Intermittent Starting Issue - 2003 Rav4 Gx 5Dr 2.0 Vvti

[LeeADAB]

Update: 14/02....Since Feb 2nd.....All has been good since changing coil 2 out. Even on really damp mornings that I would have laid bets it would flutter, it started perfectly. Until this damp morning when the flutter returned. It seemed different this time though and fluttered as soon as i turned the ignition over.

[LeeADAB]

Hi all,

So back to my ongoing "intermittent" starting issue.

I have now Removed and Cleaned the throttle body and ICV. Throttle response seems much better and a lot smoother takeup when changing gears.

Both TB and ICV were quite carbon'd up and it was good to see them both spotless after.

This hasn't solved my starting issue though as it still does it. :( Fortunately it is getting a little more regular which may help with finding a solution.

It isn't dampness as it has happened a few times on dry days. It only seems to happen when the car has sat either overnight or not driven for a day. I parked up last night and haven't driven it all day today. This evening I started it up and it struggled to fire up again.

So does this sound like fuel delivery issue?

If fuel pump then wouldn't I have the problem more often and notice while driving?

The car runs so so well once started and throughout all aspects of acceleration/driving.

The fuel tank gas cap hisses when I undo it which is correct for a closed system i believe. If the fuel was running back to the tank then wouldn't a few IGN turn on/offs before starting prime the fuel ready?

Once started I have no issues all day no matter how many times it is stopped and started and starts positively each and every time.

A while ago I ran a bottle of STP injector cleaner through it which couldn't hurt to try.

Please HELP me still!!

[LeeADAB]

I must be getting closer to the culprit as it really struggled to start this morning. It must know I'm close!! I only heard the fuel pump prime once (buzzing sound for a couple of seconds). I tried switching the ignition from off to ON quite a few times. I presume the fuel pump should be heard every time?

So relay or complete pump? Any thoughts?

Cheers, Lee

[anchorman]

The fuel pump should run every time and the surplus goes back to the tank. There is usually a pressure relief valve on the fuel rail.

[LeeADAB]

Cheers Don. I do remember the couple of seconds of buzzing noise of the fuel pump priming each time I turn the key to on but it just doesn't do that at all today.

I've checked and swapped the efi and circuit opening relay with an identical fan relay to test those and neither have made the pump whirr!

I also checked the other fuses in the engine bay compartment but all those are ok.

Is there any more relays inside the car to check?

If the pump itself was faulty surely that would have a noticeable effect on driving - which there isn't. Or is the fuel pump just to prime and then the engine pulls through what it needs??

If it is working full time then surely that can't be at fault? I am ruling out the filter being blocked as that would definitely cause performance issues and not be only a problem after sitting.

[LeeADAB]

More testing this morning....fired up fine but definitely no fuel pump noise.

I have found that there is no ground connection on the 10a EFI 3 fuse. All the others have a permanent ground. I presume this should too? It receives 12v when ignition is in the on position.

I cant get the cream fuseboard out either. The 10mm bolt unscrews and it lifts up but won't come out to see the underside.

Does anyone know if this fuse should be grounded?

[anchorman]

Sometimes the ground is made when another circuit is made if you get what I mean. Not sure if I have the wiring diagrams for petrols but will have a look.

[LeeADAB]

Today I have checked continuity on all the relays in there.

All ok. Will need to check them with 12v too to be sure.

Checked ohm reading of crankshaft position sensor. That tested within the specified range

Need to test the camshaft position sensor tomorrow as earlier I tested the wrong item.

[LeeADAB]

Only other thing to mention is that I pulled off the rubber grommet to the fuel pump area under the passenger rear seat and with the engine running the fuel can be heard being drawn up and through the pipe.

Would that be the pump working happily or is that just the engine pulling it through?

Cheers, Lee

[LeeADAB]

Camshaft Position Sensor OHM reading within specified range, so will rule that out too.

If I lift the metal cover to get to the fuel pump connections what is the black goo that is holding it down. Do i just prise or carefully cut to separate the goo seal? I know there was a post a while back about them being rusted but mine isn't at all.

