3FE acting up (1 Viewer)

[ylexot]

I have a bit of a mystery with my engine that has left both my mechanic and I scratching our head.

Here's the story:
Generally my Cruiser runs well. It's getting a little tired, but runs incredibly well, especially for the mileage. It is a 1989 FJ62 with ~330k is all original as near as we can tell. However, it has had some stalling problems that appear to be related to moisture.

The NW in winter is a pretty wet place, but it has only sputtered and stalled when I am, or have recently been, running at highway speeds on a water logged freeway where there is that ultra fine mist kicked up by a mess of cars on a wet freeway.

The stalling feels very much like a fuel problem. The first time it happened I changed the fuel filter thinking that it was just overdue. That wasn't it. We've checked the fuel pressure and it checks out well within spec. Good compression. No identifiable vacuum leaks. Even though it doesn't feel like an ignition problem, we also double checked the distributor for moisture, and it was dry.

Any ideas?

 

[RockDoc]

Does it throw any codes? The wiring for the fuel pump (towards the back) has given others trouble....

 

[szester]

maybe the water is causing something to short out and restart. I dont know how many computers it has but maybe check for bare wire

 

[ylexot]

It occasionally gives a code for the O2 sensor, but that's because it isn't hooked up. However, the 'dummy light' turns on very rarely and hasn't come on when the engine sputtered and doesn't seem to correlate to the above mentioned activity.

Wiring on the fuel pump, eh. Haven't looked into that, but sounds like a feasible fault. What kind of problems are likely down there? Anything specific I should look for?

 

[euclid]

Check the hose between the air cleaner all the way to the throttle body for cracks or openings.

How old are the plug wires? Moisture in the air can make a short show up. I replace mine as part of a major tune up. Keep the old ones in the truck for a spare.

Are you positive it relates to moisture?

Put a plastic bag over the distributer. With the motor running start spraying different areas of the engine bay till it runs rough.

 

[overhanger]

Do you have any rust holes in the rear quarter panels? Lots of wiring there in the cubby holes they create.

 

[ylexot]

Check the hose between the air cleaner all the way to the throttle body for cracks or openings.

How old are the plug wires? Moisture in the air can make a short show up. I replace mine as part of a major tune up. Keep the old ones in the truck for a spare.

Are you positive it relates to moisture?

Put a plastic bag over the distributer. With the motor running start spraying different areas of the engine bay till it runs rough.

Good thoughts, Euclid. I replaced the tube running between the air cleaner and throttle body and gave the throttle body a good cleaning this summer. I also did a tune up this summer, including all Toyota plugs, wires, dist and rotor.

I'm not 100% sure it is related to moisture. I have had several instances of stalling or near stalling and it has only been on days like I described. My mechanic and I drove around for a while last night in a light rain and no mist and were not able to replicate the problem. Fine mist could be a false correlation, but it matches so far.

 

[euclid]

Fuel Pressure Regulator?

Did it start right after the tuneup? If so, I'd wonder about the new plug wires.

Is the timing dead on? Are the valves nice and quiet? Thinking out loud...

 

[ylexot]

No real rust on my rig. quarter panels are dry.

Fuel pressure regulator: My rig isn't quite acting like that, although I can definitely relate to crappy 8-10mpg "economy" May be worth a check. If it gets me a 50% boost in fuel efficiency, that part would pay itself off pretty quickly.

 

[ylexot]

maybe the water is causing something to short out and restart. I dont know how many computers it has but maybe check for bare wire

This is kind of what we're thinking. Some kind of water induced short, perhaps even at the computer. While poking around last night, we did see some signs of moisture getting close to the ECU in the glove box area. Going to pull the glove box and keep an eye on that, just in general.

Are there any specific thoughts on wires or connections to check? We've looked at all the grounds and they seem fine, except for one that was found flying. We looked at another 62 to see where it was supposed to connect, but that engine was running fine with that lead clipped off at the firewall.

