1UZ Idle issues

[Kush]

Hi,

I've got a 1UZ in my hilux and recently after installing a long range fuel tank, the fuel rail has very intermittent fuel delivery. The ute drove fine for a day, and the the following day, it was running rough and would shut off at random times, which leaves it undrivable at this stage. I have pulled the fuel line off the rail and placed inside a bottle and only small amounts of fuel comes out.
Have triple checked all lines to see if they are on properly and not allowing an air leak. Have cleaned fuel filter and also taken the tank off again and cleaned it.
The fuel system setup works via a lift pump --> surge tank --> fuel pump

What else could I try to fix this?

Thanks!

[dumbass]

It's your new tank as that's the only thing u have changed
Te pickup is blocked or not long enough to reach the bottom
Maybe fill your tank right up and see what happens
I'm guessing it gets low fuel then your pickup is to short to pick up more fuel

[Kush]

I had filled the tank to roughly half and it was still starving for fuel. Had a look at the pickup line inside the tank when I cleaned it and it appears to be roughly ~10mm from the base of the tank and is clean..
Any other things I should look at?

[Stolic]

How's your surge tank set up? any pics?

[dnegative]

Coincidence that you have a bad pump?
Pull the lines off the rail, hotwire the pumps and see if it pisses out fuel?

[boxh34d]

If it isn't the pickup blocked, or a dead pump, could be the breather system not hooked up properly or blocked???
I've seen 2 cars now with blocked breather setups, they would run for a while until the vacuum built up, and stall, shunt carry on and then stop. Wouldn't run properly for love nor money, but when the owners went to put more fuel in, the tank would suck a heap of air in and run fine afterwards.

[Kush]

So the lack of fuel turned out to be a dodgy lift pump. Have replaced it with one from SuperCheap but want to install something that will last longer in the future (any recommendations?)

Another issue that I've been having for quite some time now is very spontaneous idle. Some days it will start up fine and idle at a little over 1000RPM, even when it's cold and some days it won't. The weather being hot or cold doesn't affect the way it idles as sometimes if it's really cold, it will idle fine and sometimes if it's really hot, it won't idle properly. Lately it's been idling from 500RPM up to 2500RPM on first start of the day. If the engine has been started and is still warm, then it idles fine.

Have read through some threads about the same issue and read that I should replace my ECU water temp sensor? I will be buying a new sensor coming week but is there anything else I can check?

Motor is from a 1992 1UZ UZZ30?

[George]

had similar issue with 92 LS400 engine. Turned out to be worn TPS, replaced it with another used unit and hadn't issues after that. Prior to replacing TPS I thought it could be stuck IAC valve.

In your case, water temp sensor could also be tricky. I don't know a way to test it without some effort (I use scanner or oscilloscope), rather prefer to replace on older engines.

[Kush]

had similar issue with 92 LS400 engine. Turned out to be worn TPS, replaced it with another used unit and hadn't issues after that. Prior to replacing TPS I thought it could be stuck IAC valve.

In your case, water temp sensor could also be tricky. I don't know a way to test it without some effort (I use scanner or oscilloscope), rather prefer to replace on older engines.

Yeah looking at just replacing with a brand new sensor. They are cheap enough now. How much is another TPS worth?

[George]

I took a used one from a rooted engine. There's always a couple of crap engines around for quick fixes. New tps must be around $50 usd

[Kush]

Sounds good. Will definitely be trying that sensor after I replace the water temp sensor. I started the 1UZ earlier in quite cool weather, and it only idled at around 500RPM then stalled after about 10 seconds..
Hoping it is only sensors that need changing

[Kush]

I replaced the water temp sensor with a brand new one from Toyota and that didn't change anything.. Car still idles really low on first start up and sometimes stalls aswell..
Any 1UZ gurus know what I should look for next?



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Engine has also developed a ticking noise during the last few days...

View My Video

[4th surf]

Now you have got the fuel lines on around the right way? If not it will still run but all sorts of fun and noises will be caused.

[dumbass]

if u think u have fuel pressure problem just go buy a 10 dollar plastic clearish fuel filter
fit it to the return line from engine to surge tank
the clearish ones u can see the fuel returning and this gives u a rough guide on how much flow u have on the return

instead of replacing parts just get multimeter and measure the tps wire and the coolant temp wire
also maybe there is a wiring issue as no backup battery power to ecu will affect yr idle motor settings
also how yr efi relay is wired can affect things too as if its not right yr idle motor wont reset when u turn engine off
most fo these problems are due to pisspoor wiring when the conversion gets done
its easy to get motor running but to do it nice and correct takes abit more effort

if u want to pay someone to fix it up bring it down to gold coast and ill fix it for u

[Kush]

Now you have got the fuel lines on around the right way? If not it will still run but all sorts of fun and noises will be caused.

I'm pretty sure it's right. Had a mobile mech check it and he said it was fine but I've attached a pic of the tank so maybe you can tell me if it's actually right or not