4.2 D4d Scv Valve Replacement

[gjnorthall]

I think the valve in question - circled yellow is called "valve assembly - vacuum switching" in the parts catalogue. If the fuel filter housing plunger doesn't remain firm, then air is getting into the system. This is a common problem which results in poor starting and I'd sort this before changing the starter motor. Try pumping the plunger if the car doesn't start straight away. There is either an air leak in somewhere back to the tank or the non-return valve in the filter head is faulty. In the case of an air leak - fuel will leak out when the car stands - look for evidence of a wet area on fuel lines etc.

[dawsieboy84]

1 hour ago, gjnorthall said:

I think the valve in question - circled yellow is called "valve assembly - vacuum switching" in the parts catalogue. If the fuel filter housing plunger doesn't remain firm, then air is getting into the system. This is a common problem which results in poor starting and I'd sort this before changing the starter motor. Try pumping the plunger if the car doesn't start straight away. There is either an air leak in somewhere back to the tank or the non-return valve in the filter head is faulty. In the case of an air leak - fuel will leak out when the car stands - look for evidence of a wet area on fuel lines etc.

had a quick look but no immediate evidence, my suspicion has always been fuel pressure but it only does it when it has been driven for a while and gets hot? cold starts are fine....

[dawsieboy84]

is there a way to change the non return valve in the filter head or is it a case of replacing the whole part? 

[gjnorthall]

Toyota only supply the full filter head. I've heard of owners of various vehicles installing a separate inline NRV in the fuel line.

[dawsieboy84]

On 10/15/2018 at 2:16 PM, dawsieboy84 said:

had a quick look but no immediate evidence, my suspicion has always been fuel pressure but it only does it when it has been driven for a while and gets hot? cold starts are fine....

dont suppose you know which side is best to fit one to? pump side or tank side of the fuel filter?

 

[gjnorthall]

It shouldn’t make much difference where the valve is situated - it’s more to do with the design of the valve. A simple ball or flap type  valve would work better in a vertical position. Use a metal body valve not a plastic type.

[dawsieboy84]

amazing!! 

have ordered some bits off eBay and will give it a go the weekend... whilst doing the pads and discs!!

great help! 

[Craxo]

Hi, I have a 2003 Rav4 D-4D and my problem started about 3 months ago when I noticed some slight hesitation at about 3000 RPM. I checked the EGR which was moving freely, I checked the turbo vacuum, cleaned the MAF with electronics spray and disconnected to make sure to get the CEL, changed the airfilter and not until some days later when I changed the fuel filter the car started running as normal. Now one week later I got the same issue, but this time the CEL came on and gave me a code 78 - Fuel Pump Control signal. I have read that high fuel pressure may be the cause. I'm on the verge of ordering some SCV and would appreciate some input if I'm on the right track. BTW Great little write up Rupert, will potentially follow it!

Thanks in advance.

-Fredrik

[Craxo]

On 11/8/2019 at 12:47 AM, Craxo said:

Hi, I have a 2003 Rav4 D-4D and my problem started about 3 months ago when I noticed some slight hesitation at about 3000 RPM. I checked the EGR which was moving freely, I checked the turbo vacuum, cleaned the MAF with electronics spray and disconnected to make sure to get the CEL, changed the airfilter and not until some days later when I changed the fuel filter the car started running as normal. Now one week later I got the same issue, but this time the CEL came on and gave me a code 78 - Fuel Pump Control signal. I have read that high fuel pressure may be the cause. I'm on the verge of ordering some SCV and would appreciate some input if I'm on the right track. BTW Great little write up Rupert, will potentially follow it!

Thanks in advance.

-Fredrik

I finally had some time with the car. I only got to measure the resistance of the valves, the red was 6 ohm and the green was 4 ohm @ 7 degrees celsius. I completely forgot to check for continuity...

[Craxo]

Alrighty, I found a scrapped Rav4 and got the SCV and the MAF for cheap, and it was in fact the SCV which was at fault. The swap took me under 30 mins and now it runs smooth as ever, and has been for weeks.

[Marcos Henry]

Hello to all, 

Is this the same as for a 2001 model Toyota RAV4 D4D, diesel 2.0L?

 

[Peter perfect]

Hi, could anyone help. Im trying to locate the fuel temp sensor, is it on the fuel pump?