1kz-te mystery problem - for the diesel experts out there

[steve74]

Hey Guys, its been a long time since i was last on this forum. A lot of guys were helpfull when i had my caldina so i thought i would pick some brains again as im having trouble with yet another toyota.
I purchased a 1998 3L turbo super custom van about a year ago. It run fine untill last weekend. I was heading up to nelson, giving it a bit of stick up the hills when i heard a soft clunk and a bit of a burning smell?

Anyway i imediately noticed a serious drop in low down grunt. With a head wind and bugger all load i couldnt get the van past 90kph unless i was on a down hill.

My mechanic cant look at it untill monday but ive looked at all the obvious things that he suggested with no luck? I even downloaded a manual and im still no further ahead.

It runs smoothly enough and starts fine.
I can hear the turbo cut in and out.
water is fine, its not over heating
No black smoke
exhaust seems fine
no fault code shows up when bridging out Te1 and E1 on diagnostic plug.
The cam belt looks ok - was replaced 17000kms ago.
injection pump is aligned and timed to markings
Fuel and oil filters done less than 5000kms ago.

Any other things i could check before i pay my mechanic to look at it?

thanks, steve

[Diesel PWR]

muffler internals could have callasped, i would check boost level, and map sensor voltage at full load, is it manual or auto?

[steve74]

its a manual, seems like plenty of pressure from exhaust at idle, i cant seal it with my hand.

could i unbolt the exhaust? - say at the flexi join and drive it to confirm or will that cause other issues??

[evil_si]

i would first check the turbo
even thou you can hear it, it doesnt mean anything
pull the inlet off and check shaft play / compressor condition
have you checked the air filter

check the boost pipes, make sure a clamp hasnt come off or a pipe split

[Crimson Tears]

I would recommend a compression and leakdown test. These are very common for cracking heads.

[Mr Revhead]

cracked head wouldnt cause that power loss though

id be doing as evil si said. also check things like the stop valve is opening correctly
if thats stuck it will be restricting the intake.

[steve74]

Cheers guys, will check those few things, im sure that my mechanic will do leakdown etc etc when he has the time. I was just hoping that it was something simpler. air filter is clean. Will let you know what i find.

steve

[evil_si]

definatly check the turbo and air intake system for pressre leaks before doing any leak down test etc,

[YeMs]

just put a boost gauge on it. run the vacuum from the plenum so u get true pressure going into the engine. see what pressure its got there and how it varys with load etc. from memory those 1kz's run up to 10psi. the map sensor also play up on them. have seen it a few times in the surfs, but not in a super custom.

they do crack heads/blow head gaskets but generally not if they havent been raped/loaded too much (for example towing 3 tonnes over the kaimais and not watching the temp gauge then wondering what the burning smell is) mind u there seems to be a mileage in common. they do around 200,000 k's before they start giving issues. but as long as they have been well serviced/maintained they wont give too much hastle. and on top of that, you definately wouldnt get that amount of power loss just from a blown headgasket. maybe sum overheating issues but not massive drop in power.

but yeh, like every 1 else is saying have a good look around the turbo/intake hoses etc. probly sucked a bird up or something haha, or that rat thats been living in your engine bay has finally eaten through the intake pipe and has now become part of your turbo.

[strx7]

d. also check things like the stop valve is opening correctly
if thats stuck it will be restricting the intake.

have seen this issue on a number of KZJ90 series prados which are the same vintage. vehicle goes to mechanics a number of times and they cant sort out whats wrong with it, turns out that valve is snuffing the intake.

[Mr Revhead]

yeah i saw it a few times at toyota
cant remember exactly where its fitted, but i think its part of the venturi section, we were often asked for prices on that.

[DFECTED]

also the exhaust recirculation thingys get stuck- they are on the back f the intake manifold with the pipe going around the back of the head to the exhaust. Pull the vaccum hoses off bung a small ball bearing up both and put them back on. I have seen this a number of times

[steve74]

also the exhaust recirculation thingys get stuck- they are on the back f the intake manifold with the pipe going around the back of the head to the exhaust. Pull the vaccum hoses off bung a small ball bearing up both and put them back on. I have seen this a number of times

i actually removed the vacum hoses from the solinoid which controlls vacum to that diaphram actuator thingy. the actuater lifts up with vacum. i bypassed the solonoid to lift the the actuator. i then went for a drive, still no go. you think i should block the vacum hose?

I dropped it to the mechanic today, he checked a few things such as timing and water level etc and cant fault it. he didnt realy have the time today to get into it so lets hope he finds something tomorrow. the fact that there is no black smoke is got him stumped.

[DFECTED]

hahaha the most obvious thing that nobody has said yet is change the fuel filter!

[Mr Revhead]

doesnt really sound like that, blocked filter often wont let the engine rev

[steve74]

hahaha the most obvious thing that nobody has said yet is change the fuel filter!

fuel filter and oil filter were done under 5000kms ago.

Still, its in the care of my mechanic now. im sure that he will go through a process of elimination. im just keen to see what it is?

[DFECTED]

on the same subject a mate had a similar problem, everytime it happened he would take the feed from the tank to the filter off and give it a blow and he would hear something drop into his fuel tank. It turned out when it ran low on diesel it would suck some shi t up that was in his tank blocking up the pickup

[steve74]

ALLL SORTED !!!!!

i wouldnt have believed it if he hadnt showed me.

A little filter the size of a bottle cap on one of the hoses had split. It was sucking in air giving the map sensor funny resistance values.

[Diesel PWR]

told ya to check map sensor voltage in earlier post.

[steve74]

yeah, i was sure it was an exhaust blockage. the mechanic measured the pressure from the hose and compared tit to resistance or maybe voltage?. when he traced back the hose he found it. i had had the hoses off it but didnt check the filter thing itself.

thanks everyone for your help, ive learned a fair bit about the 1kz in the last few weeks,