Mark2 D4D - Sluggish and very poor MPG

[dawsieboy84]

Hi All

Got a Rav4 my wife loves and treats like an old grandparent so it is a well loved and looked after car! Recent oil change new Battery and SCV replacements! 

EGR nice and clean and to my knowledge no other issues except....

The car does feel sluggish like driving with handbrake on, all brakes checked and non binding, it just doesn't feel free!?! also our MPG has gone from 40 ish to early 30s with same journeys and driving?!

Any advice much appreciated! 

[Ant-Rav]

Just changed the mass air flow sensor that sit's on top of the air filter on the wife's much loved Rav, as it was very sluggish I think fuel economy was down, she said so anyway. Mechanic put car on computer and said air flow sensor was not right. Changed it and car immediately drove perfectly, knew as soon as I started it and revved it , that was the problem, worth trying but putting the car on a computer wud tell u.

[dawsieboy84]

it has a new Bosch MAF as well forgot to mention and new plugs! 

I was worried it may be a fuel pressure issue as is can be difficult (8-10 cranks) to start sometimes? 

[Ant-Rav]

Wonder cud it be an injector problem, they do sometimes give bother on these car's. i'm not sure,

[dawsieboy84]

37 minutes ago, Ant-Rav said:

Wonder cud it be an injector problem, they do sometimes give bother on these car's. i'm not sure,

did the old listen through a screw driver check and they are all ticking away! plus gallons of cleaner through the system! 

[Ant-Rav]

Aye, have heard bout specific test for the spray coming from an injector. But may not be injector problem, somebody will be along here soon to give their opinion i'm sure. Good luck.

[Byzii]

Hey,

What was the reason for replacing SCV valves? As far as I know those aren't on a scheduled maintenance cycle so should only be replaced when going bad.

Was everything working properly before your recent service? Because there are rarely coincidences when working with these things.

Was the MAF bought new? From where? Do you have an OBD scanner to check how much air it detects?

What about the air filter? What about air hoses, could be that some connection isn't tight enough after MAF replacement?

Was EGR cleaned out during this recent service? Who did it?

And what about the long cranking, was it like that before?

 

I'd recommend finding someone with a Toyota diagnostic computer to go through all values to see if everything works as it should. A few tests through the software should show any issues because again — coincidences are very rare.

 

[dawsieboy84]

bare with me here.... 

SCV changes due to hesitation under load which fixed it. Car has always had this issue since purchase about a year ago. last MOT sailed through 6 months ago.

Brand new MAF. I have a scanner but only to read codes. Toyota did a dyno and said no issues coming up but it did not even flag the SCV issues which were clearly broke.

all hoses fine and cranking has always been. Will try to get a video up.

Weird thing is when it has been super hot outside the car does smell very oily hot but no major leaks and engine bay clean.

The wife has driven it and after turning off after five minutes the car won't start. Never happens to me though 😀

[dawsieboy84]

here is a video of the car starting? I may be wrong but it should feel stronger especially with a new Battery!?

[dawsieboy84]

So an update....

Changed the fuel filter last night as ECC had a 70% sale and it drives like a brand new car. Had a few jolts but once it relearnt the fuel flow etc it has been smoother and quieter plus much more responsive. MPG has also gone up by about 6-8 MPG!!

[Colourd]

Thats good news, glad it was a simple fix