Outer Limits 4x4 Board

I have an 89 Hilux with 3rz conversion it's missing/surging at around 2000rpm but it's only noticeable under no load. eg. when idleing and i bring the revs up to 2000rpm it will have a definate miss which will go away after 2800rpm. It does the same thing if cruising at 55-60kph in 4th it will start surging (feels like im jabbing at the throtle) It also seems to lack power below 3000rpm. Fuel supply is not the issue, just had injectors cleaned and spray pattern checked, running aftermarket fuel reg (set at 45psi) and pump. What things should i be looking at?

Also not sure if its related but if i drop the fuel pressure to 38psi (which i think is factory) it struggles to idle at all.

Any sugestions appreciated
cheers

blockage somewhere? You have pressure, but do you have flow?

oldmate wrote:blockage somewhere? You have pressure, but do you have flow?

Yeah mate im getting nearly 2 L/min out of the return with the engine running. If it was a flow issue id expect the issue to exist at higher rpm

has it always been doing this or just started?
how much fuel does it chew?
do you have engine light hooked up? is it on?

YN67highlux wrote:has it always been doing this or just started?
how much fuel does it chew?
do you have engine light hooked up? is it on?

Has always done it
uses about 16L/100km
engine light not hooked up

mine was doin the same thing. couldnt notice it in low4 but on the road it lagged alot. ended up being the knock sensor wire was cut..
other things id do are hook up speed sensor if you havent already and have you hooked up a purge valve yet?
on the computer with it facing sticker up and the plugs facing you its the left one 26 pin i think. on the top youll have the following wires
empty
empty
empty
red
black
empty
empty
then black and white this is where you plug the purge valve neg wire into and power it into main acc.
i also ran a hose on my return line in fuel tank away from the feed line as is was playing silly buggers with the pump.
also what air intake setup have you got? i ended up changing to a genuine air box as what i had was creating an unstable airflow. and what have you done with vacume lines?

Is this a new problem, was it going ok before? Clean the air flow meter, its between the air filter and the throttle body. Use brake clean or contact spray.

the gun wrote:Is this a new problem, was it going ok before? Clean the air flow meter, its between the air filter and the throttle body. Use brake clean or contact spray.

did you read the last post?
if it is dirty id probally use an afm cleaner. sold at super sh1t for 20 bucks

YN67highlux wrote:

the gun wrote:Is this a new problem, was it going ok before? Clean the air flow meter, its between the air filter and the throttle body. Use brake clean or contact spray.

did you read the last post?
if it is dirty id probally use an afm cleaner. sold at super sh1t for 20 bucks

I have cleaned the AFM, i will try the other things you have mentioned. Cheers

YN67highlux wrote:

the gun wrote:Is this a new problem, was it going ok before? Clean the air flow meter, its between the air filter and the throttle body. Use brake clean or contact spray.

did you read the last post?
if it is dirty id probally use an afm cleaner. sold at super sh1t for 20 bucks

So what in the last post refers to cleaning the AFM?
And seeing that I have both brake clean and contact cleaner, why would I waste $20 on afm cleaner from supa crap? When either of these products work. Bad day? Pmt? Just settle pettle.

if it has always done it since the conversion check your earth wires or even add some more to the motor its supriseing what a couple of good earths can do

crispy zook wrote:if it has always done it since the conversion check your earth wires or even add some more to the motor its supriseing what a couple of good earths can do

no shortage there, if anything ive gone overkkill. i have two 70mm2 earths to the motor and one to the body.

I was thinking it might be a bad coil??

does anyone know how much pressure the stock 3rz fuel pump can handle? I want to run aroung 45psi, would it handle it?

Yea itll handle 45psi.
Coil packs on these do go, but normally they just die, could pay if you know some1 with a 3rz to change them around. When its idling and you are behind it, can you smell fuel?
Whats your air intake look like? Is it the stock 3rz plumbing? Have you had the bonnet open in the dark and brought it upto those rpms to check if it has stray spark? Why it would do it at only those rpms is beyond me, but its something simple to check.

my susgestion is to plug it into a dignostic computer because it sounds like a sensor of some sort
could be money well spent.

