1UZ doesn't start (igniter?/timing?)

[melvinmelvin]

My 1UZ is in a boat, hence I don't know what car it comes from.
Its a front sump pre VVT 1UZ.
The crest on the top is Toyota, not Lexus.
My best guess is Celsior (same as LS400?)

Hauled the engine and did some work on it, now it will not start.
Changed the oil pump.
Changed the timing belt.
Changed the starter, (ie injector cables unplugged and piping removed)
And some other bits and pieces.

Trying to start some or all cylinders fire, can't rev it up, it runs
for about 3 seconds then stops.
Trying to start again immediately after it shuts down does not lead to
cylinders firing.
Waiting 3 to 4 seconds before restarting, results in the same,
some or all cylinders fire, cannot rev it, after 3 seconds it shuts down.

Whats wrong?

I have 2 ECUs, the behavior is the same with both ECUs.

I'm fairly sure it gets fuel.
The return/surplus/overflow pipe back to the fuel tank has a decent flow.
Haven't checked all spark plugs but 3, they smell heavily of fuel.

Maybe I have a problem related to igniters and missing sparks.
Re igniters I have a specific question.
One igniter has 4 wires connected.
The other one has 5 wires.
Re the 5 wire one:
from left to right the wires have colors as follows
1 - yellow and green
2 - red and black
3 - red and black
4 - yellow and black
5 - white and black
My tacho is connected to wire#2 (works fine with gauge set to 4 cylinders)
My question is: what is wire#4 used for?

My mechanic changed the timing belt while I was in Bangkok picking up
the new starter.
Could an error/mistake with the timing belt result in the above symptoms?

Ideas would be greatly appreciated.

 

[Zuffen]

Assuming the engine ran well before the oil pump change it should run well now unless something has gone back together incorrectly,

I suspect the timing belt has been installed incorrectly. Check the timing marks all line up. As your mechanic did it I'd have him double check it.

One question; why was the oil pump replaced? They seem to last forever.

Pin 4 on the igniter is the tacho feed and pin 2 where you're getting your tacho feed goes to the ecu at pin 67.

I don't believe pins 2 & 3 have the same coloured wires.

Make sure you're looking at the pins in the right order.

On the run for 3 seconds and stop it sounds a little like it's running on the cold start valve or the fuel pump high speed circuit and dying when the fuel pump drops back to low speed.

 

[George_R]

DTCs or ban?

 

[gloverman]

Is the air flow meter plugged in correctly? Also double check all the coil packs are plugged in correctly too and no wires are damaged.

 

[melvinmelvin]

Right,

thanks for feedback.

Yes, it worked very smoothly before the fixes.

Will recheck the colors on the igniter wires.
as well as the general wiring/plugging referred to above

Yes,
next on the to do list is opening up and re-check the timing belt

I changed the oil pump because I was not happy with the oil pressure.
I have a fairly big oil cooler above the engine with rather long and sizeable hoses,
maybe that contributes towards lowering the pressure.
Bought a pump from some kind of speed shop in the US, they take the
original Toyota oil pump and machine it somewhat to enhance oil flow
and oil pressure.

 

[melvinmelvin]

Re fuel pump:
I have an external Merc Benz compatible fuel pump.
It slows down a wee bit when it meets pressure, for example pumping while
the engine is not running.
In general I think the pump speed is pretty constant.

 

[Zuffen]

Melvin,

I've seen the porting of the UZ pump and it should increase the flow but no the pressure.

I had a stock engine that ran (what I call) low oil pressure at idle but very good oil pressure once it got to 1,000rpm.

Never seemed to bother it and it was running well when I sold it and probably still is 8 years later.

 

[melvinmelvin]

Melvin,

I've seen the porting of the UZ pump and it should increase the flow but no the pressure.

I had a stock engine that ran (what I call) low oil pressure at idle but very good oil pressure once it got to 1,000rpm.

Never seemed to bother it and it was running well when I sold it and probably still is 8 years later.

If the 3 seconds the engine is running is anything to judge by
the increase in the oil pressure is HUGE.

 

[melvinmelvin]

Assuming the engine ran well before the oil pump change it should run well now unless something has gone back together incorrectly,

I suspect the timing belt has been installed incorrectly. Check the timing marks all line up. As your mechanic did it I'd have him double check it.

One question; why was the oil pump replaced? They seem to last forever.

