1UZ-FE starting problem for the electrical Guru's

["Z" UTE]

Hi guys, I have a Celsioir giving the owner some headaches.

1st start of the day is a bitch, coughs stumbles and eventually attains a stable idle.

Any other start during the day, when warm, is really good.

Throttle body, and Idle air control valve cleaned.

New plugs, leads, and battery.

There is no cold start injector on this engine, and it would seem the ECU batch fires the injectors for cold start. I really was hoping to find a blocked cold start injector. If the ECU is trying to get a reading from a failed temp sender, could that be the problem?

Soarer Central guys talk a lot about leaking capacitors on the ECU board, what are your opinions?

So has anyone got any idea, what the hell is happening. I am open to any worthwhile suggestions, thanks in advance Chuck.

[CrUZida]

I gather this is a 96-97 UCF20 Celsior?

My 1990 UZZ30 motor/ecu does something similar too.
But some mornings its perfect, some not so perfect.

I've cleaned/checked everything, the TPS is in IDL, etc etc.
The only thing I haven't done is rebuilt the ISCV.
Thats next on the list.

Leaking caps is a possibility, but I'd rule it out if its a 96-97 car, purely because its too new.
The older ones (pre 1994) are getting quite common with leaking caps though.

["Z" UTE]

CrUZida, thanks for the reply. Should have mentioned, the car is a UCF11 1990 model, only got 87,000k's on it. But yes, I was leaning towards the ECU.

The problem is evident first cold start any time, everyday. That was why I also thought about a temp sensor. But it could be the ECU that is not reading the sensor. Thinking about it, it would appear that the problem is related to the cold start circuit.

cheers Chuck.

[EldarO]

if its built anything like the 4AGE ecu, you should be able to open it up carefully and have a gander...?

or is it some weird, sealed, shrinkwrapped, doohickey?

Eldar.O.

[joecoolmk2]

i just pulled my plenum off my 1uz, and found what i thought WAS a cold start injector, it has a fuel line going to it....

[CrUZida]

1990-1995 HAS a cold start injector.

As point out by Joe, its underneath the upper intake plenum.

["Z" UTE]

Thanks for that guys. Guess I had better have a "closer look" at the fuel system. Just that I did not remember there being a cold start injector, when I pulled the last set of 1UZ injectors for cleaning. Tis a pain in many parts of the body, when you start to get older, memory fades, functions disfunction!!!!!!


cheers Chuck.

[joecoolmk2]

Thanks for that guys. Guess I had better have a "closer look" at the fuel system. Just that I did not remember there being a cold start injector, when I pulled the last set of 1UZ injectors for cleaning. Tis a pain in many parts of the body, when you start to get older, memory fades, functions disfunction!!!!!!


cheers Chuck.

it's tucked right up under the plenum, if you look down the throttle body there'll be a pipe that comes up from the bottom.

good luck mate.

["Z" UTE]

joecoolmk2, thanks for the info. Found the bastard, plenum removed, will check operation tomorrow. When I removed the banjo bolt, there was something that looked like melted plastic, blocking the fuel inlet to the injector!!! Will hook it up to the Seca tommorrow, and check the electrical operation. Or I could wait till monday, and put it through a clean and test cycle on the injector cleaner.

cheers Chuck.

[The Witzl]

Guys - i can almost GUARANTEE it's the ISCV.....

my crown demonstrated this EXACT problem, especially on cold mornings..
.. it would take a moment to start, sometimes a bit of throttle was needed, and when it started it would idle at like 200rpm or something stupidly low for a second or two..
... and then it just ROARED into life and would idle up at it's normal cold idle speed (1400rpm and stepped lower).

How did i know it was the ISCV?
I unplugged it one morning and it started with the same bastard low idle.... but it never "roared" up to it's cold idle speed - it just stayed stupidly low (and slowly increased as the engine warmed up)


STEP 1 - remove ISCV
STEP 2 - clean the bastard out!
STEP 3 - refit
STEP 4 - ????
STEP 5 - profit.

[The Witzl]

P.S. the cold start injector only exists for uber sub-zero temperature starts.

Have you ever seen what the CSI squirts? It's like a massive spew of fuel, like a tap opening rather than an injector spraying fuel...

On all my conversions i've never hooked up the CSI, and i've never had a problem starting - even with trips to the snow!

[1200det]

My Crown also did the same thing and the bearings were seized inside the ISCV , after cleaning and lubricating the bearings.

No-more cold start issues.



.

Guys - i can almost GUARANTEE it's the ISCV.....

my crown demonstrated this EXACT problem, especially on cold mornings..
.. it would take a moment to start, sometimes a bit of throttle was needed, and when it started it would idle at like 200rpm or something stupidly low for a second or two..
... and then it just ROARED into life and would idle up at it's normal cold idle speed (1400rpm and stepped lower).

How did i know it was the ISCV?
I unplugged it one morning and it started with the same bastard low idle.... but it never "roared" up to it's cold idle speed - it just stayed stupidly low (and slowly increased as the engine warmed up)


STEP 1 - remove ISCV
STEP 2 - clean the bastard out!
STEP 3 - refit
STEP 4 - ????
STEP 5 - profit.

["Z" UTE]

OK guys, thanks for all the input. The injector was not the problem. Cleaned and tested on the injector cleaner, great pattern from both nozzles.


ISCV/IACV will be removed and cleaned tomorrow!!!

cheers Chuck

["Z" UTE]

Ok, ISCV removed , bearings look as though they have recently been replaced, smooth, free, and fast.

Gave the valve a general clean and lube, re-fitted valve, started, and idled up, but was a little hesitant, ie stumbled to get to idle.

Will try a spare ISCV tomorrow.

cheers Chuck.

[1200det]

Chuck

Keep us updated as mine also does the same thing and i just assumed it would be the ISCV and had just been lazy in cleaning it etc , Looks as though it may not be the ISCV.


.

["Z" UTE]

Well, I checked the resistance across the various pins, on both ISCV's. Both showing up as correct by the LS400 workshop manual. So that sorta blows the ISCV theory on this one.

The next check will be at the ECU pins.(mumblefartmumble)

Will keep you updated, as things get crossed off the list.

cheers Chuck.

[1200det]

Chuck

Any luck !!!

Ive found with mine even in the FROST this morning if i give the key one quick hit without starting the vehicle and then hit it again it starts perfectly......

Sounds like a fuel pressure thing


.

["Z" UTE]

1200det, yes mate, if the Celsior uses a circuit opening relay like most other Toyotas, then that makes a lot of sense. The ECU has to see a rotational signal from the engine before it will turn the fuel pump on. Should be able to test the fuel pump by jumping FP and E1 in the diagnosis connector. I wonder if the Celsior has a dual voltage pump and fuel pump controller like the Soarer's?


cheers Chuck.

[CrUZida]

The ECU has to see a rotational signal from the engine before it will turn the fuel pump on.

Fuel Pump also turned on with START

[camrygt?]

EFI temp sensor maybe? I have had one on a mitsubishi with about a 2K resistance when cold, few hundred ohms when hot. It was hard to start and ran badly until it warm up a bit.

easy enough to check.. I put a 1 k resistor in series and it started and ran perfect when cold.

I think someone had swapped the sensor before with one from a different type of engine