Fuel in Oil Problemo! Need help troubleshooting. (1 Viewer)

[Judh8smud]

Well, I'm back on the forum with more problems as per the usual.

As an update for those who have been helping me out here on mud, THE FJ40 IS RUNNING!

Here's a picture of her for the sake of having pictures...pretty ain't she? haha

SPECS: '76 2F Motor

THE SCOOP: So the problem is, as I was changing the oil, we found that there was a good bit of fuel mixed in it.

DIAGNOSIS: According to my research, there are quite a few things that can be causing this, i.e, flooding the carburetor so the carb is dumping fuel through the engine into the combustion chamber, a bad diaphragm on the fuel pump which can cause fuel to leak through the crankshaft, or bad compression and oil rings on the pistons.

I've begun to take apart my fuel pump to examine the diaphragm, but I haven't reached any conclusions on that possible problem quite yet.

But before I get too immersed in attempting to troubleshoot any of the scenarios described above, I wanted to run the problem by you all to see if any of you have experienced this before and see what you did to fix it!

All of your advice and information is appreciated!

 

[FishTacos]

I would guess bad diaphragm on the pump if I had to put money on it. Some pumps require a spacer between the block and the body of the pump and, when missing, the lever on the pump over actuates the diaphragm causing it to rupture

 

[FishTacos]

Pics of the pump?

 

[1911]

I would guess bad diaphragm on the pump

Me too; fuel pump is the most likely (and cheapest to replace) culprit.

 

[snaggletto]

Agree, replacing the fuel pump would be a good first move.

 

[brian]

if you're dumping enough fuel into the engine to get it past the rings....and you can't tell that it's running that poorly...cause it would be running pretty poorly....then maybe an old truck is not for you.

 

[Judh8smud]

Pics of the pump?

I appreciate your input! I'll get some pics of the pump on here asap.

 

[FishTacos]

if you're dumping enough fuel into the engine to get it past the rings....and you can't tell that it's running that poorly...cause it would be running pretty poorly....then maybe an old truck is not for you.

Spotting this morning are we?

 

[Judh8smud]

Pics of the pump?

Here's the pics I got today...

--------------------- Some close-ups of the Diaphragm and interior components ---------------------

Here is the location where the pump connects to the block and I found that the gasket was totally falling apart...

Right here you can see a bit of a tear in the diaphragm but it does not appear to go all the way through...?

 

[Tezmac]

This may be a bit anecdotal, but I tore down a good part of my engine after having my Cruiser for 8 years, and the PO had never installed the gasket between the pump and block. So just based on that, I'd be surprised if that was your culprit. Or maybe I was just lucky! The rest of your pump looks pretty much like mine did when I pulled it apart, less that small crack, and mine operates just fine. Maybe your problem lies somewhere else?

 

[Judh8smud]

This may be a bit anecdotal, but I tore down a good part of my engine after having my Cruiser for 8 years, and the PO had never installed the gasket between the pump and block. So just based on that, I'd be surprised if that was your culprit. Or maybe I was just lucky! The rest of your pump looks pretty much like mine did when I pulled it apart, less that small crack, and mine operates just fine. Maybe your problem lies somewhere else?

Yeah that's kinda what I'm thinking too because I don't believe there is any way fuel could be leaking through that gasket at the block. It seems the only point at which fuel can actually leak through is at the diaphragm, and in my case things are looking pretty good there aside from some minor wear. I have mixed feelings about the issue though, seeing that I cannot find a fuel pump rebuild kit anywhere, which won't be a problem if I end up not needing it, but then that means the problem is probably something a little more serious or expensive to fix...hopefully not.

 

[Judh8smud]

Something I should probably mention is the fact that when I have the engine running, it does run pretty rough, which I assume is expected as it has been sitting for over 2 years. But once I shut off the engine or it dies on me, I can hear what sounds like the trickling of fluid making it's way down the inside of the motor...

The sound seems to come from the top of the engine starting just beneath the valve cover and working it's way down. I'm not sure if that is at all normal but I don't like it and it could be fuel leaking through the intake valve via the carburetor...?

Any thoughts?

 

[FishTacos]

Carb problems. The OEM pump has a sight glass on the forward side of the carb body. The fuel level should be in the center of that sight glass. If it has a bad float or needle valve that could be the culprit too. HTH

 

[Tezmac]

Mine makes that same dripping sound. I've always assumed it's oil making its way back down. I'd definitely look at the carb next as it's the next easiest culprit to fix. Plus, hopefully all it costs is time!

 

[lcwizard]

Maybe by way of the PCV circuit. Are you drawing into the crankcase just below the carb?

 

[FishTacos]

Also, that pump doesn't need a spacer. The newer kyosan pumps often found on FJ60s and sometimes used as aftermarket replacement DO need a spacer. It isn't a gasket between the dry side of the pump and the block/cam/oil sump so if the pump gasket fails your oil gets all gassy and, obviously, that's not good.

 

[lockd80]

Not on a 2F but I have had a partially sunk carburetor float fill the crankcase on my tractor full of fuel. it was running ok but after letting it sit for a couple months it was a bomb waiting to go off.

 

[Judh8smud]

Also, that pump doesn't need a spacer. The newer kyosan pumps often found on FJ60s and sometimes used as aftermarket replacement DO need a spacer. It isn't a gasket between the dry side of the pump and the block/cam/oil sump so if the pump gasket fails your oil gets all gassy and, obviously, that's not good.

Ok so no spacer, but I do need to replace that gasket...right?

I think you're onto something in regards to the carb. I have rebuilt the carb, reset the float bowl level, and I believe I even replaced the needle valve, but that's not to say I didn't make any mistakes! I will definitely be looking at that next. Do you think the idle mix set screws could have anything to do with it? I don't know if I have those set just right either.

 

[Tezmac]

I'd replace the gasket, but that's just me. Mr. Toyoda put it there for a reason.

How was it running, or was it, before all this started? I wouldn't imagine that the screws could be so far off that you'd be dumping that much fuel into the engine. But then again, I'm not the expert that some of the guys on here are.

It doesn't take much effort to get the screws adjusted correctly using the lean-drop method and a timing light. But if you're having other issues, doing this could prove problematic. I'd mark where the screws are currently dialed in before messing with them, just so you have a reference point to jump back to.

Given that, it takes even less effort just to clean up the fuel window and take a peek to see if your carb overfills. It's also minimal effort to pull the hose that runs between the PCV valve and the carb to see if you're pushing gas backward through the crankcase.

 

[FishTacos]

Ok so no spacer, but I do need to replace that gasket...right?

Yes. Replace the gasket. Very inexpensive peace of mind.