Toyota yaris extended cranking time intermitent

Is it normal that the fuel pump don't start when ignition is ON and engine OFF,?
Is it normal that the fuel pump is activated (2, 3 second) after you shut the engine OFF?
With a Scan Tool I can activate the pump, I can here the relay and the pump being activated.
In an extend crank time the status Of the pump is OFF, then ON and the engine start.
Thank you

What's the fuel pressure when you are cranking? Is it to low to start?

I don't have a pressure gage, but in scan tool, the status is OFF while cranking until it start.
Don't have any issue while driving, I performed the test wide open throttle and the o2 goes rich.
the problem is intermittent .

Is that all that's not working when you get the extended crank? Or is it losing something else to? I'm not familiar enough with that system to know if that's normal. I would think that it's not. It could be that it's losing crank signal. If the computer isn't getting a crank signal then it's not going to turn the pump on. Or it could be something else entirely

dzof wrote: Is it normal that the fuel pump don't start when ignition is ON and engine OFF,?

No, that's actually somewhat typical of Toyota. Most I've seen do NOT use a key on fuel pump prime, they just start running the pump during cranking.

Is it normal that the fuel pump is activated (2, 3 second) after you shut the engine OFF?

Possibly? I haven't seen that, personally, but it may be normal.


It might be valuable to back up what the scan tool is saying with a test light on the fuel pump relay during the extended crank time. Not sure what year of Yaris this is, but I picked an '07 as an example:



Find this C/OPN relay, and connect your test light to the relay ground control pin I marked. Hook your test light up to B+ so that it lights when it finds a ground. Observe the light during normal cranking, and how quickly it comes on. Then watch it during your extended crank time, and see if it isn't getting lit as quickly.

If the test light lights normally, then the fuel pump control isn't an issue. If there's a lot of cranking before the test light illuminates, then we can go towards why the pump isn't getting commanded on correctly (possible cam/crank issue like bruce.oliver mentioned).

Yes that is all that's not working, I have an rpm signal while crancking,
thank you

Thank you for your response Tyler, like I said is intermitent sometime ones a days sometimes no extended crank for 2 days, sometimes 3 or 4 extended crank, I was lucky to recorded it on scan tool. I will perform the test light test Hope I am lucky again.

I put a gauge on the pump circuit, when I activate the pump I have 3 bar, as soon as a shut off the pump the pressure drop to 0 bar, so my pump can't hold the pressure, so I think this is why I have extended crank, Can the amount of fuel that stays in the rail cause the intermittent .

Oh yes definitely. Now your job is to work out where your pressure is dropping. There's a few place to check. The injectors, ( unlikely imo) or inside the tank. There's a check valve inside the pump that may be leaking or the regulator itself may have failed. The other thing I've seen on some intank filters which I'm quite sure yours will have is an o-ring won't seal properly or will roll over and will leak. Either on the top of the pump or where the filter meets the top part of the filter assembly.
Has the fuel gauge you have got a tap? One way of isolating the leak is to prime th system and quickly turn the tap off and see of the pressure still drops.

Thanks Matt.white,
so I connected the gauge directly to the pump the result was
prime: 2.5 bar
after 3 minute -> 2.3 bar
Then I connected the Injectors with a T pipe
Prime: 2.4 bar
after 3 minute -> 1,9 bar
I don't know If I can use simple math but
the pump lost 0.2 bar pressure in 3 minute
the injector and the pump lost 0.5 bar in 3 minute.
So I think I have leak in the pump and the injector.
Add to that I have a negative Lft -6 and Lft -4 at idling
I have white smoke in cold start. So I think I can confirm a leak injector and pump.
what do you think?

dzof wrote: Thanks Matt.white,
so I connected the gauge directly to the pump the result was
prime: 2.5 bar
after 3 minute -> 2.3 bar
Then I connected the Injectors with a T pipe
Prime: 2.4 bar
after 3 minute -> 1,9 bar
I don't know If I can use simple math but
the pump lost 0.2 bar pressure in 3 minute
the injector and the pump lost 0.5 bar in 3 minute.
So I think I have leak in the pump and the injector.
Add to that I have a negative Lft -6 and Lft -4 at idling
I have white smoke in cold start. So I think I can confirm a leak injector and pump.
what do you think?

For me, the easiest way to confirm a leaking injector would be to remove the fuel rail from the intake and leave the injectors installed in the rail. Prime the rail to full pressure (with the fuel line still connected to the rail), and place some tissue paper beneath each fuel injector nozzle. The one that's wet after 10 minutes or so is the issue.

Based on the pressure leak down rates you saw, I'd be inclined to go after an injector first, and recheck for a pump issue afterwards.

In a post on the previous page you mentioned the pressure dropping to 0. What Changed between your two tests or am I misreading it?

I don't see the pump issue as big enough to be a problem, but a leaky injector will cause an extended crank time because the fuel is going into the manifold.

Is the fuel pressure regulator on the fuel rail on this engine ?

in my first attempt i wanted to connect my gauge near the pump, but I couldn't, I didn't reconnect the pipe to pump very well.that's why it dropped to 0 when I did the test near the injector rail , I only noticed that after I submit in the forum. sorry about that.

thank you, I did the test and the four injectors are leaking

dzof wrote: thank you, I did the test and the four injectors are leaking

No joke! That's crazy, I'd have never expected all four to be leaking. :ohmy:

Let us know how the leak down test goes after replacing the injectors?

Oh well, at least you got it sorted. I obviously jumped to incorrect conclusions but I've seen a few toyotas with see in-tank filters leak from either a failed regulator or around a seal on the filter. Pretty common anyway.

Be sure to do the filter after the injector leak is rectified anyway.


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