Car cracking but not starting

[Marc_lrfc]

I have a Toyota Corolla 2003 petrol 1.6
Problem started out side my home car didn't start straight away like it usually does but on 2nd attempt it started I then drove down to my local shop fine came out and car failed to start ! was just cranking over but not starting?
I then tried again 3/4 hours later car started! I drove 20 yards car just cut out and would not start again!
I then got the AA to come and have a look where they could not find the problem and there diagnostic computer would not connect to car? So I had car taken to my house as it was a Sunday!
I've since tested relay with a meter that seems fine but when I turn car over I don't feel the relay or hear it switching? So obviously fuel pump is not then getting power!
Any ideas on what I could try? 
Also 2 months ago engine management light came on but car was running fine and light went out a day later I'm not sure if this is related in anyway 
Thanks 

 

[Marc_lrfc]

Also the Rev counter does not jump or move at all when engine is turning over is this normal?

im sure I seen somewhere that even if car is not starting the needle should jump a bit when cranking over X 

[oldcodger]

Assume you mean the AA guy supected a fuel problem and hence you checking the fuel pump relay ?

From the diagrams I have seen there is no single fuse just  for the fuel pump.

The way the relay boxes are wired you cannot readily see if the relay contact is actually passing any current, so perhaps you might be better looking at the wiring connector to the fuel pump.

Have never tried ,but with the carpet up wonder if you can hear the pump working ?

NEEDLESS TO SAY, USE EXTREME CAUTION WHEN WORKING ON THE FUEL SYSTEM - AT YOUR OWN RISK

[Marc_lrfc]

Yeah and when AA guy was at side of road he could not hear the fuel pump either.

it was a rainy day day so while he was there it was a bit rushed!

ive since listed and can't hear nothing by pump,

ive texted relay with meter and its switching when I apply 12v but when I put it back on car and turn ignition it's not switching at all 😕

[oldcodger]

Its not an area I have worked on, but this is the dscription from the Haynes manual.

" the fuel pump will operate as long as th engine is cranking or running and the Control Module is receiving ignition reference pulses from the ign system.

if no pulses from the Ign ,then the CModule switches off the pump after 2-3 seconds "

The diagram below is the only one I can find a 2004 US model.

If you are sure the relay is not being turned on when you crank then if kind of suggest the Control Module or wiring/relay base is faulty.

Similary if the relay is begin turned on, is it actually passing power via its contacts, they could be worn out.

Think I would still like to see a volt test on the wiring connector ( disconnected ) from the fuel pump and  / or , if you can see another relay  the same, swap the relays to be sure its not that...

[Marc_lrfc]

Oh great thanks for that 😊👍🏼

The AA GUY did also suggest maybe

a faulty crank sensor? Can't find much info on them online or a diagram to find out exactly where that is on my car 

[oldcodger]

Learning myself here !  seems it could be that sensor ..

"Symptoms of a bad crank sensor can vary, from bucking and hesitation when accelerating to the engine cranking but not starting"

Trouble is its not cheap and needs a fair bit of work to get it out, the Haynes manual says the Alternator has to come out !

Several Ytubes on how to get at it.

 

[oldcodger]

Seems the relay for the fuel pump is under the dash ?  Have not gone under mine, but would be interested to know if its labelled clearly  ?

Looking at various online sources it is said to be labelled as "  C\OPN "  is that the one you checked ?

Before going to the trouble of replacing the crank sensor, which as far as I can see is not easy to test without a fequency meter /scope etc and a running engine, I would think its worth checking the fuel pump circuit a bit more.

If there are other indentical relays you could try swapping them over, plus as you have tested the relay and know which pins the coil is on, you could remove the relay and put your meter probes into the relay base coil  sockets and then switch on /crank to see if you get any voltage at all ?

Also worth checking the crank sensors plug and socket in case its just dirty / broken contacts, seems to be about 6" down from the actual sensor so might have gotten wet during the recent rains?

[Marc_lrfc]

Actually no it's not that relay I've checked? 

The EFI relay I've checked and does not seem to be switching when ignition turned? 

I have thought of that idea myself of taking relay out and putting meter across pins but have yet to try that 

[oldcodger]

Think this simplied diagram shows the whole fuel pump circuit quiet well and all the parts already mentioned.

Testing the 12v is getting from the Ign switch to the EFI relay base is the first thing I would check.

Believe the EFI relay contacts also supply power to lots of other functions, not just the the C\OPN relays contacts.

 

 

 

 

[Marc_lrfc]

Thanks for that I'll have a little tinker when I get home and see if EFI terminals are actually producing 12v to the relay in the first place! 

Im by no means a machanic but I am a engineer so will try and solve it if I can 

[oldcodger]

Is the car dead or still just usable ?   in a way dead should be easier to fault find.

[Marc_lrfc]

Update!

as I said I'm no machanic so please excuse me but I've just spent a bit of time out there with a meter and the EFI relay I thought I tested was in fact the fan relay!

come across the EFI relay and bang faulty! Swapped it watch horn relay and BOOM car has started! 

Thanks for all the advice guys and I'm just so chuffed it's not cost me a nice garage price with something so simple!

now for a new relay! Do you guys recommended anywhere I can get them at a tidy price? 

[oldcodger]

Nice one !

Your local Toyota dealer will get you one in a day or two or you might pick up a generic one from Halfords, Maplins, EuroCarParts etc.

Just search them under  'relay' and see if any match.

[Tacopilot]

 

I am looking into a similar situation. My fuel pump is not getting power. I started to troubleshoot and was about to post but I realize I made a mistake and need to recheck my work. I will post when I have some valid info.