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Engine starts but then is starved of fuel. Any ideas folks?


SilverMachine

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Hi all,

After bringing the 'old girl' back to life after sitting on her fat @rse for 5 years without moving (new brake lines and fuel line was all that was required for the mot) she has gone and let me down. I went to pull off from the drive and the engine cut out :blink:. I started her up again, but as soon as I start to feed the throttle, she dies. I checked to see if fuel was being pumped from the tank to rule out the fuel pump. All ok so far. I then went under the hood to see what was happening at the injectors. Again, fuel was bubbling through, but a bit dirty, so I removed the fuel filter (long overdue as it's the original one from 22 years ago and good for only 20yrs or 1million km) and replaced with a new one - £12.

 

Still not holding after starting her up. It's as if she is starved of fuel.

The car is stock standard original (except for a K&N air filter).

I'm not a mechanic so any help would be grateful.

 

Many thanks in advance.

Gaz

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Well I'm no mechanic but it sounds to me if it fires up and runs breifly the ignition side is ok.

 

Things you could do, take out the spare wheel, listen for the fuel pump noise and see if it dies when the engine dies? You can bridge two ports on the diagnostics to test the fuel pump, I'm not sure if it's advisable to do this and start the car though? Just thinking of trying to rule things out with my limited knowledge.

 

Does it turnover as fast as normal, or is it noticeably slower?

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Well I'm no mechanic but it sounds to me if it fires up and runs breifly the ignition side is ok.

 

Things you could do, take out the spare wheel, listen for the fuel pump noise and see if it dies when the engine dies? You can bridge two ports on the diagnostics to test the fuel pump, I'm not sure if it's advisable to do this and start the car though? Just thinking of trying to rule things out with my limited knowledge.

 

Does it turnover as fast as normal, or is it noticeably slower?

 

I've taken the spare out, undone the nuts and listened for the fuel pump on ignition. All hums as usual and pumps fuel into the back, so the fuel pump seems to work in sending fuel from the tank. I might get a bucket of fuel and bypass my fuel filter to see if it will start after checking the distributor cap.

 

It seems to turn over and run normally.

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  • 1 month later...

***Update***

 

Having had a friend lean into the boot when starting the old girl, the fuel pump seemed to work. To make sure that there was enough pressure coming through and pushing fuel through, I managed to borrow a pressure testing equipment. It turned out that the old fuel pump only pushed through 1.5bar of pressure. I then bought a new 'Kemso 340LPH' Fuel Pump and fitted this. Now getting nearly 3bar of pressure...but still not holding on idle after turning over. Still running for approx 10 sec before cutting out. New fuel filter fitted too.

 

Also checked dizzy and rota arm. Cleaned the coke build up on each contact on the cap and the arm in good condition. Creating a spark so all good there.

 

Still scratching my head with this. It is probably something really simple as the car has been running for 8 months without any problems, starting on every turn of the key and running like it should.

 

Any suggestions welcome or if anyone is in the North Wales area, please give me a shout. I would welcome the help.

 

Thanks in advance.

Gaz

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I had this on my 1jz soarer. the car would start every time and run fine for about 10 secs and then it would die. turned out the fuel pump ecu has a high and low voltage output (9v and 12v from memory) but I was only getting 1 of them so it would die when it switched over.

is the pump definitely running all the way to when the car stops?

there was a diagnostic port under the bonnet where I linked a wire between "+" and "fp" to give a constant 12v feed to the pump when the ignition is on.

I cant remember if the supra has it but it might be something similar?

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  • 3 weeks later...
I had this on my 1jz soarer. the car would start every time and run fine for about 10 secs and then it would die. turned out the fuel pump ecu has a high and low voltage output (9v and 12v from memory) but I was only getting 1 of them so it would die when it switched over.

is the pump definitely running all the way to when the car stops?

there was a diagnostic port under the bonnet where I linked a wire between "+" and "fp" to give a constant 12v feed to the pump when the ignition is on.

I cant remember if the supra has it but it might be something similar?

 

Thanks Squiffy,

sorry for the delay in getting back to you. I've been away with work and then away on holiday with no internet access.

 

I managed to spend some time on the 'old girl' over the least few days. I disconnected the alarm thinking it might be something cutting off the fuel, then my friend came over and tested the Fuel ECU. The dry connectors seemed burnt on the PCB when he took it apart, so he put the probe of the volt meter into the connector for the dodgy wire...and viola! The car idles. So, we looked on here for the get around on the 9v / 12v feed. Job done.

 

Thanks everyone for your suggestions and help. The car is back alive!

Gaz

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