Rory wrote:Yea itll handle 45psi.
Coil packs on these do go, but normally they just die, could pay if you know some1 with a 3rz to change them around. When its idling and you are behind it, can you smell fuel?
Whats your air intake look like? Is it the stock 3rz plumbing? Have you had the bonnet open in the dark and brought it upto those rpms to check if it has stray spark? Why it would do it at only those rpms is beyond me, but its something simple to check.

cheers mate, i dont know anyone with a 3rz so i would have to buy brad new ones. Can smell fuel in exhaust but it is using allot of it. Intake is far from stock and this will be the first thing i try, im going to change it completely back to stock. I WIll aslo check for spark shorting somewhere.
Cheers

Red868 wrote:my susgestion is to plug it into a dignostic computer because it sounds like a sensor of some sort
could be money well spent.

I will ring Toyota tomorrow and see how much they want t do it.

cheers

youll probaly find toyota wont be able to help you. when i took mine in the diagnosis port didnt work because it needs stuff plugged in behind dash to work. i had to go see an auto electritian who got the codes out of it some how. id be starting with airflow myself.

did you check your knock sensor? wreckers had sling around intake manifold when they pulled mine out witch ripped the wire out. they are hard to see and get to.

YN67highlux wrote:did you check your knock sensor? wreckers had sling around intake manifold when they pulled mine out witch ripped the wire out. they are hard to see and get to.

na to be honest i havent done anything about it yet. where is the knock sensor located? more than one?

Knock sensor is underneath the intake, next to No 3 cylinder. 1 only. Check for continuity between body and plug.

yamaha__308 wrote:Knock sensor is underneath the intake, next to No 3 cylinder. 1 only. Check for continuity between body and plug.

Will do mate, dou you know if it is piezoelectric or piezoresistive type knock sensor? what should the resistance be if there is no detonation detected?

YN67highlux wrote:mine was doin the same thing. couldnt notice it in low4 but on the road it lagged alot. ended up being the knock sensor wire was cut..

Seems strange because the workshop manual i have says there should be no continuity between connector on knock sensor and earth. If your wire was cut you would have no continuity which is the desired result? (I have a tacoma workshop manual)


got home and unplugged the knock sensor, it made no difference to how the car runs. should i be changing the knock sensor?

hmmm id start looking at airflow first. can u post a pic of your setup?

put this setup together to get it going and it kinda stayed that way. As you can see its not even close to being stock

Were abouts is your afm now?? Did you have to extend the cables to it? Was it a sheilded cable??? Most are, did u use sheilded cable?
Also, from memory they are pretty touchie bout were it is places, id try moving it closer to the stock postion if you can easily and see if that helps.

Edit - Is that it right infront of the Throttle? it maybe too close, try moving it further down the intake.
(this is assuming that is the AFM)

yea man that is way too close. how is it fixed into the tube? needs to be moved down to where the oil filler cap is. ill get a measurement tommorow for ya of the diameter pipe that should be there and how far the airflow meter is away from throttlebody. its to cold and wet atm.

http://cgi.ebay.com.au/Brand-New-Petrol ... 2559576e39" onclick="window.open(this.href);return false;
you need one of these. with a bit of panel adjusting they just fit. youl have to move your battery to the other side. not to hard, the battery holder you have now shoud just be tek screwed in, just take out and screw into other side and brace it. i had to push raidiator overflow bottle right next to radiator to fit battery aswell.

cheers for the feedback guys, yeah the AFM is about 150mm from the throttle body. I am looking at this air box, looks the same as all the others but its an aftermarket one, am i better off going genuine?
http://cgi.ebay.com.au/ws/eBayISAPI.dll ... K:MEWAX:IT" onclick="window.open(this.href);return false;

Does the pipework size matter from the stock air box to the throttle body? Should i try keep it all factory or can i use any size flexible tubing?

Id try and keep it the size of the throttle body, which is also the stock size. I only ever had the afm in the stock location.
I would def move yours back tho, it maybe at those rpms there is something funny going on in the intake that gives the AFM funny readings(turbulance or something).