1991 3FE cutting out issues

[MTN HOME TLC]

I recently took my Cruiser to the mountains for a day out. It worked great on the way out but after several hours of driving it started to bog out when I would accelerate. The RPMs would drop to below 1000 and it would chug up to around 35 mph then repeat the bog out. What could be the cause of this problem. I got it home and let it sit for several hours and took it for a short spin and it was back to normal. Any help would be great.

[kodiak61]

I'm no mechanic, but my rig acted like that once and it was a dirty fuel filter.

Only thing that puzzles me about yours though is that it went back to normal...

[tim.korn.99]

Sounds exactly like my 91. It only does it on the drive home, after a few hours of wheeling.

I've replaced the fuel filter, and that didn't fix it. It's definitely something electronic.

Here's the weird part...

I can be driving along at 55, and it will start acting up (bogging, cutting out, very little power), and I can throw it in neutral, turn it off for a few seconds, then fire it back up and I'm good to go for about 5 more miles. Then it starts acting up again.

The first time it did it, it took me about 2hrs to drive 30 miles... then I figured out that turning it off and then back on fixed it for a while.

Anyone have any clues? Ignition coil maybe?

-Tim

[ncrockinfj]

what an odd problem my 91 only did that once ... but i was running of gas

[tim.korn.99]

Hmmm, now that I think about it, i guess it could be the fuel pump going out? But, would shutting the vehicle off for a couple seconds cause it to start working fine for a while?

-Tim

[jcj_78FJ40]

Try replacing the screen on the fuel pump. Sometimes it will get clogged up and collapse on itself. If you let it sit for a while then things settles and it will let up.

[MTN HOME TLC]

I can turn mine off and it will stop doing it for maybe 1 mile then right back to it????

[Red Beard]

Driving through any water? My 3FE did that when I didn't have 02 sensors in, and the connectors got wet.

[MTN HOME TLC]

no water

[lt1fire]

if it only did it once and hasnt done it again it could just be something as simple as bad gas

[ThePookieBear]

My old honda was doing this and I ended up needing to replace the distributor and all. I would do the neutral shut off deal too. Who knows.

[lt1fire]

Originally Posted by lt1fire

if it only did it once and hasnt done it again it could just be something as simple as bad gas

never mind I just saw that it has happened more than once.
I would find a buddy or fellow TLCA member in your area and start swapping on some of his things to see if it goes away. I had a problem with my camaro once and swapped parts from my friends vette untill his MAF solved the problem on mine and saved me mucho $$$$ on a mechanic finding the problem.

[hj60]

A failing fuel pump can cause the symptoms you describe.
If it's failing due to overheating, the few seconds of rest can allow it to cool enough to work for a little while longer.
They're fuel cooled normally. If you frequently run your tank to near "walk the :censored: home", it's not getting cooled anymore. Do this long enough, and it will go bad.
Buy/rent/borrow a fuel pressure gauge and test the pressure next time it happens.
Also, IIRC, the fuel pressure regulator can cause similar symptoms. Check that as well. I think it's vacuum controlled on the 3FE? A cracked or rotting vacuum hose might be causing it to dump pressure back to the tank.

[ktmracer01]

check your intake hoses. it is very common to find that the intake hose right at the intake manifold is torn between one of the ridges.

[CJF]

Originally Posted by jcj_78FJ40

Try replacing the screen on the fuel pump. Sometimes it will get clogged up and collapse on itself. If you let it sit for a while then things settles and it will let up.

Yup.

No guarantees of course, but this is quite likely the problem.

Curtis

[TX Cruiser]

Originally Posted by hj60

A failing fuel pump can cause the symptoms you describe. "Snip" If you frequently run your tank to near "walk the :censored: home", it's not getting cooled anymore. Do this long enough, and it will go bad.

My time is thin on the fuel pump. Time to keep turning left.

[jonheld]

Originally Posted by jcj_78FJ40

Try replacing the screen on the fuel pump. Sometimes it will get clogged up and collapse on itself. If you let it sit for a while then things settles and it will let up.

We have a winner!
The FP intake filter is a soft mesh. It will collapse on itself after an hour or so of driving. When you shut the motor off it will expand back into shape, but once the fuel in the tank is warm it will collapse on itself in a short time.
These filters should be replaced every 100K miles (just like the fan clutch). No one knows they exist and they'll swap in a new fuel pump with a new pre-filter and it'll solve the problem.

Spend a few extra sheckles and replace all the gaskets and cushions as they're most likely old and crusty.

[NJTaco]

I have a similar symptom with my 62 right now...and ordered a pre-filter for the tank, and a coil, along with a few other part$.

I have two questions, though...first, does the problem clear up if you drive in 3rd instead of drive? Mine does...also if I am going over 55 mph, it is greatly reduced in drive.

And second, is your fender-mounted blower operating? Mine isn't...

What I'm getting at is that you may be overheating your intake and fuel rail, like I am. I'll know tomorrow if I'm right, as I am hot wiring (fused) the blower for the ride to work.

I'm still going to change the pre-filter, though. It just seems like it should be done regardless.

Good luck...

[GAS-A-LOT!]

I had same problem, and did the fuel injection system cleaning at pep boys and no more issues....

[sseaman]

going back to the original post, i would check the air intake for cracks, since offroading it could move enough to tear and cause problems

[4xoddic]

Originally Posted by NJTaco

And second, is your fender-mounted blower operating? Mine isn't...

