Power woes 1992 FJ80 (1 Viewer)

[DawtSpot]

I'd love to be able to take my 1992 FJ80 up to the mountains, but it just doesn't have the power. I've been trying to find info on a supercharger, but everything posted seems to be for FJZ80's and not FJ80's. I'm also wondering if I could just put in some sort of nitrous or meth injection instead since I'm really just trying to boost the power for a couple minutes to make it past some of the steep passes...

 

[bhsdriller]

That's the downside with the earlier years get used to it

Nitrous sounds cool, try it and let us know

 

[ColoradoBoy]

Not to be a jerk, but maybe the motor just needs some baseline love? I take my 91 up to 12k feet with no issues....

 

[leonard_nemoy]

Not to be a jerk, but maybe the motor just needs some baseline love? I take my 91 up to 12k feet with no issues....

No issues at 12k feet with your 91.......... You must not be driving on anything very steep.

The 3fe is pretty gutless, it can certainly get up most mtn grades but some roads can just be to steep for the old 3fe.

There is a paved canyon rd close to me that goes up to about 10,000ft with a 13% grade. It is the steepest paved road in Utah. For reference the steepest part of the I80 Eisenhower pass in Colorado is only 6%

Driving U-143 will put your brakes to the test<BR> With 13% grade, it's steepest paved road in the state - https://www.deseret.com/platform/amp/2000/5/26/19508864/driving-u-143-will-put-your-brakes-to-the-test-br-with-13-grade-it-s-steepest-paved-road-in-the-stat


My 91 could only make it up this 13% grade in 1st gear. It was almost to dangerous to go that slow because of all the subaru's and domestic trucks that could go so much faster. I just started using low range for the steep stretch and I would still end up in 2nd gear by the end of that grade.

My 91 could only handle highway 14 with a max grade of 10% in 2nd gear. And I know the 3fe in my 91 did not need a tune up.


To the OP, consider using low range or do a motor swap if you are not happy with the performance in these kinds of scenarios.

 

[DawtSpot]

No issues at 12k feet with your 91.......... You must not be driving on anything very steep.

The 3fe is pretty gutless, it can certainly get up most mtn grades but some roads can just be to steep for the old 3fe.

There is a paved canyon rd close to me that goes up to about 10,000ft with a 13% grade. It is the steepest paved road in Utah. For reference the steepest part of the I80 Eisenhower pass in Colorado is only 6%

Driving U-143 will put your brakes to the test<BR> With 13% grade, it's steepest paved road in the state - https://www.deseret.com/platform/amp/2000/5/26/19508864/driving-u-143-will-put-your-brakes-to-the-test-br-with-13-grade-it-s-steepest-paved-road-in-the-stat


My 91 could only make it up this 13% grade in 1st gear. It was almost to dangerous to go that slow because of all the subaru's and domestic trucks that could go so much faster. I just started using low range for the steep stretch and I would still end up in 2nd gear by the end of that grade.

My 91 could only handle highway 14 with a max grade of 10% in 2nd gear. And I know the 3fe in my 91 did not need a tune up.


To the OP, consider using low range or do a motor swap if you are not happy with the performance in these kinds of scenarios.

Thanks for the response. Yea, it's the steep grade past Georgetown on I-70 that gets me. I can make it to winter park, but past Georgetown is just too steep. I've tried 2nd gear, but at best you are going 50mph, and with semi's going 75 it's just not worth it. My compression is amazing for over 200k, I put in new spark plugs and wires, replaced the entire exhaust including the cats, replaced all the filters, and ran solvents through the oil and fuel lines. I'm running on stock wheels. My injectors are clean. There's really not much more I can do to the engine. I have not advanced the timing... truth is I love this thing. I don't really want to swap the engine. I have swapped an engine in the past, and have lots of experience with 300sd turbo diesel mercedes, so the thought crossed my mind, but this is currently my daily driver, and my last engine swap took me about 7 months to finish.

