Intake Manifold Gasket Leak ? Toyota Prius 2010

Thank you very much for your help.But this doesnt show how to discharge fuel system pressure.Is there any valve or do I need to take out EFI relay while car is working ?

 

In the repair manual section @Mendel Leisk linked, disconnecting the 12v is the first step.

Then when removing the pipes and injectors, you'll have to drain it out. But the pump will not pressure it back up. I would do this while the engine had sat to avoid any flammable gas getting on a hot surface.

I get the P0171 code intermittently, and the next time I was planning on removing the egr system was at ~200 k miles. Looks like the to do list got just a bit longer.

Take pictures and keep us posted .

 

Here's something on relieving fuel system pressure. It's unfortunately got mention of "SST" (Special Service Tool), and talks about not reusing this and that, but maybe there are work arounds.

 

I've used the disable-fuel-pump-and-wait-for-engine-to-die method, and it works, but the engine dies with such drawn-out operatic convulsions that I start anthropomorphizing it and wishing I could beg for forgiveness.

Triggering one injector a few brief times with an ordinary 9 volt battery while the car is off will also let off the fuel line pressure. It will inject some fuel into the intake port, but you'll be working on stuff long enough anyway that there won't be any trouble starting the car by the time it's all back together.

It doesn't take much release of fuel to relieve the pressure. There's no expanding accumulator anywhere like there is in the brake system, just the pressure of some liquid in a skinny line.

The suggestion to use a 9 volt battery rather than 12 volts came from Rich at Cruzin Performance, who knows his injectors. It's enough to open them, while less likely to overheat them (a concern, as they are built to withstand only very short pulses in normal operation). I'd still do brief touches of the 9 volt, even, rather than holding it open for any length of time.

-Chap

 

How to connect the 9 volt battery? A particular pin in the fuel injector connector, and ground?

That first paragraph is hilarious, btw.

 

The connector on the injector itself has just two pins, which is just the number you need.

I was probably traumatized at a tender age by Terrel Miedaner's Mark III Beast.

-Chap

 

Very nice info.Thank you very much.

 

Hello everyone, I am going through the exact thing and would like to post about it in case anyone else has the same problems.

I have a 2011 3rd Gen Prius with 177,000 miles. Code P0171 came on and so far I have done the following repairs:

-Replaced MAF
-Cleaned intake manifold and throttle body
-Replaced Manifold gasket.
- Replaced Sparkplugs with Denso sparkplugs
-Replaced upstream o2 sensor with Denso sensor
-Replaced 12v batter (it would give me check hybrid system) message some times and was a bad battery

Next thing on the list is to clean the injectors and if check fuel pump if that doesn't do it.

I will keep you posted.