1KZ TE Injector Pump Resistor Modification

[jordan_sorabjee]

Sorry if this has been done to death on here before.

I've been reading/watch plenty of stuff from Oz about resistor Mods. Seems very simple and not sure of the downsides. One thing I cant work out: What does the resistor mod actually do? does it just give you more range to advance/retard the pump or is it more complicated? My pump is the old style that you can do this mod to.

The reason i ask is that i have recently had my pump replaced for a refurbed one. It is running really well, but at low revs it throws a CEL. This is because the pump is overly retarded and needs advancing slightly (plenty of videos about this also). As is it running so well i don't really want to do this. Does the resistor mod give it more range to advance/retard or is it doing something different entirely?

Thanks in advance.

 

[Shayne]

It just lets a little more fuel in hence increasing power .

1kz te fuel pump tweak.

hi, i am new bie here, i heard there was a vidoe here to show how to tweak the 1kz te fuel pump. can any body help?

www.landcruiserclub.net

 

[jordan_sorabjee]

Cheers for the reply Shayne. Sorry for being simple. Would that not be the fuel resistor (beige) not the timing resistor (grey)? I should have said it was the timing resistor that I was interested in knowing about. Also how is that different from adjusting the spill control valve nut?

 

[Shayne]

Ah i have no idea about electrickery i'm afraid and i've never heard of that mod the spc nut and a little more boost makes a big difference but for me it was all mixed up with adding an intercooler and 3" exhaust .

 

[jordan_sorabjee]

Ah ok. Hopefully someone else will know. Thanks again.

 

[Grimbo]

Not sure how it works on a 90 but on early mechanical/electronic hybrid pumps on tractors they had an electronic "Power Boost" that as the tractor started to work harder and the boost pressure raised the pump would electronically increase fueling ....this was managed by a boost sensor in the inlet manifold..... a common "tweak" was to add a resistor of the correct value to the return wire from the sensor and this fooled the pump ECU into delivering more fuel at lower revs or giving 50% power boost all the time.... guess this mod is similar .

 

[Shayne]

That enlightens me some Grimbo because the 1KZ-TE does the same when the turbo kicks in .

 

[chapel gate]

Not sure how it works on a 90 but on early mechanical/electronic hybrid pumps on tractors they had an electronic "Power Boost" that as the tractor started to work harder and the boost pressure raised the pump would electronically increase fueling ....this was managed by a boost sensor in the inlet manifold..... a common "tweak" was to add a resistor of the correct value to the return wire from the sensor and this fooled the pump ECU into delivering more fuel at lower revs or giving 50% power boost all the time.... guess this mod is similar .

sounds like the electronic version of the boost compensator fuel pin.

 

[Shayne]

I can't grasp the benefit of it in the 1KZ . ECU takes a message from the boost sensor and increases fuel accordingly .

If i understand correctly (and i'm not sure i do) to mess with the resistor seems rather pointless when the nut increases fuel throughout the rev range and the ECU continues doing what its supposed to do regardless .

 

[jordan_sorabjee]

Thanks Grimbo. Again, I think this explains what the Fuel Resistor does. My understanding is the screw on the SPV affects the fueling across the whole range of RPM whilst the resistor mod largely affects the lower revs. I believe this was for emission control. What it still doesn't explain is what the timing resistor does. It seems to me that people are stick the resistor into the connector without any further adjustment to the pump and claiming better power and lower EGT. I don't understand this as the pump timing is entirely mechanical?

 

[Shayne]

Tuned for traffic jams

The turbo is the key to unleashing the beast the 1KZ can be , boost might have been set as low as 6psi at the factory when new while 12psi is within spec (electronics dictate that limit) . Also the turbo exhaust downpipe is a terrible and restrictive design .

 

[jordan_sorabjee]

To be honest, im almost at the stage where i know i just need to advance the pump, i just want to satisfy my curiosity about what the timing resistor mod does and how it works!

 

[Davet]

The resistors apparently limit fuel and pump timing only in 1st & 2nd gear its main aim is to reduce exhaust emissions on my a
Australian 1kz-te i used a Dp chip
But after i fitted my water to air intercooler i took it off
It can be buggered with but it needs to be done in a shop and be adjusted on a pump test rig from what i have heard it can be a bit tricky and can be over adjusted very easily as all spill pumps are not exactly the same setting i put a brand new pump on mine and it goes great
And do remember that injectors require rebuilding and resetting approx every 100,000 klm
I am on my third set and 3rd head at 360,000 klm

 

[Shayne]

I fitted a top mount air intercooler/bonnet scoop , 3" exhaust ,upped boost to 12psi and adjusted the spill by feel .

Think my truck had covered around 140,000 miles when i visited the injector shop and instead of taking my money they said "nothing with injector problems sounds that good"

 

[Davet]

Can be lucky but spring tension starts to decline after 150,000 klm so i am not going to leave them until 180,000 as i did the first time to get Smokey and lazy but yes maybee i was unlucky
As a mechanic i would rather over service
Just saying

 

[Shayne]

Did you block egr yet ?

 

[Davet]

My 2002 1KZ-TE in Australi does not hav an egr but it ha the blank bosses where it would go hut not on the intake its a single 76mm butterfly

 

[Davet]

Wow my typing is average it seems

 

[Shayne]

I removed that butterfly as well i think .

 

[jordan_sorabjee]

I should have really followed this up ages ago. My CEL at low revs was not caused by the pump being too advanced or retarded. If was caused by a tiny break in the wire that connected to the timing correction resistor. For exactly the reasons that Davet points out this is why the CEL was being thrown at the low revs. After fixing the break, I re-timed it and that sorted it. If I remember correctly the code was also 14. Those resistors are used to finely tune the pump on the bench for timing and fuel. That might explain why the acceptable range according to the manual is so large.