4age starting

[timgte]

hey
my 4age always takes a while to kick over. its as if the fuel pump isnt going when you first turn the key. If you turn the key and let it crank for a bit then stop for a second then crank again it fires almost instantly.
I have since rebuilt another 4age and put it in but it still continues to do it. So its not the motor.
Anyone experienced this? fuel pump?
Thanks

[kingmick]

starter motor turning over ok? might have a dud coldstart injector or you might not have preprime not working and the fuels running back from the rail. so it takes the first crank over to get it up there.

[timgte]

thanks kingmick
yeh the starter seems to be turning over ok.
unless the cold start injector on my new engine is also faulty, i'll check that out.
You mention "Pre-prime"?
How does that function and where do i start looking to repair it.
Cheers

[CHB]

this happened on my 3TC EFI too.. but i found on that if i let the fuel pump runs for another extra 4-5secs before cranking, it will fire up instantly..
how does preprime works?

[kingmick]

when you turn on the ignition, the factory computer preprimes the fuel system, it you turn on the ignition you sound her the pump start for a few seconds and then stop. in a rolla and the like its easy to here. if you dont hear it open your drivers window and bonnet and reach inside and turn it to ignition and you should up at the fuel rail as it primes. from memory it works of the relay under the the radio console in the ae series rollas that cuts the fuel pump if the engine is not going{ i.e as in a crash etc}

[RobertoX]

Yep, this relay is the 'fuel opening relay' on 4age wiring diagrams. Maybe check that it is operating properly.

Also either your fuel pump or your fuel pressure reg could be leaking pressure back to the tank when the ignition is off. And check that all high pressure fuel lines are in good condition and are not slowly leaking.

[timgte]

i'll check out those things on the weekend.
Thanks for the tips.

[andy jay]

it might also be time for a new battery, just a thought

[timgte]

ok cold start injector functions correctly, and the battery is fine.
When i get in the car in the morning, turn the key, there is no fuel pump. If i crank for half a second without letting it start, then i hear the pump for about 3 seconds and then the relay shuts it off. Shouldn't it be doing that when i first turn on the ignition before i start it?

[toyoda]

The fuel pump has a none return valve built into it.

This means that overnight - the fuel in the pipes stays slightly pressurised and all the way to the injectors for cold start.

If this non return valve leaks - then on the first start of the morning the pump has to prime the whole system before it builds up pressure.


Suggest you try there first.


Toyoda