UZZ31 1UZ won't fire. What have I missed?

[cuh8er]

Hi, I have a 1UZ wired into a landcruiser and it won't kick over. Just curious if there is any glaring problems with what I have wired before I go pull my hair out faultfinding.

Some background.
1. I have searched these forums for over 2 hours to try to find my mistake(s).
2. I have a ***220 ECU. 40/40/40 pin.
3. I have hard wired the fuel pumps in temporarily to a switch. Will change this later when the engine is running.
4. Engine has an UNCUT loom, so i'm assuming all the sensors etc on the engine are correct as they're as per factory.

Ok, this is what I have done so far.
* +12V wired to pin E9-33 (BATT)
* Pin E9-24 (M-REL) drives the Main EFI Relay.
* E9-31 (+B) and E9-32 (+B1) both get 12volts when the Main EFI Relay is switched.
* Main EFI Relay appears to be working fine.
* Pin E10-4 (E11) is grounded.
* Pin E10-65 (E2) is grounded.
* Pin E10-79 (E02) is grounded.
* Pin E10-80 (E01) is grounded.
* Pin E10-77 (STA) gets a 12volt input from starter relay when the engine is cranking.
* Pin E9-1 (IGSW) gets a switched 12volts from the ignition switch.

Do I need to do anything with the Neutral Start Switch?
Any help is much appreciated and thanks for reading....
Cheers

EDIT : I have a hydraulic fan on this engine, but my ECU part number ends in 220
This tells me it's a UZZ31 ECU, but I just read that the UZZ31's wern't fitted with a hydraulic fan. Is it possible I have the wrong ECU for this engine?

 

[Zuffen]

Have you checked you have fuel pressre? I once tried to start mine with the pump wired in reverse.

Same for spark. If the igniters aren't grounded you won't have spark.

Fuel injectors could be gummed up.

If you have fuel pressure (high pressure pump not a carby pump) try tapping the injectors (better still take them out and have them cleaned) as this can get them started.

 

[cuh8er]

Cheers Rod,
Any help is good help at this point.
I have pressure and have checked the pump (brand new Bosch 044).
I thought the igniters were internally grounded through the loom somewhere....?
I'll ground them now just in case.

 

[gloverman]

Common mistake - the ignitors have to have their bodies earthed. No earth in the loom to them. Cheers

 

[Cobra]

Ignitor casing must be earthed to the chassis.

How long has it been since the motor was started? If the injectors have been sitting for a while they will freeze up. Try gently tapping them to dislodge any blockage.

 

[cuh8er]

Cheers guys,
I have now run a dedicated ground to both the igniters and still no joy.

Motor has been sitting for around 2 years i'd say. I have tryed tapping the fuel rail above the injectors in an effort to dislodge any crud buildup, but still nothing.

My understanding is the injectors do not fire until the engine is running. The cold start injector kicks the engine over and then the others take over.

I would've thought it would have behaved differently even with a blocked injector or two.

I have now also checked power to the coils, igniters and injectors. All ok.

 

[Cobra]

Do you have spark at the plugs?

 

[cuh8er]

Cobra- Yes mate, plugs are sparking away nicely.

 

[cuh8er]

Ok, after all that the cold start injector wasn't plugged in properly. It's always the simple things isn't it.

The engine now kicks over, and fires (bloody loud with no exhaust on it, just the front pipes), but it won't actually run.

It fires under it's own steam for a few RPM, but then dies.
The air flow meter is bolted up so i'm not too sure what the problem is now!

Help again!

 

[cuh8er]

Ok i've been on this all day and I can't figure it out.
When the ignition switch is on, I have 12v on BOTH injector pins, is this normal? Doesn't make sense to me....

Really need to sort this....
Thanks

 

[Zuffen]

You would have 12 volts on both pins when the injector is firing.

As it fires but doesn't continue to run I'd suspect a fuel problem.

As your pump is hotwired it should still be running all the time, check it is.

I had a simillar problem with my engine when it had the Toyota ECU. I traced it to the high/low speed fuel resistor (I had a Crown) not switching from high to low speed. What it would do is when the engine cranks the pump runs in high speed. Once started the pump drops to low speed until you call for more fuel with engine revs. Mine wouldn't send power to the low speed section and the pump stopped.

Double check the operation of the fuel pump.

 

[sideshow]

like some other person said

ill bet 1 million dollars yr injecotrs are blocked

get can of aero start if it runs longer by sprayig htis in throttlebody then its this prob

u need to get an old injecotr plug with very long wires

break away outside of plug so u only have the 2 middle pins

plug this into each injecotr at a time and put one wire to batt pos

then tap the other to ground

so your basically jump starting the injecotr do this untill u hear the injecoitr start clicking

tapping the fuel rail will only put dents in it hehehe

does jack ****

if it runs on cold start injecotr then stops then yr injecotrs are blocked
can take up to 30 mins of tapping to unstick

 

[Cobra]

I'd still be checking the operation of the injectors.

