dixon700xx

I have a '98 toyota 4runner automatic v6 3.4 5vzfe engine. It has 90k miles on it I bought it used just a little while ago. shortly after I got it I replaced: plugs with new ngk dual ground plugs, ngk wires hooked all back up with dielectric grease, fuel filter, new air filter, and plugged the iac back in. It was unplugged when I bought it. now it runs pretty good under throttle. My driveway is at a slight grade and I back into with the nose pointing upward. and my in gear idle will go from 900-950 down to around 400-500 and bounce around and eventually stall if I don't bump it into neutral. Neutral idle is about 1400 (warm) and about 900-950 in gear warm higher cold. I know thats too high, but If I back it down any more using the adjuster on the tb it will stall in gear all of the time instead of just when backing down my driveway. I also been running injector cleaner every tank full. I think my iac valve may be defective seein as how I just cleaned my tb and maf sensor with carb and choke cleaner. Also whether I'm in drive or in low gear it will not run any higher rpms than 4800 it acts like it's hitting rev limiter yet redline doesn't even begin untill 5500. Somebody have some ideas? I really want to fix these problems.

dixon700xx

I just though of something I should probably check to make sure the hoses running to the iac are in tact and hooked up. Also maybe I should try removing it from the throttle body and clean it? Also i should be able to ohm the sensor out to find out if its functionable or not. does anybody know the spec?

dixon700xx

What is the 5vz-fe rev limiter? it has to be over 5500 rpms seeing as thats where redline begins. my '98 will not go over 4800 rpms no matter what i do. what may cause this? what should I check out? when i put the pedal to the floor and let the transmission kickdown it will run up to 4800 rpms and sit there bouncing off of it as if you hit rev limiter and wont shift till you let off a little bit. I have no check engine lights. yet I need to find my obd II port underneath the dash and hook up to my code reader to make sure there is no codes. I'm also going to stop in at advance sometime because their code reader may be better. Any help and advice will be much appreciated.

Elton

5500 .

Xeo

Thats weird my old man's 98 4Runner goes over 4800 when he rips it and my 90 4Runner goes up to 5000+ when i mash on the pedal (3vze scary as hell, but sounds so awesome also the gas gauge needle drops 1mm ), anyways the obd II connector should be on the bottom left side near the hood and gas door release levers. You might need to get on your knees to see it in case you cant feel it out. Cheers.

Elton

lol do the deckplate and isr mod to that 3.4 whole different beast

MKtaco_98

It's 5500 redlines at 5200 but the rev limiter stops it at 5500 I have a k&n air intake on my 98 Tacoma idk if thats what makes the difference tho intake came with my Tacoma when I bought so idk how it was before

redhawk427

Its on the bottom right side

dixon700xx

Ya, I was looking right at it... Made me feel a little dumb. Anyways I hooked up my code reader with the engine off key on and got 3 codes po300 po302 and po305 saying multi-cyl misfire on cyl 2 and 5(this would be historic codes correct?). After I put in new ngk dual ground plugs and ngk wires I did screw up the wire routing and had to correct it. It doesn't seem to run like it's not running on them 2 cylinders though... I mean with 2 cyl not firing it would idle rougher than all hell all the time. so I started it up and let the code reader erase the codes as it was running and they didn't come back on. I'm going to check it again after I drive it to work tomorrow to see if them 3 codes are back. Also I noticed that either my cel bulb is burnt out or was removed to cover up a problem. Also if you've seen my other thread you'd see that I'm having another problem which I believe is with the iac or possibly a vacumn line. needless to say there may be more codes, but my code reader isn't picking them up it's a cheap one from harbor freight.

dixon700xx

Also I plan on doing the deckplate and isr mods after I get all of my problems fixed, then I'll probably drop in a panel k&n after my paper filter take a ˟˟˟˟. I also have a bad spiral cable or otherwise known as a clock spring.

aa1911

iTrader: (1)

x3 on the 5500, mine cuts right there... (5speed tranny btw)

for OBD scanners, if you're not happy with the one you have already, there are plenty of decent ones in the $45-80 range or go with a computer based one like I have from Palmer Performance Engineering, it does everything you could possibly want/imagine but it's also $200 and you need a laptop to use it.

I highly recommend the deckplate mod, I ran mine that way even with the SC on and loved it, plenty of airflow and you retain the ability to close it up for puddles... I did a custom intake after the deckplate mod and although she looks nice and flows a bit better, I now have to improve my isolator to keep the heat/water out of the filter, kinda wish I just stayed with the deckplate. best $10 mod you can do!

I'm not impressed with K&N's seeing as how expensive they are but they do work great, just had to swallow hard when I paid $65 for the stock size filter. speaking of which, I have one! has about 15k miles worth on it but it's fine, make you a killer deal on it, just PM me if you want it...

where are you at in PA? I grew up in Boalsburg (State College) area...

dixon700xx

I'm from the DuBois area so I'm not to far from the state college area. also I'd love to get that K&N off ya, but I just don't have the spare money right now... Does anyone know what would cause it to hit rev limiter at 4800 even in neutral it won't go over. It wouldn't bother me so much if it would shift when it hits it, but it doesn't... if i get the codes 0300 0302 and 0305 again tomorrow I'll have to check out cyl 2 and 5... could there be a problem with my ecm?

marko3xl3

I'm not sure if this is applicable in your case, but there's actually ways for an this engine not to fire a couple and still fire relatively smooth. It depends which one it's not firing.