I will test that the electrical connector to the fuel pump is getting power when I turn the ignition on. If it does then I think it is a failed fuel pump. Still doesn't explain why the car has been running fine once started if that has failed.

Any more ideas for me to investigate/test?

Cheers,
Lee

[LeeADAB]

If it is the fuel pump and from what I have read should really last the lifetime of the car I don't see a problem getting a used pump.

Has anyone here changed a fuel pump on a 4.2 Rav4?

The filter looks like it can be changed as it has it's own part number ( 23217A / 23217-74021 ) so as long as the actual pump unit works all should be fine?

This is turning into my "Intermittent Starting issue" DIARY! Well there's been lots of views so someones reading this. :)

[anchorman]

Does it turn over fast enough when cold?

[LeeADAB]

No. Slower to turn over when cold in mornings and if its sat for a day without use.

Can't test power to pump until I manage to cleanly remove the metal access cover under seat. It seems well stuck down. :(

[LeeADAB]

Is there any other separate fuel pump relays I have missed?

[anchorman]

If the starter gets knack'd it will draw too much power. On a petrol you can get "coil robbing" where it deprives them of enough voltage for a good spark. It is obviously less of a problem when warm.

If you put a volt meter across the Battery and measure the voltage, it shouldn't drop below 9.6 when cranking.

[LeeADAB]

Will check batt voltage but that's fairly new. Before I even turn the key to start the fuel pump doesn't run like it used to though.

[anchorman]

Does it start any worse than it used to!!!

[LeeADAB]

Hi Don,

Definitely starts worse than it used to. :( And there definitely used to be a two second priming noise for the fuel pump.

I have attached two sound clips.....

Start with fuel pump not priming.mp3

Turn off and restarts Perfectly.mp3

Oh and I removed the relays and they have tested ok with 12v applied. :)

I can't find any reference to a fuel pump cut off switch either. If it had a hidden one of those maybe that had been activated going over a pothole etc?

[anchorman]

I think the ECU shuts the fuel supply off when there is a seatbelt actuation. The pump must run or it wouldn't start at all.

[LeeADAB]

You're right it must run once the engine is started but there must be something that is stopping the initial two second prime before turning the car over. I definitely know that used to happen. Key in....ignition to on position.....buzzzzzzzzz(2secs).....turn key and it starts right up. Bring back the buzzzzzzzzzzz and I think it will be problem solved!!!

I also read somewhere today that some maf's can create a ground connection to the open relay which in turn feeds the fuel pump. How can I test the maf sensor. I have the resistance specifications for the sensor but no info on what terminals to test on.

Cheers,Lee

[LeeADAB]

If the system is pressurised then it would run without the fuel pump working until the fuel runs out. I can only imagine that my system is holding pressure well and that is allowing me to continiue using the car for this long.

Only when it had sat for longer periods Overnight/all day, will it take a bit longer to start. If I leave it for just a few hours when going places it fires up fine when I restart.

I will try to remove the metal cover later and see if power is getting to the pump when I tune the key to ON.

The other thing I can try is to follow the steps for fuel pump replacement and de-pressurise the system. Release fuel cap.....Unplug connector to fuel pump....start car and run until engine dies.........??

The problem with that is I can then not start the car if the fuel pump is dead until iI get a replacemen!!!!

[LeeADAB]

The fuel pump lives!! I connected across the c/opn connection to bypass the relay. That sent 12v whizzing down to the fuel pump. Great to hear the pump at last. At least that works.

[Big Kev]

Wish ah could help here, Lee min, but only come in tae wish you all the best and hope you are on to a cure, as you have given new meaning to the expression "dog with a bone".........if ever cannae cure wife's car, I will park it ootside your gaff.

[anchorman]

If I can find a wiring diagram I will have a rummage.

OK found the engine manual but it is 7.5Mb. Pm your email address and I will try to send it. I am on dead early in the morning so bed now but if you send it I will try first thing.

[LeeADAB]

Cheers Big Kev!! You can probably tell I don't like to be beaten!! Well not by the car anyway!! ;)

Thanks very much again Don - PM sent!!

Lets hope we are on the home run now!! Who would have thought a car would run for so long without power to the fuel pump! My mpg is going to go down when I've fixed this?