 

[jonheld]

General Tech - 3FE Tune Up Info

3FE Tune Up Info

forum.ih8mud.com

 

[jonheld]

As a point of reference, I've driven both my old 91 and my "new" 97 up and over I70 several times pulling a small trailer. I was down in 2nd gear in the right lane in both trucks. So while the 97 is somewhat less gutless, it is still VERY gutless by comparison to vehicles made in this century.

 

[Jason Andrews]

Been there.

My best advice is to downshift way earlier than you think you should to help maintain momentum. Once your rpms drop too low even going to 2nd gear doesn't help. I used to drive mine in 3rd gear pretty much all the time unless I was above 60mph on flat ground.
I remember going up Berthoud pass on the way to Winter Park and Steamboat with my 3FE. After 30 seconds or a minute or so of revving at a high rpm the engine would actually change audible tone and strangely become quieter. It's almost like it found its groove and liked it. Never understood what caused it but it sounded better.

IIRC I used to hold mine at 3800-4000rpm and it didn't miss a beat. If you have done the PM, just drive it like you are trying to kill it. Bet you can't.

 

[ColoradoBoy]

Been there.

My best advice is to downshift way earlier than you think you should to help maintain momentum. Once your rpms drop too low even going to 2nd gear doesn't help. I used to drive mine in 3rd gear pretty much all the time unless I was above 60mph on flat ground.
I remember going up Berthoud pass on the way to Winter Park and Steamboat with my 3FE. After 30 seconds or a minute or so of revving at a high rpm the engine would actually change audible tone and strangely become quieter. It's almost like it found its groove and liked it. Never understood what caused it but it sounded better.

IIRC I used to hold mine at 3800-4000rpm and it didn't miss a beat. If you have done the PM, just drive it like you are trying to kill it. Bet you can't.

Well said. This mirrors how I have found that these rigs operate. They have to be strategically driven, not passively like the new cars now.

 

[tacocat]

I'm also wondering if I could just put in some sort of nitrous or meth injection

That’s a dangerous road. First your teeth fall out. Your camping trips start to get longer and longer.....

What size tires do you have? You do have a few non engine related options like a manual tranny swap H55F (I think) and a gear ratio change.

@leonard_nemoy that’s some damn good science right there. You have earned your blue shirt for today.

 

[White Stripe]

You could install a 2f shortblock with your 3fe head and a delta reground camshaft. That would give some more power. V8 swap is really what the truck needs.

 

[DawtSpot]

Been there.

My best advice is to downshift way earlier than you think you should to help maintain momentum. Once your rpms drop too low even going to 2nd gear doesn't help. I used to drive mine in 3rd gear pretty much all the time unless I was above 60mph on flat ground.
I remember going up Berthoud pass on the way to Winter Park and Steamboat with my 3FE. After 30 seconds or a minute or so of revving at a high rpm the engine would actually change audible tone and strangely become quieter. It's almost like it found its groove and liked it. Never understood what caused it but it sounded better.

IIRC I used to hold mine at 3800-4000rpm and it didn't miss a beat. If you have done the PM, just drive it like you are trying to kill it. Bet you can't.

lol, I have to admit I have been driving it a little more cautiously than I perhaps should. Thanks for the advice on downshifting earlier. If I get up the nerve, I'll try it again, with that RPM range in mind. Thanks!

 

[lt1fire]

While the 3fe is gutless I never really remember having issues with maintaining hwy speed. Drove in the mountains in CA all the time. People did say my 3fe drove better than theirs though.
I had 37's and stock gears on mine for a while... went up to 4.88s when I got the 39s.
When I first got the rig in 06 I baselined it completely, adjusted valves, and everything.

You will be going through a lot of nitrous if you are using it in that way.

Really you can do a camshaft and have the head redone and shaved to increase the CR. I think Mark W said something around 300 ft/lbs in the ones he has done that way in an old thread.

I just bought my 80 back after the guy I sold it to trashed it and the motor. I was going to do a swap but I found a rebuilt 3fe about 10 miles from me and I already have a turbo kit I bought off a mud member a long time back and never got around to installing it before I sold it. The new owner never installed it either. So i'll be doing that over summer.