What I'm getting at is that you may be overheating your intake and fuel rail, like I am. I'll know tomorrow if I'm right, as I am hot wiring (fused) the blower for the ride to work.

How have you diagnosed the fan? I ask because after 19 years of owning an FJ62, I'd have to admit I've only caught that fan running very few times here in the heat of KS. Most of those times were after parking the FJ62 on a very hot day (100 F, etc.) & then it would kick on after a couple of minutes.

Have to admit I never had to change a fuel pump prefilter on either of our FJ62s. Don't believe it was even mentioned when the gas tank service bulletin replaced the OEM tank in the early 90s. Wouldn't hurt to have Toyota check your VIN to see if the tank replacement was carried out.

[NJTaco]

4xoddic,

I studied on the service manual a bit, and instead of removing the sender for a hot oil bath test, simply shorted the sender wire to ground, and the fan ran.

I ran to work this morning with the fan running, and in drive, with no problems. However, it was 20 degrees cooler this morning than it has been lately. So I consider this encouraging, but inconclusive. It should be up to a normal hot and humid by the time I get out of work tonight, and I'll test it the same way.

I've not had a 62 before, so I'm not sure what to expect of the fan. The FSM does not give a dignostic tree that I could find, just a schematic and component test procedures. There IS an "ignition hot" lead going to the relay, but I'm not sure that means the fan should run whenever the ignition is on.

More later...

Oh, if it matters, my fuel tank was replaced around 1992 or 94.

[CJF]

Originally Posted by NJTaco

4xoddic,

I studied on the service manual a bit, and instead of removing the sender for a hot oil bath test, simply shorted the sender wire to ground, and the fan ran.

I ran to work this morning with the fan running, and in drive, with no problems. However, it was 20 degrees cooler this morning than it has been lately. So I consider this encouraging, but inconclusive. It should be up to a normal hot and humid by the time I get out of work tonight, and I'll test it the same way.

I've not had a 62 before, so I'm not sure what to expect of the fan. The FSM does not give a dignostic tree that I could find, just a schematic and component test procedures. There IS an "ignition hot" lead going to the relay, but I'm not sure that means the fan should run whenever the ignition is on.

More later...

Oh, if it matters, my fuel tank was replaced around 1992 or 94.

Manifold cooling fan should only come on immediately after shutdown in reasonably warm to very hot weather.

Curtis

[NJTaco]

Originally Posted by CJF

Manifold cooling fan should only come on immediately after shutdown in reasonably warm to very hot weather.

Curtis

Thanks Curtis! (And others) It looks like I need to look elsewhere for a fix for my running problem. Time to change that tank filter, too.


Mtn Home TLC and Tim, I hope you guys have better luck troubleshooting your trucks than I am!

[jcj_78FJ40]

Originally Posted by jonheld

We have a winner!
The FP intake filter is a soft mesh. It will collapse on itself after an hour or so of driving. When you shut the motor off it will expand back into shape, but once the fuel in the tank is warm it will collapse on itself in a short time.
These filters should be replaced every 100K miles (just like the fan clutch). No one knows they exist and they'll swap in a new fuel pump with a new pre-filter and it'll solve the problem.

Spend a few extra sheckles and replace all the gaskets and cushions as they're most likely old and crusty.

That was the fix for the same problem I had for my 3FE 80. I believe I found this on one of your old posts.

[jcj_78FJ40]

Originally Posted by NJTaco

I have two questions, though...first, does the problem clear up if you drive in 3rd instead of drive? Mine does...also if I am going over 55 mph, it is greatly reduced in drive.


Good luck...

Also had this issue. The fix for me was cleaning the EGR valve and replacing the EGR modulator. I think that Autozone even carried the Denso one for around $35.

This was also from one of Jon Heald’s threads. I think he refers to the modulator as the “flying saucer” looking thing

[azzzuki]

Originally Posted by MTN HOME TLC

I recently took my Cruiser to the mountains for a day out. It worked great on the way out but after several hours of driving it started to bog out when I would accelerate. The RPMs would drop to below 1000 and it would chug up to around 35 mph then repeat the bog out. What could be the cause of this problem. I got it home and let it sit for several hours and took it for a short spin and it was back to normal. Any help would be great.

I 2nd the fule pump!

[upcruiser]

I'm surprised that no one has mentioned the EFI relay yet. Notorious on FJ80's and can cause similar symptoms.

[Marco7]

Originally Posted by upcruiser

I'm surprised that no one has mentioned the EFI relay yet. Notorious on FJ80's and can cause similar symptoms.

Notorious indeed! At least on the 91-92 models.

Be sure to replace the EFI relay with OEM Toyota, other aftermarket relays will not last long at all. I also upgraded the wires leading to the relay to a lower(beefier) guage wire.
From what I read in the past, the original wire was too narrow to carry the current in extreme heat situations. Haven't had any problems since, 3+ yrs, but this was a constant summer-time problem for me for several years.

[jonheld]

Originally Posted by upcruiser

I'm surprised that no one has mentioned the EFI relay yet. Notorious on FJ80's and can cause similar symptoms.

Please read post 1 and 7 in this thread. That is not the typical symptom of an EFI related problem. Fuel related issuse tend to be more of a ramp down/ramp up while EFI/spark related issues tend to be more like a switch off/on.

Not to say that it's impossible, just not likely given the description.