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ourkid

Could someone please help me sort this out - It started with a bad relay,which i swapped for a used "spare" found in the car,i think this has gone again so i have a fused link/swith for now,which is actually helping in troubleshooting the pump.
Because it got VERY noisy and the car decided one morning not to start,i swapped it for a Sytec pump (not sure if you have these outside of the UK but it is the recommended alternative to the OEM supplied Bosch pump)

At the same time as fitting the new pump i stripped out the in-tank pump,which was dead,so i just have the pipe from the tank fitting to an in-line filter then to the external pump.

When i flick my bypass switch the pump operates and i can feel pressure in the discharge line,but after a few seconds the pump sounds like it's bogged down - i can't hear fuel returning back to the tank like i could with the old pump,and the car won't start.

This new pump should be capable of up to 9 bar,i'm not sure what to do next?

Ade.
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1983 924 N/A

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada

What flow is the after-market filter you added capable of?
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1987 951 - M193 Version for Japan

ourkid · Posted: Fri Sep 19, 2008 3:34 am Post subject:

Good point,I'm not sure but it's a large steel cannister type.Incidentally,is the cannister next to top strut mount in the engine bay another filter?

I've just cracked the union off the top of this and run the pump - i got a huge squirt across the garage!,so i'm getting pressure up there

I need to go back and re-understand the workings of the F.I system,is there a minium pressure requirement for the engine to run?,if so where is the best place to measure it?
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1983 924 N/A

ourkid · Posted: Fri Sep 19, 2008 4:43 am Post subject:

Just to update,

Ignition on,pump working,pressure up to distributor,

If i lift up the metering arm (from inside the airbox),then crack off a union from one of the top fuel line banjos,i hear a hissing noise but just a bubbly dribble of fuel - is this normal?
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1983 924 N/A

Rich H · Posted: Fri Sep 19, 2008 5:10 am Post subject:

Pull all the injectors, put each one in a milk bottle or similar so you can watch the spry pattern, short out the fuel pump relay so the pump runs then lift the metering plate, all the injectors should squite together.
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1994 Lotus Esprit S4 - Work in progress...
1980 Porsche 924 S2 DITC Turbo - Original spec
1978 Homo-Sapiens - Tired spec
1953 Landrover S1 - Pensioner Spec

ourkid · Posted: Fri Sep 19, 2008 5:47 am Post subject:

Thanks Rich,
just thinking ahead slightly,i have some time tomorrow to try and sort this out so gathering info now,If i find that i'm not getting a good squirt,what is the next step with troubleshooting? (i'm thinking fuel pump flow test)

Just to clarify what lead to this.The car wouldn't start so i assumed the fuel pump was the problem (been noisy for ages and getting worse),so the problem was there BEFORE I fitted the new pump,not necessarily caused by it.
Is there something inside the metering head/diss body that could cause loss of pressure?What if the CSV was leaking?

Ade.
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1983 924 N/A

Chickenwing · Joined: 12 Jun 2008 Posts: 45 Location: 07866

are your accumulators leaking?
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1977 924 4-speed

Chrenan · Joined: 15 Jan 2003 Posts: 3903 Location: Canada