Offroad-Express

My 1kz-te has recently been dropping a cylinder between 2250rpm-2800rpm at full throttle only. only seems to be one cyc dropping out. has egr valve blocked off and butterfly removed, running 11-12psi boost. changed fuel filter which improved it a little. was wondering if there is a over boost cut built into the ecu as may be reaching it as boost goes up and down from 9/10psi to 11-12psi as it drops a cyc but doesn't seem to blow any smoke while missing. any help/thoughts would be great

If you've got a fuel flow problem, then high revs is where it'll be most apparent.

Easiest way to test a boost cutout would be to up the boost and see what happens.

I had a similar prob a while back with mine, turned out to be the bolts had sheared off the main idler gear. Problem only showed up when at a certain rpm when engine would shake like a cylinder was missing. had several mechanics check out without any success. In the end I removed and checked sump for metal. Loads of teeth in there from idler gears, removed front end replaced with second hand gears and new bolts, easy fix, running sweet ever since. My recommendation If no-one has better suggestion is remove and check your sump. Good luck.

KiwiBacon wrote:If you've got a fuel flow problem, then high revs is where it'll be most apparent.

Easiest way to test a boost cutout would be to up the boost and see what happens.

yes i agree but above 2800rpm it runs fine through to red line. may have to try up the boost and see what happens

as for the idler gear it could be possible but there is no metallic sound that i've noticed but may have to have a closer listen to it but i would not have thought it would have been noticeable all the time as it's only at full throttle if i back off 1/8-1/4 throttle the problem goes away

had a bit of a play with it today. read ecu faults which was 35 - air pressure sensor, so i unplugged the sensor and took it for a drive and it was underpowered something wicked . so i plugged it back in and it still missed between 2250prm and 2900rpm. i reset the ecu and checked for faults and they had all cleared. so i went for a drive but still missed at same points and ecu fault didn't return. so i took off waste gate line and it reached 2250rpm @ 11-12psi and started to miss til it got to 2900rpm where it shot up to 18psi with little increase in power. checked over engine for and abnormal sounds. it has me beet as to whats wrong might give it a few days and see if the ecu faults anything.

hey my m8 has a 1kz-te in his surf and had a simular problem when he wound his boost up so he got an after market ecu with a little control box so he can adjust how much fuel the motor gets at high or low revs .... this fixed the problem because the more boost you run the more fuel your engine needs to handle it i think. he now runs 13 threw the engine and its great. (the ecu controler only cost him $150 i think)

flexy wrote:hey my m8 has a 1kz-te in his surf and had a simular problem when he wound his boost up so he got an after market ecu with a little control box so he can adjust how much fuel the motor gets at high or low revs .... this fixed the problem because the more boost you run the more fuel your engine needs to handle it i think. he now runs 13 threw the engine and its great. (the ecu controler only cost him $150 i think)

Can you get the make/model of the control box for us? I'm looking for that for a different application.

Rugger, any chance you can get another air pressure sensor to swap over and test?

yea sure i should hopfuly see him tomorow and il ask him

flexy wrote:yea sure i should hopfuly see him tomorow and il ask him

hell year i'd be keen on that if it's that cheap. but don't think it will solve my problem as i never use to have this miss which is what has me confused.

as for replacing it i have every other bit to swap except that sensor as i have a complete spare eng but the pressure sensor is broken although i just realised a mate of mine just got two 1kz-te which he's converting to mechanical pumps so may see if he has a spare sensor. thanks for the idea KiwiBacon .

swapped the pressure sensor with my mates one today and didn't change any thing although the ecu faulted the pressure sensor again so may be a wiring fault or ecu fault. any one on here got one of those diagnostic tools for checking the signals?

i'll be away till next weekend then may have to look into it a bit harder or i was thinking of building up my spare engine with a mechanical pump & intercooler, there's a guy in town somewhere who takes the 1kz-te pump and a 2lt pump and builds up a mechanical pump thats good for 180hp @ 20psi boost for $800-$1000 if you supply the pumps then i'd have to sort out intercooler but may have a parado one lined up

does the system run a air flow sensor of the hot wire kind, my ford had issue at full power, back off and it ran fine, cleaned the hot wire unit and it cleared a heap of issues up, could be it is seeing less air than actual flow.

pedro

1rugger wrote:there's a guy in town somewhere who takes the 1kz-te pump and a 2lt pump and builds up a mechanical pump thats good for 180hp @ 20psi boost for $800-$1000 if you supply the pumps then i'd have to sort out intercooler but may have a parado one lined up

Those figures are doable. But you'll need a good intercooler to go with your 20psi boost.