 

[smtyblt]

Two things that cause this condition are the ignitor going bad. And a worn out fuel pump.

Also you say the 02 is not hooked up. do you have it dangling in the air or just not plugged in.

 

[ylexot]

What do you mean by "ignitor"? The coil?

Yes, the O2 sensor is disconnected. I had a little device that pretended to be the O2 sensor by providing a 0V to 1V signal in it's place. The batteries on that device are dead, 0V, and have been for a couple months. I just haven't bothered to reconnect the O2 sensor. Definitely a suspect item, but seems unlikely to be the issue. A bad fuel supply, for one reason or another, seems to be the hitch.

Will be inspecting fuel pump wiring and trying out a spare FPR as soon as friend can put his hands on it. But by all means keep the ideas coming.

 

[Bryan062087]

Don't really have any new suggestions on how to fix the issue. Only input I have is that it sounds like it could be your distributor/and or cap getting wet. Mine does this really easily as I forgot to put on the o-ring after putting no a new dist cap. Any kind moisture near the distributor, it starts sputtering etc..

But I'm just curious.. What kind of shape the engine is in with that many miles? Do you burn any oil? Hows the compression? Whats the history on the engine/truck? What oil are you running? That's an impressive amount of miles you've got on it. How many water pumps etc have you gone through?

 

[ylexot]

This Cruiser is pretty new to me. I bought it early this summer after I sold my BJ. (At this point I am definitely considering another diesel swap, but I can't swing the dough right now.)

As for oil, I don't think it is burning any. It is leaking the typical several drops a day at the rear main seal, so it is impossible to tell from volume if any is burning from volume. The oil was changed about 300 miles ago, and is still very clean for what that's worth.

Don't know about water pumps. It does kick off a bit of steam when the engine is cold. The exhaust turns normal after it gets warm and while it is puffing white it doesn't smell sick sweet like antifreeze. I don't know where the water is coming from on start-up. Another mystery to stir the pot.

330k miles isn't common, but certainly not unheard of. I just wish I had driven most of them.

 

[Bryan062087]

330k miles isn't common, but certainly not unheard of. I just wish I had driven most of them.

Yep, I've had one with 300k and one with 250k, no engine work.

I don't think that steam is anything to worry about, sounds like normal condensation to me.

Back to the original topic..

 

[Aseif007]

So right after you have been cruising at highway speeds and exit the highway and come down to idle it sputters for a second and somtimes pulls out of it, and sometimes stalls? And will fire right back up afterwards? If this is the case I had a 3FE with no rebuilds that I put 296,000 miles on which did that exact thing. When I tore down the motor the EGR tube that goes into the intake manifold was gummed up to pin hole size and my theory was that since I thought the EGR only opens up at highway speeds or cruising speeds and since it was so dirty that it was getting stuck open and sometimes would close and sometimes not after a highway drive. I rebuilt the motor and replaced the EGR and it hasn't happened since. If I had replaced the EGR before I rebuilt the motor then I could say for sure it was the EGR. Maybe look at the EGR to see how gummed up it is?

 

[askeyey]

Some of the symptom could be related to moisture in the fuel system. Do you run Dry Gas or Heet in the gas tank with every fill up? It's been a live saver for me on all my older trucks over the years in upstate NY. I can tell a noticable differece between a tank with dry gas and tank without in my truck.

 

[ylexot]

quick update... my wife has kept me too busy in the daylight to even crack the hood on my cruiser. We are now looking for a new house: a laborious task that will take away time from working on my machine , but may translate into a better garage.

I will definitely take a peek at the EGR. I have no idea when it was last checked/replaced. I have certainly ignored it so far. Thanks.

My first thought was that there was water in the fuel and water from the air intake was diluting the fuel to the point of stalling. I haven't been smart enough to put heet in the tank. It won't be the first time I've ignored the simple solution in order to complicate my life. I hope it works.

 

[spdsmoky]

I had the same problem. It is your ignitor.

 

[spdsmoky]

The ignitor is attached to your coil (sits on top of it).