intermitant lack of power/flat spot

[kevinf]

Hi all

I have a 2003 rav4.2 d4d approx. 110k mileage which as recently developed a intermittent flat spot,  car starts ok and normally as plenty of power ,then losses power  normally in 2nd gear when accelerating power normally returns and car continues to drive normally, occasionally car will lose power in 5th gear and engine warning light comes on. stopping engine, switching ignition off normally clears the fault. 

I have managed to borrow a snap-on code reader, first time I read the codes I got various non related codes, I had tried to disconnect things like MAF and MAP sensors so I cleared the codes, then retested, no fault codes, I then drive the car with the code reader connected and monitored the fuel rail pressure I experienced the fault several times and every time the fuel rail pressure  dropped to 290 bar, but no engine warning light and no fault codes,  finally after a couple of days the warning light came on again, when read fault code P1228 came up ! having read previous topics referring to scv valves, before jumping in and replacing them I do have another issue recently I noticed that the fuel tank developed a damp patch when full, so a new fuel tank is  required I am wondering could it possibly  be rust in side the fuel tank intermittently blocking  the low pressure pump, could this cause similar symptoms to the SCV valves,  can I get the pump out to check with out removing the tank? 

just trying to make a informed decision before I start throwing money at the car, potentially looking at replacing fuel tank, low pressure pump and scv,s

thanks 

[gjnorthall]

Your description certainly points to SCV problems. There is no low pressure fuel pump on this car - the fuel  is sucked by the HP pump. Check the fuel pipes for signs of leakage since this can cause air ingress. I suspect that rust blockage isn’t an issue in this case.

With respect to some fault codes - a code isn’t always flagged up when a fault arises - a pending code is stored and a fault code is only flagged after a number of recurrences.

[Gerg]

Hi,

I have seen that on some other makes of diesels the fuel filter causes a range of problems if overlooked, has yours been changed recently, or to schedule?

[gjnorthall]

It’s no less a problem on Rav’s. Infact, unless you’re confident about the filter, it should be the first thing you change in your quest to cure bad starting, hesitation etc.

[dawsieboy84]

I have just spent around £600 trying to sort this issue! I have changed MAP, MAF, SCV x 2 a full service, all of it!

Before you spend any money  would suggest trying this....

Test the Injectors, this can be done with a screwdriver and listening for clicking (plenty of Youtube videos to show you) if all are clicking then get under the back seat and remove the intank fuel sender (very easy job again Youtube) on this is a strainer type filter which gets clogged up if someone has been running c*&p diesel or even chip fat! Give the sender and the strainer a good soaking in carb cleaner.

There are two ways to then check if the injectors are blocked, either pull out and turn the engine over and see how they splatter onto a sheet of paper (again Youtube) or fill the tank with BP ultimate and take it for a really good drive, the injectors will open and close depending on load so if you feel it boggin down bury your foot and bear with it.... it will be like trying to blow a golf ball down a hose pipe but as the pressure builds it should blow any dirt out.... take it through the gears and give some beans in all gears up hills and on flats keep going they will free up!

eventually the car will just drive like a brand new one!

I did this last night after loads of time wasted..... my 74 year old Dad (ex engineer) always maintained D4Ds are notorious for blocked injectors! 

[dawsieboy84]

to add to this the bad starting is apparently a known fault on the RAVS MK2 D4D, the starter is a 1.4kw which as they get old just lose enough power to make it harder to start, its worse in the summer months when the car needs a bit more of a push and when the engine is hot, it will just crank and crank....

answer is a modified 2.2kw starter, you can buy them for around £89 and is an easy change with a Haynes manual. Failing that a local indy can do it in under an hour!

[kevinf]

Hi all

thanks for your input !

just to confirm the fuel filter was the first thing I changed with a good quality one, starting is ok so don't suspect the fuel pipes are drawing air but will check them any way

I think the next step will be to get the sender unit out, but if it does turn out to be the SCV's any recommendations of where to get them from ?

thanks

[dawsieboy84]

I  bought mine from eBay £150 ish for OEM from Japan.

Test them with a multi meter first as this is everyone go to issue, I had mine checked as I know the garage who did it and luckily they had not thrown them out.... they worked fine after everyone told me that was the problem so £150 wasted.