A engine swap can be done fairly cheaply if you can do all the work yourself and find a good running LS and trans. But you are still going to be handing over a stack of Benjamins for parts.

I'd say read through some threads there are little things that can be done also. Do a cam swap, freshen up the head etc.

First i'd say make sure your motor is in tip top shape. Adjust the valves, do a complete tune up. Follow @jonheld advice in his numerous threads. Get compression numbers also.

a 2fe is also an idea but finding a good running 2f that you can bolt up to and use is expensive.... and finding a run down one and rebuilding is expensive. At that point you are nudging into the engine swap territory.

 

[tacocat]

While the 3fe is gutless I never really remember having issues with maintaining hwy speed. Drove in the mountains in CA all the time. People did say my 3fe drove better than theirs though.
I had 37's and stock gears on mine for a while... went up to 4.88s when I got the 39s.
When I first got the rig in 06 I baselined it completely, adjusted valves, and everything.

You will be going through a lot of nitrous if you are using it in that way.

Really you can do a camshaft and have the head redone and shaved to increase the CR. I think Mark W said something around 300 ft/lbs in the ones he has done that way in an old thread.

I just bought my 80 back after the guy I sold it to trashed it and the motor. I was going to do a swap but I found a rebuilt 3fe about 10 miles from me and I already have a turbo kit I bought off a mud member a long time back and never got around to installing it before I sold it. The new owner never installed it either. So i'll be doing that over summer.

A engine swap can be done fairly cheaply if you can do all the work yourself and find a good running LS and trans. But you are still going to be handing over a stack of Benjamins for parts.

I'd say read through some threads there are little things that can be done also. Do a cam swap, freshen up the head etc.

First i'd say make sure your motor is in tip top shape. Adjust the valves, do a complete tune up. Follow @jonheld advice in his numerous threads. Get compression numbers also.

a 2fe is also an idea but finding a good running 2f that you can bolt up to and use is expensive.... and finding a run down one and rebuilding is expensive. At that point you are nudging into the engine swap territory.

Holy crap, 39” and 3FE. The California mountains aren’t too bad. The slope from the west is very gradual, and while the east is steeper it isn’t bad. Our highway passes top out below 10,000 ft.

Its been a minute, but I think Colorado is a special kind of mountain driving where their grades are much steeper, 10K+ mountain passes are not uncommon, and the air is much thinner because of it.

Still, your 3FE sounds impressive.

 

[alex4640]

De-smog it. Remove the EGR and the CAT. Then the 3FE will prove all these idiots wrong. Of course, you'll have to live in a free country to do all that. Move to TX.

 

[lt1fire]

De-smog it. Remove the EGR and the CAT. Then the 3FE will prove all these idiots wrong. Of course, you'll have to live in a free country to do all that. Move to TX.

 

[ZIFFFZJ80]

Just wring it out. Granted I have a 1FZ, but I routinely go up the passes at like 4K RPM in 2nd on the steepest stuff and 3.5k in 3rd the rest of the time. Yeah, at first it feels like you’re really beating on it, but I’m Pretty sure it’s happier at higher RPMs vs slogging through 4th with your foot to the floor.

 

[DawtSpot]

Just wring it out. Granted I have a 1FZ, but I routinely go up the passes at like 4K RPM in 2nd on the steepest stuff and 3.5k in 3rd the rest of the time. Yeah, at first it feels like you’re really beating on it, but I’m Pretty sure it’s happier at higher RPMs vs slogging through 4th with your foot to the floor.

I found a nice steep hill by my house to practice on. Thanks for the advice!

 

[DawtSpot]

I just put in two brand new cats :/

 

[BILT4ME]

lol, I have to admit I have been driving it a little more cautiously than I perhaps should. Thanks for the advice on downshifting earlier. If I get up the nerve, I'll try it again, with that RPM range in mind. Thanks!

Realize that peak torque on that engine is around 3400 RPM. That means that's where it's "strongest" to operate under load. Use manual shifting to get it to and maintain it near that range.

Down shift early and hold it in the RPM range, up to about 4000. (I think red line is 5500?) It can run up near the redline for a while, but you may start overheating.