kbow18

I have a 1991 4Runner with the 3vze V6 and 5 speed. My problem is that there is no power whenever I put the engine under any load, I can't even get it to move on level ground unless I risk burning up my clutch.

If there are any ideas as to where to start looking, please help.

ChickenLover

The 3VZE is notoriously underpowered (and in most cases unmaintained). What you are experiencing is probably normal. I recommend a complete tune up.
-cap & rotor
-spark plugs & spark plug wires
-ignition coil
- Upgrade to a K&N or Amsoil air filter
-fuel filter
-pcv valve
-check timing

With a weak engine to begin with, if any of the things mentioned above are worn or are in need of replacement you will experience a considerable loss in power. You might want to make sure your brakes or bearings aren't too tight - putting even more strain on your engine. Exhaust and intake modifications are a great way to get power out of your 3.0.

When I first bought my runner it had not been maintained worth crap. I could barely get it to go over 55 mph. After a little tune up work and with my current mods it is actually pretty fast. I can now tow my friend's fat girlfriend around in a bean bag chair in my dump trailer (approximately 5k lbs.) and still maintain the speed limit....Lord, I apologize.

colsoncj

If you have some serious power problems, and can't get to the bottom of it, do a compression check.

kbow18

Well, the engine was just rebuilt. Also the lack of power I am experiencing is quite obvious. I can't even accelerate past 40, and it takes me about a minute to reach that speed.

nunsa

Did this start happening right after the rebuild or has it been awhile?
I would check the obvious first, timing = 10 degrees, spark plug gap = .031, fuel pressure = 38 - 44 psi, check and respec your TPS, check your vacuum lines, Check for air leaks on your air intake, check your timing - might be a toothe off., Check your Throttle cable adjustment.
How does it idle? Does it miss or anything?

Good Luck!

* Harry *

gwhayduke

First thing I would check, being a 1991, is the fuel filter. Lots of guys on here report being told that Toy fuel filters are lifetime units, which is bunk. No fuel, no power. Swap it out before you do anything else.

Scarface

On the 3.0 how hard is it to get to the fuel filter? I have a severe case of being slow, it's like when I pull out in traffic onto the highway I have to make sure that there aren't any cars coming for a good ways because it takes a loooong time to reach 45 mph, then it seems after I get up to 55 it isnt so bad...I know yesterday when I was in 2 low i was on a slight incline on a dirt road and i had the pedal to the metal and i just sat still at about 3k rpms, wouldn't go anywhere, had to drop in 4 low and it did fine...

gwhayduke

You have a serious problem if you're having those problems in 2nd gear and low range on a dirt road.

The FF is above the transfer case crossmember on the passenger side, tucked back into the frame rail. Unbolt the passenger side crossmember and let it drop down about 2 inches. The FF will be much easier to get to. Be very careful with the banjo fittings on the FF...dogear them or cross thread them and you'll be buying a new fuel line. Loosen the gas cap before removing the filter to release the pressure or you'll get about 2 gallons of gas dumped on you as you remove the filter. You will still spill gas, so DON'T use a drop light...a headlamp or flashlight.

If you take it to a mechanic it will cost about $75. Use only Toy or Purolator filters...They're both pretty good.

TRunner

I just got done with my full rebuild less then 100 miles ago. I have the same problem. I didn't replace the feul filter yet because I started to and rounded the corners of the feul line nut. That thing is harder to replace then the whole engine! I am rather sure the timing is right. The belt marks all lined up with the cog marks and it idles great. There just seems to be a loss of available power, like lack of feul oir something. I know the injectors were just cleaned and tested at 99-100% so they should be fine. I did have to adust my throttle cable to get full throtle and take the slack out. Timing is at about 10 BTDC. Spark plug gap... I duno realy, I just put in my v-power ngk's as is. Would a bad PCV valve behaive this way?

nunsa

What's up w/these 3.0's and loss of power after rebuilds? :pat: :pat:
When you do your fuel filter a line wrench comes in handy.
Spark plug gap =.031, Fuel press: 38 - 44psi, Timing 10 BTDC.
Myself, I only run Toyota Plugs, the others just foul out and don't last that long for me!
Did you adjust your TPS? To spec? Check fuel press and regulator? No vac lines disconnected or crossed? No air leaks on the air intake? No codes?
Remember what I Told you all: "Replace the Knock sensor and wire while you have the 3.0 apart!"

Good Luck!

TRunner

no codes yet...

You told me about the knock sensor?
Needless to say, mine is still in there... probably original, too!
I will check all the other stuff after I get my filter changed and update you guys.

TRunner

I think I am attributing a lot of my problems to a bad cat as it turns out. I am replacing it this Friday so I will let you guys know for sure.

ctcost

Mine did the same thing after the rebuild...Going to Tahoe it just crapped out...It needed to be rebuilt again (red freebie warranty...and they did a much better job the second time around)...After that is when I got the truck and it runs great now!!! If the compression and everythign ck's out it might be a fuel filter if you haven't done it for awhile and yup the thing is a bitch to reach (It's located under the frame on the right hand side...) You'll need a 3 inch extension and a universal joint for the socket...I think I used two...the whole procedure took a half an hour...

If it does it in nuetral and it isn't the compression or anything related, (ie you aren't getting power in nuetral)...replace the fuel filter...also you might do the seafoam treatment as there may be a whole bunch of crap in the intake (there was in mine with 190k on it)...If none of the above helps take it back and tell em...Fix it! Before the warranty fades on the rebuild.

TRunner

Yup... Pulled the O2 sensor and it ran much better because it gave it some release from the back pressure. The new cat will be installed Friday and I'll update more then.

ctcost

Oh yeah big yup on the knock sensor replacement if your check engine light comes on intermittently and you lose power @ the same time.

TRunner

and all is well again. I'm back to the original slowness instead of the Geo Metro power I had. The Muffler Shoppe on ebay has the best prices and hooked me up with fast shipping to get it to me by the weekend. Very helpful with any questions, too!

Scarface

My next thing is going to be to get my manifold leak fixed, then a new exhaust system and cat, maybe that will help, I know mine sounds like dookie now!