1uz problems

[crownv8]

I have put a 1uz from a uzs131 into a 1976 Crown. It has been running great until last night. It cut out on the road. Sort of cut in and out a few times and then died. Then after a while it started again only to cut out a few minutes later.

When it runs it is perfect. No engine light flashing and the O/D light flashes because I am yet to connect the second speed sensor.

I guess my question is: Does anyone have any ideas?????

I have checked the wiring and relays and everything seems ok. I'm stumped???

The other thing is I tried to get engine codes and when I bridge TE1 and E1 all I get is the O/D light flashing.

When I got it to run again and as usual it was running smooth and sounded good. No check lights flashing. This time when it cut out I checked a few things. There is plenty of fuel. There is power to the ignitors. There is power to the computer, both battery + and the two ignition + wires. There is no spark. Nothing from either coil. So whatever it is must be common to both coils.

I'm wondering if the crank angle sensor could be a problem. What ever it is the second it happens the engine check light and the alternator lights come on. Even though the engine is still "winding down" the system thinks the engine is completely still.

Cheers,
Shane.

[CrUZida]

CEL and charge lights mean alternator not charging.

The CEL should also flash (along with the OD light) with TE1 and E1 connected.

Unplugging any of the crank/cam angle sensors should cause the motor to die instantly, but it should also throw a code.

A common fault is the wires to the drivers side cam angle sensor gets cut by the accessories belt.

[hot rods]

if that dont work ask Giant Tomato, he will know for sure. Rod

[crownv8]

Checked the wires and they're fine. But that is the symptoms I am having so I might check the sensor wires for continuity incase there is a break in one.

Does the 1uz have computer problems???

[CrUZida]

Only when it comes to cold starting.

[crownv8]

That's interesting then. It had been starting good hot or cold. Just recently it has been a pig to start cold. Sometimes seemed to over fuel it and I get a cloud of smoke sometimes seems to under fuel and takes a couple of cranks to start. Could this be connected??

[CrUZida]

It could very well be.

With a lot of Toyota ECU's of the late 80's, early 90's, they are now 'dying'.

What I mean by this is that the capacitors in them are beginning to degrade and leak.
All you need to do is pull the ecu apart, and change out the capacitors.
This has worked wonders for people in the past.

My one coughs for 3-5 seconds after cold startup, but is perfect after that.
Only started doing it a few months ago.

The only other possibility is that the cold start injector is leaking/blocked.

[The Witzl]

My one coughs for 3-5 seconds after cold startup, but is perfect after that.
Only started doing it a few months ago.

The only other possibility is that the cold start injector is leaking/blocked.

My UZS131 used to do the same. Cleaned the ISCV, and then it started like a dream every day.
Before that, the engine was starved for air when cranking cos the ISCV was sticky and not opening up fast enough.... the engine would start after a few seconds, barely idle for a few more seconds, and then the ISCV would finally open up and it would cold idle at the correct ~1500rpm or so.

Cold start injector would probably be better off left UNPLUGGED!! We dont live in a country that freezes engines.

[BeRad]

Reset the ecu and see if it pulls a code then, whilst i was playing around with my bros car it wouldnt throw a code, as soon as i removed the ecu relay for 30 seconds and tried again it came up with the code.

Good luck, if theres no spark there probly no fuel, suggesting something to do with the cas.

[crownv8]

I finally got the computer to give me a code. I started the car today and it ran until it warmed up and then stopped. I am getting code 13. I have searched and it seems to point toward crank angle sensor, wiring or ECU.

So I am off to try and find out which one it is.

Shane.

[crownv8]

I have checked the wiring and I have continuity from the crank sensor to the ecu. On both sensor wires. I put it all back together and it wouldn't start and now the computer is giving me code 12. That seems to be the same area as code 13.

Probably the cheapest thing to try first is the sensor. But it is looking more like the ecu has failed. :-(

Any help with this is greatly appreciated.

[CrUZida]

ECU failure would be rare.
Sensor failure is also very rare.

[The Witzl]

ECU failure would be rare.
Sensor failure is also very rare.

Quoted for truth.
99% of the time it is wiring/plugs/terminations.

Check signals are right, and check everything is aligned correctly... they can sometimes slip and stuff

[crownv8]

Thanks guys. I think I will run a new wire from the ecu down to the sensor and see what that does. If that fixes it I will be very happy. BTW can I check the output voltage from the ecu to the sensor? When the engine cuts out I usually have a fair deal of time to check stuff. If so what output voltage should I be looking for??

[CrUZida]

The sensor just produces a voltage spike as the crank toothed wheel goes past it.
You really need a CRO to see its actual output.

During its rest state its just seen as a resistor, a value of 160ohms rings a bell, but don't quote me on that.