v6 3.4 wont rev above 3k

[robbie]

Hi im new to this forum and based in england where my truck is known as a surf.

My car was running fine until it went into the garage for a service. After changing the plugs it developed a missfire. They ran some diagnostics and found a lead to be faulty, so all the leads were changed and it was ok.

But after picking the car up i found out in neutral or any gear it wont go above 3k and sounds like its hitting a rev limiter. Under 3k it drives perfect.

I took it back to the garage and they had it for a week and could not find the cause. They re-checked the plugs leads and coil packs everything. All they could suggest is that i took it to a toyota dealership.

I did change the battery a week before the service, but noticed no problems. Also the garage took the exhaust off for welding and my 2wd to 4wd switch just flashes on the dashboard now however i can hear it click from outside the car when pressed. Can anybody help?

Its a 1996 5vz-fe V6 automatic ssr-g

 

[gofaster]

I had a misfire once and raw fuel got in the catalytic converter. The fuel ignited and melted the honeycomb inside and restricted exhaust flow. Worst case I guess..

 

[robbie]

After the missfire it passed the emissions test with the new leads, so im hoping its not that.

 

[JohnsD90]

Did you change the spark plug wires? Those gave me a misfire.

 

[BTO]

If the problem started after the shop changed the plugs then it stands to reason that is the cause for the problem. What plugs did they install? The plugs that go in the 3.4 are dual side electrode type. They cannot be gapped the usual way. It requires the use of a wire gauge sideways.

 

[01t4rnr]

another reason i do most all my own service work. id check fuel filter , pump, try cleaning the MAF, clogged cat? could very well be electrical issue if you have blinking lights however. good luck

** vacuum line dry rotted or might have come off somehow?

 

[Mr. Leary]

Sounds like a catalytic converter to me. Get under there and try to shake it, if there is rattling from the inside, its bad and the pressure from revving it up is pushing it up against the back of the catalytic converter housing and restricting airflow.

It also sounds like you have a few other problems, but the rev problem is probably an easy fix, although an expensive one.

A likely culprit for the flashing 4wd problem is that the actuator is not fully engaging. This is common in trucks where the 4wd has not been used regularly. The only way to really fix it is to pull out the actuator and clean it up or replace it. You will be able to manually actuate it in the meantime if you need to to avoid damaging your transfer case. I would recommend doing this sooner rather than later.

Pull the actuator off of the transfer case housing and you will see a notched bar that the actuator motor mounts on. Check this for buildups of gunk and old grease. All the way forward should be 2wd if I remember correctly, and 4LO will be all the way back. Make sure to put it back in so that it matches the t-case gear that it was in when you pulled it apart (such as 2HI). Once you have cleaned it up and put it all together, the actuator motor should be able to shift it. If not, you can either repeat the process or replace the actuator, using the same process.

Hope this helps.

 

[robbie]

Wires were changed and the cat is ok. I have the plug part no Its T09091901192

 

[Jon]

If u end up fixing it or have to take to a stealership I'd make the original shop eat the $ (sorry no euro sign). To check the cat I'd drop the exhaust upstream from cat and give it a go. Also might try resign the ecu by disconnecting the batt for 15 min. Good luck

 

[TheDurk]

This is a tough one because many of the things I can think of would throw codes on the US post-1996 On Board Diagnostics II (OBDII) system. I have the idea that the implementation of OBDII varies a lot by country. My '97 Brazilian HiLux SW4 (a Surf in Japan) does not have it so I suspect you may not have it either.

So one possibility is you are stuck in open loop mode which can limit high revs. However, lots of things could cause open loop, but most are things the shop should have caught even with the older on-board diagnostics and would set a CEL. I'll take a shot in the dark and suggest you check the wiring to your O2 sensor(s) on the exhaust since they were messing around there. (I'd also check any wires into the tranny and the transfer case regarding the 2WD/4WD problem.) Exhaust leaks, coolant temp sensor--actually, lots of sensors, could cause the open loop issue. But our motors would usually be able to tell us what was wrong. Do you have a Check Engine Light on? The old OBD system could be read with a paper clip.

 

[robbie]

No check engine light on but i have heard that that in itself can be a fault. Basically the engine light should have come on to show up the fault but has'nt. Im taking it to a toyota specialist in the morning and then i will let you know. The 3.4 v6 is rarer in england than rocking horse poo.

Thanks guys ^ for trying to help. I will let you know more when the shop has looked at it.

 

[bmcnutt]

How did you make out, I am having the exact same issue ???

 

[TFJ-4runner]

I doubt its your problem but I bent a fuel line on mg while wheeling once. It made the rubber part kink and chocked my 4runner about 3k rpm. Just another thing to check maybe if there was foul play on their part.

 

[coinball]

Let's start simple - did you confirm the new lead are actually connected properly (i.e. the coil packs are paired with the proper spark plug on the other side of the motor)?

 

[bmcnutt]

make sure your crank pulley is tight, or it couldbe your crank position sensor. I had a lot of problems with my 2000 not revving past 3000 rpm, and that was it

 

[robbie]

I know this thread is old but i thought i had fixed the issue. The heat shield around the pipe located in front of the cat where the pipe goes across the vehicle and up into the engine seems to have been the issue. It had been filled and when i poked it and made a small hole the revs went all the way back up to the red line. I had no issues for 6000 miles but i had to pull the bottom part of the shield away as it had rusted one part clean off and the fire resistant material all fell out. Now i am back to square 1 the truck wont rev past 3k.

Surely just a heat shield cant cause this issue but whenever i messed with it the revs changed. Does the temperature of this section of exhaust cause any errors when it gets to the cat. I have no check engine light and its not the crank sensor.

 

[mattleegee]

so are you guys dealing with a kick back at 3000rpms? like a rev limter?
or is it just sluggish/hesitant at 3000rpms where the rpms go a little/LOT slower then normal?

 

[robbie]

It starts to miss at 3k when revving slowly then if you rev it harder it kicks back.

Its had new maf and o2 sensors.

 

[robbie]

Also it has full power up until 3k and runs superb. I have to feather the throttle and sometimes reach 3.5k but it normally kicks back.

 

[robbie]

Now the truck wont rev above 2.2k. First time i started it up for a month and revs to 2.5k cold but once warm wont go above 2.2k. Anybody got any ideas all Toyota dealership can do is suggest ecu replacement!!!!! They cant find the solution!!!!