Pin 4 on the igniter is the tacho feed and pin 2 where you're getting your tacho feed goes to the ecu at pin 67.

I don't believe pins 2 & 3 have the same coloured wires.

Make sure you're looking at the pins in the right order.

On the run for 3 seconds and stop it sounds a little like it's running on the cold start valve or the fuel pump high speed circuit and dying when the fuel pump drops back to low speed.

Re tacho feed,
would you recommend that I change from pin 2 to pin 4,
or doesn't it matter?

Checked the colors on the 5-wire igniter this morning,
they are both red/black.
However, it looks and feels like the leftmost red/black is thinner/slimmer
than the rightmost one. Maybe the wire has been changed.

The 4-wire one is; (from left to right)
yellow/black yellow red/black (empty) black

 

[melvinmelvin]

Waiting for my mech. to finish another job before we can open up and check the timing.

Thats a part of the engine I have never seen.

Are the cogs etc well marked and it is "easy" to make a correct installation of the belt?

 

[George_R]

On a vvt 1UZ , original belt has 3 marks and is extremely easy to get aligned properly. I assume non vvt is the same story

 

[melvinmelvin]

*****

opened up and checked the timing belt yesterday.
My guy had mixed up left and right.
(you may not believe it but lots and lots of people in Thailand do not know
the difference between left and right, and those who do constantly mix up
left and right, that is just part of life here)

Anyway, after having re-installed the belt (presumably correct) the result is pretty much the same, some or all cylinders fire, cannot rev the engine, stops after 3 seconds.

If anything is different from the first time it is that with the belt wrongly installed,
the cylinders fired immediately,
now it takes a second or two before they fire.

I am leaning towards buying a new (2nd hand) engine.
There are some very good professional Toyota mechanics and electricians around,
a couple of days with one of those is more than halfway to a new engine.

 

[melvinmelvin]

A question re 1UZ and firing sequence.

In a booklet I printed off internet a couple of years back it says that
the cylinders are numbered 1-3-5-7 (left bank and 1 up front)
and 2-4-6-8 (right bank and 2 up front).

And the firing sequence is: 1-8-4-3-6-5-7-2.

Is this correct? If not, what is the right numbering and firing sequence?

 

[melvinmelvin]

Re possible new engine:

I have one particular engine in mind.
It looks very well maintained and is totally clean all over and is cheap.

However it has a massive number of wires going from the ECU bunch of wires
to the gearbox.
Can the plug/plugs on the gearbox just be unplugged and sealed in plastic
to protect them from rain and then just be forgotten about?
Or is there essential info flowing from the gearbox to the ECU that has to be hacked
in some way when the gearbox is removed?


(The most common for 1UZ in boats here is to remove the Toyota gearbox
and flywheel housing.
Then fit a flywheel housing and manual clutch from an Isuzu CBD engine.
And then fit a 4-gear Mazda gearbox from a small Mazda truck.)

 

[George_R]

better strip the loom off its plastic wrapping and delete the tranny wires completely. You will also ensure the loom does not have hidden problems.

Without auto transmission, factory ECU outputs a number of error codes but performs almost as fine as with one. Don't worry

 

[melvinmelvin]

Just checking my understanding of timing belt alignment:

The white arrows on the belt should point forward?

The alignment mark for each camshaft is the small linear dent in the plastic
cover behind the pulley?



The pulley on the crankshaft has a clear mark/cut
to align with the 0 on the plate behind it.
I have problems spotting similar marks on the cam pulleys.

 

[extractors]

Your firing order is correct.

Check dizy rotors to make sure they have been installed correctly, no broken rotor buttons etc.

Obviously triple check leads to plug arrangement, easy to muck that up with firing order.

Timing marks per cam belt, you are correct as above. Don't forget crankshaft drive sprocket has to be at TDC too.

Check plugs to coil packs, continuity test if suspicious. There is also a test for the coils if you care to look.

Usually if ignitor fails, it won't even kick over at all.

Does sound like timing is out somwhere

 

[gloverman]

We do have a tutorial section http://www.lextreme.com/tech_maintenance.html

 

[extractors]

Just realised this is for a vvti, so ignore my post above, have never worked on one.

 

[melvinmelvin]

Right,
thanks for feedback.

Seems I ought to open up and check the belt again.

The distr. rotors; aligns with / points to linear dent in the plastic?