2LTE Spill Control Valve (1 Viewer)

[kkriese]

With some help, I have (I think) found my problem; the 2lte on my prado has intermittently refused to start for months. I replaced the fuel filter, checked all lines, checking for air leaks. Then I installed clear hose to track down air. very small bubbles (tiny) very occasionally. When she starts, she starts and runs great.

I got some advice to check the fuel cut solenoid; according to Assie sites, on a 2LTE it's actually a spill control valve run by the ECU. I split the wires to the spill control valve so I could measure the voltage when starting. When the ignition was turned to "on" the voltage showed 4.5 volts and the engine started fine. That's how I believe it's supposed to work. Then I shut the engine and tried again and now the voltage spikes to 3, goes back to zero, and when I engage the starter the meter jumps to about 9.5 volts, and won't start.

So, my current thinking is that the ECU is not sending the proper voltage to the spill control valve in the "on" position and the valve is not opening.

I checked the ECU fault codes using the dianosis on the Surf Tech site; the engine light blinked a single blink repeatedly, so I believe this means "no faults".

Is my ECU toast?

I know people have had trouble with some of the other engine sensors giving the ECU bad information.

Any ideas would be great.

thanks,

kevin

 

[Radd Cruisers]

Test the computer - not that easy to do.

Finding a known good replacement... possible a challenge.

Replace the inj pump - relatively easy to do.

Hard to test voltage on a circuit that is loaded and you have no idea the effect of the load on the voltage. If the spill valve is faulty, replace the pump...

The 2LTE and all of its control systems are problematic.

In all fairness, carefully jack up the radiator cap and remove the LJ78 from underneath. Now, drive an HZJ77 under the lifted rad cap, carefully lower the cap into place. Problem solved. Better power, better economy, and you'll have this fabled thing called reliability...


~John

 

[toddm]

I know how the 1KZ-TE spill valve works, and I think the 2LTE is identical.

The spill valve gets power from the spill valve relay, which is controlled by the ECU. The spill valve gets its ground directly thru the ECU. It will be energized when the pump is injecting fuel to one of the cylinders, and it gets de-energized to stop the injection cycle. when it de-energizes it allows the spill valve to retract and open a passage which "spills" the remaining high pressure fuel back into the pump housing.

I doubt the spill valve will work intermittently. You should look at the circuit that feeds power to it in my opinion.

Don't try to measure the voltage across the spill valve. It changes too fast for a digital multimeter, you will need a oscilloscope for that. The spill valve is only operating when the engine is turning. I don't think it closes until the ECU gets enough data to find TDC and RPM. Once running the spill valve will open and close twice per engine revolution. at 1000 rpm thats just over 33 times a second.

You CAN check the supply voltage. You should hook your meter to a good ground on the engine block somewhere and just measure the 12VDC voltage supply to the relay and then from the relay to the spill valve.

a broken wire could also cause the intermittent operation, while checking the voltage, try wiggling the wires at the pump, ECU and relay and see if it changes anything.

 

[Ratpuke]

In all fairness, carefully jack up the radiator cap and remove the LJ78 from underneath. Now, drive an HZJ77 under the lifted rad cap, carefully lower the cap into place. Problem solved. Better power, better economy, and you'll have this fabled thing called reliability...


~John