back up … first and only post a week ago

1) he fixed it and didn’t report back
2) he found it was something simple and embarrassed to say what
3) he forgot his PW for Mud
4) sold the truck out of frustration
5) immigration got him and brought him back to Nogero :meh:
 
Hi! Sorry for the delay! I got sick and didn't have time to work on it until recently.

I am back with an update!

I laid down under the vehicle and removed the (metal) prefilter once again. When I pulled the hose, in addition to the gasoline that went into my eyeball, there were a bunch of black chunks of something that came out as well.

I replaced it with a clear filter and waited for the issue to happen again. I have attached a photo (First image) of that clear filter after running for about 2 miles. So my guess is this is what was clogging the filter and preventing fuel from making it to the engine.

So there is probably something in or around my gas tank that is the root of the issue. As a fix, I figured I probably shouldn't be running such a fine grained prefilter.

I picked up one of these and installed it Clear View Fuel Filter for 3/8” i.d. Hose - https://www.edelbrock.com/clear-view-fuel-filter-3-8-inch-id-hose-8748.html.

In doing so, a new and more serious issue sprung up. I do not know if it is related.

I will start the vehicle. After about 1-2 minutes, even while just idling, a fuse will blow. The fuse in question is the circled area in Img #3.

The only thing I messed with recently was replacing the fuel pump. There is an inline fuse (5A) running to the fuel pump. The fuse that is blowing is 30A. The 5A inline fuse to the pump is fine.

This started happening only after I switched out the prefilter.

When that 30A fuse blows, the power to the fuel pump dies, when the power to fuel pump dies, the engine dies. So now I am stranded.

I don't even know where to start with trying to find the source of the fuse blowing.

Going to do some more research. Any thoughts are appreciated!

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Disconnect the negative battery cable. Get like a 30 cal wire bore brush and clean the fuse contacts clips on the box. Also pull the whole unit and clean the contacts on the back. Check all wire terminals at the crimp - corrosion can crawl under the insulation and add tons of resistance that can blow fuses.

Trash in the gas tank is common. Comes from the gas station, transport trucks... and your own tank rusting or liner brake down. Keep gas tank full - warm days cold night will condense water right out of the air into your tank. Gas drier help. Empty the gas tank, remove it and shake out the crap. You could do a alcohol proof liner treatment if the tank looks bad inside.

Electric fuel pumps go bad. I run the $10 ones that last about 10 years. This is my fuel transfer device. Switched, fused, filtered, 10' power lead to cig lighter or battery, 5' draft 20' delivery (can be reversed for fuel harvesting) was like $50 to build several years ago.
 
Thanks
charliemeyer007 said:
Disconnect the negative battery cable. Get like a 30 cal wire bore brush and clean the fuse contacts clips on the box. Also pull the whole unit and clean the contacts on the back. Check all wire terminals at the crimp - corrosion can crawl under the insulation and add tons of resistance that can blow fuses.

Trash in the gas tank is common. Comes from the gas station, transport trucks... and your own tank rusting or liner brake down. Keep gas tank full - warm days cold night will condense water right out of the air into your tank. Gas drier help. Empty the gas tank, remove it and shake out the crap. You could do a alcohol proof liner treatment if the tank looks bad inside.

Electric fuel pumps go bad. I run the $10 ones that last about 10 years. This is my fuel transfer device. Switched, fused, filtered, 10' power lead to cig lighter or battery, 5' draft 20' delivery (can be reversed for fuel harvesting) was like $50 to build several years ago.
Click to expand...
Thanks for the info. I am going to try that now. If the issue was at the fuse box, would you still expect the fuel pump to be working? When just the battery is engaged (vehicle not running), the pump runs fine, no fuses blow.

It is only once the vehicle starts running that the fuse heats up and blows.

I traced the white and red wire from that circuit. It runs back to the Regulator. Think that could have anything to do with it? It seems like the fuse only blows when the alternator is running, and that wire leading to the regulator seems like it could be relevant.

Thanks!
 
I would expect the fuel pump to draw most current with the ignition on but engine not running. But with mystery wiring and parts who knows
 
charliemeyer007 said:
I would expect the fuel pump to draw most current with the ignition on but engine not running. But with mystery wiring and parts who knows
Click to expand...

Okay I unplugged the regulator. This prevents the fuel pump from running (engine off but key engaged). It ran for a while with the fuel in the bowl before dying (no blown fuse). I reconnected the regulator and now it is running, and the fuse is no longer blowing.

I don't know that I've learned anything here, but hopefully it is enough to get me home.
 
I lost a mechanical fuel out in the desert @ like 105 degrees in the shade. I managed to drive home with an IV bottle of fuel tied to the roof (nice to have extra fuel hose, gas, cordage) I have also driven rigs home with my aux transfer pump - because it bypass bad gas fuel tanks and pumps for carbed units.
 
Another update, in case anyone is reading this in the future.

Fuse is no longer blowing. But I'm having the same problem I started with. Which I now assume is something to do with a clog originating in the fuel tank.
 
I would empty the tank with my fuel transfer pump. Pull the tank out. Pull the sender. Get a couple of hand fulls of clean really sharp chip coat gravel. Put in tank, duct tape opening closed. Shake like hell for a long time or set in load bead of pick up truck and go for a long drive on a really rough road - rotate tank to do all sides. Shake out gravel and crud. Blow out with air the lines and tank. Do an alcohol proof gas tank liner treatment to prevent rust. Put in sender, install the tank. Use some gas drier to help keep water out of tank.
 
I didn’t read most of the thread but, when it occurs shut the engine off immediately and safely, then look at fuel level in sight glass on carb. That will tell you if under or over fueling. If you don’t see a line of fuel in the glass, crack the 14mm nut loose and it should drain fuel (a towel is good here). If the fuel line appears, it’s overfueling and causing stumbling.

If there’s no line and barely fuel, you have a fuel pump/pickup/line issue.
 
It's easy to pull the sending unit in the gas tank and use a flashlight and look inside the tank for rust or something. It seems the bits in the filter are black. How old are the rubber hose? Then there are the metal lines.
 
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