 

[sideshow]

id be checking the injectors just like sideshow and cobra said

sorry forgot to mention u said to chekc them



hehehehe

 

[milisakeracing]

Something simple that no one has mentioned yet.....check the codes the ECU is throwing. I had a laundry list of codes when getting to the point you're at in my project and it was extremely helpful to be able to go down the list and resolve each of the codes. Many of my issues ended up being caused by lack of grounding, doh!

 

[madmont]

Do you have 12 volts switched to the injectors?

 

[madmont]

I have blocked the fuel to my cold start injector and it starts ok.

 

[sideshow]

thats wrong

injecotrs should pulse when cranking

the cold start just injects extra fuel when cold

just think of this

when enigne is warm you dont need the cold start injecotr
so if orig injecotrs dont pulse until enigne starts well u will be cranking till the ducks come home

anyway getting enigne wired is piss easy

diagnoising **** is totally different ball game which i have found only afew are good at it

 

[cjsupra90]

Actually earlier engine with cold start injectors do initally fire off the cold start, sort of believe it or not... I just dealt with this about a month ago. It is temp dependent....

The situation was a 95 engine and harness but the ECU was a 92... The 95 SC's do not have a cold start injector but the 92's do... I could get the motor to start and run with starting fluid but wouldn't run without it. I put a noid light on one of the injectors and noticed that I would get one flash while cranking and that was it, so started checking things and couldn't find anything thing wrong anywhere so suspected a bad ECU. In sted of risking frying another ECU is it was a short somewhere that I miss, we put the suspected bad ecu into a friends 93 SC and it worked fine so we know the ECU wasn't bad... Had known about people saying that the engine fires on the cold start and not believing it, I realized then that the 95 did not have a cold start so I decided to try a little test. I put jumped the coolent temp sensor wiring at the sensor plug with a 470 ohm resistor and the engine fired up on its own, didn't run the greatest cause it was cold but the ECU thought that it was right at about operating temp.... Realized that the whole problem was cause of the lack of could start setup that the 92 needed. Got a 95 ECU and everything worked exactly as it should have....

What I dont understand with the way that the system works is how does it run just off of the cold start and when does it rely on regular injection.. Obviously at a certian temp, it no longer fires from the cold start cause of the way I got it to start on its own but I cant see the engine running on the could start until it hits a certian temp. I would think that maybe a certian amount of airflow would cause the system to change over to regular injection but dont think this is the case cause I started the car on starting spray and kept it running for several seconds a couple of times before starting to check things out....

 

[sideshow]

i cant see toyota doing somehting so silly relying on cold start injector

every bloody 1uz ive done ive never seen this and ive seen many 1uzs with no cold start injecotr connected and they still start 90% perfect
the cold start makes it start that 10% better

nearly all toyota ecus have a built in safety so it doesnt flood cylinders
now the ignitors send a signal back to the ecu saying yes we have fired the spark plugs so now u can fire the injectors
this is so if there is no spark the injectors will not keep pulsing and flood the cylinders

so basically u need spark before u get injection
but the ecu will pulse the injector once or twice right at the start of the crank to get engine to start and if it doesnt get a signal from the ignitor
after the 1 or 2 pulses of the injectors it then shuts the injectors down

now u have to realise the engine onloy needs few sensors to run
i dont know why people have this idea that evrything needs to be connectedc for it to just start

crank and cam and ignitors are prob the only thing u need just to start enigne
it might run fiunny but it should start

if the ecu relied on coolant temp and throttle and all the other minor sensors
then u will never get in limp mode the enigne will just turn off
thats y the ecu has limp mode features
this is so if the not so important sensors fail u can still drive home

there is no way anyhting can be temp related otherwise u will get problems

i might be wrong but in the 500 toyotas i have wired up i have never come across this

this is th ebest way to test injectors
go buy some bloody aerostart or any flammable spray in a can

crank engine whhile spraying flammabkle stuff down throttlebody
beware this can cause burns to your arm hairs if u get backfire
so take care now if the engine starts and half runs then the spark side of it is ok
if it wont start unless u spray **** down throttlebody then there is usually
afew things wrong
now alot of people do not think of the basics

so power to injecotrs is one prob but not common

stuck injecotrs this is the most common

no signal from ignitors to ecu to tell ecu to fire

fuel lines on backwards so this means fuel pressure is pushing into the press reg from the worng side and not filling the fuel rail
this is 2nd most common problem

now the signal form the ignitors can be afew different reasons y u would get no signal now i dont have 5 days to tell u them all so i guess some of u will have to go learn how it all works

but when i get cars in from other shops or customers that wont start
i check these first

then i might take afew hours to sort problem out but these are the best guides to where the problem is



especially if u thing u have wiring ok then these are the next things to check if it wont start