If that's the case, then it wouldn't be uncommon for it not to be able to reach top RPM considering it's dragging two pistons around.

You should check for fuel, spark, and compression in all cylinders and see if you find anything out of the ordinary. That would be the easiest diagnostic.

Beyond that, you might be looking at broken ignition components, maybe even the ECU. It's really hard to tell without digging further though.

Last but not least, I've seen some fleet vehicles where an additional rev limiter was installed to discourage drivers from over revving the engine. Those usually aren't synchronized with the transmission so they wouldn't allow it to shift right, confirming your symptoms.

aa1911

iTrader: (1)

^kinda like driving a U-haul nowadays, can't go over 75mph!!

I recently found a cylinder not firing right in my runner due to a stupid spark plug working it's way loose... still ran smooth as could be on 5 cyl!

does the truck bog down suddenly when you hit the limiter or does it just stop accelerating there? If it's actually the rev limiter, I would think you should be feeling a distinct cut/thrown forward for a moment then picks back up... just a thought

won't be back to PA til at least summer this year...

dixon700xx

it doesn't feel quite like a rev limiter normally does like a rev limiter you can feel it hit bounce as if you let off and hit again this thing just sits there and bounces from like 4800 to 4900 till i let up. I've been running my code reader every chance a can get and it hasn't pulled any codes since then. Also I did notice this box under neath the left side of the drivers side dash. down by the kick panel it has a bunch of wires running into it piggybacked onto a bunch of wires under the dash its about 2"x8"x1" it says auto command on it and has a small toggle switch that was taped to it and it's in the on position. I noticied it when I put in my fog lights... I never turned the switch off because I don't know what it is and didn't want to screw anything up... could this be an additional rev limiter box? i have a pic of it I gotta find it then I'll post it up

marko3xl3

It could be. That box definitely isn't standard equipment. You can go ahead and turn it off just to check if it fixes your problem. If it does, then you should be good to go unless that box was controlling something else also. It's really hard to know until you try it out. I doubt anything is going to go wrong if you flip the switch just to test it.

Also, I've seen cars now a days with rev limiters that don't bounce at all. Electronics are getting a lot more advanced and there's some very fast switching units out there to the point of where it bounces so little you don't even notice it.

dixon700xx

I'm not real sure I turned the switch off last nite, but I havent gone out and drove it yet. It still started fine. I don't know what I'm going to do with the box if it fixes the problem I'll probably cut all of those wires off and repair the wires... I'd post a picture of the box, but it's over 48.8kb.... because I took it with my phone I figured I would of been able to load it right up, and I don't feel like going through photobucket right now... Also being a '98 it isn't too much of a new vehicle. Also I'm pretty sure it's firing on all cylinders I have never gotten the codes again and I've been running the code reader constantly. Also I think it would be a little more doggie if it was missing on 2 cylinders. I kinda of hope that stupid box was why it wouldn't turn over 4800. I really don't know what else it could be. The only other thing I think it could be would be a problem with the ecu... Which is very bad because ecu's are quite expensive... because all of the actual rev limiter stuff is inside the ecu and the ecu just tells it to cut fuel real quick right?

dixon700xx

Last night I looked and made sure all of the vacumn hoses were hooked up including the 2 running to the iac. They all look to be in ok shape, but it doesn't sound like there is a vacumn leak... could my iac be defective? wouldn't it throw a code if it was defective though?

terminator

iTrader: (1)

I don't think you clean the MAF with carb/choke cleaner but rather you should use electrical parts cleaner so that may be part of your problem. If you need one I have a spare I can unload for a good price.

Also, I had a similar issue with a rev limiter feel on my 96 Limited 3.4l. Turns out the shop I took it to found out that the woodruff key was slightly worn causing the pulley to have some play in it. When I'd hit the throttle for passing gear it would go to around the same RPM as you and then bounce like a rev limiter until I let the throttle go, then it would shift and be perfect. It was an expensive fix so you may want to consider that.

So to sum up, MAF may be damaged and woodruff key could be damaged. GL dude.

dixon700xx

Ok, I took it to the dealer I bought it off when I wanted him to fix a few things, he said that his code reader pulled up sayin the iac is bad which would cause the stalling when in gear. I need to talk to him again though because he said it was unplugged and I want to know where at because I had it plugged in underneath the throttle body. Also this woodruff key what pulley is it on? I'm quite mechanically inclined so it shouldn't be much of a problem for me to fix. are you talking on the crank pulley? Also if the maf was damaged wouldn't it throw a code? I guess today I'll swing by advance today see about maf cleaner and maybe have them, put their code reader on my 4runner... I've never had so many problems with a vehicle. This has been very discouraging. Just like when I was under it the other day greasing it and putting some undercoat underneath I found the the housing on the back of my rear end is rusted extremely bad and gear lube is seeping through it... I need to call the warranty company of the warranty I bought from the used car dealer to see if it would be covered and also see if they would cover the iac... ugh if not I guess I'll have to figure out a way to patch my rear end housing and spend a lot of money on the iac... Also I did some research the box under my dash is just a remote start box... Somebody just didn't sell the remotes with the suv.