I have a 205 gti 1.9 which is massively overfuelling! I have changed the pressure regulator, air flow meter, fuel pump relay even the ecu and it still pumps a ridiculous amount of fuel into the rail, therefore flooding the barrels. The car is a 1.6 body and gearbox with a 1.9 engine, since the engine was fitted it has never ran correctly. People keep talking about a tachymetric relay! Where is this relay on the vehicle, I have spoken to my local dealer who do not have a clue!!! Could this be causing the problem? Is it true that the fuel pumps are either on or off on these? Should it be supplying a constant run of fuel across the rail? The only thing i can think of is maybe the coolant temp sensor but the worry i have is the amount of fuel it is pumping, it quarter fills a 5 litre jerry can in about 20 seconds of cranking!
Somebody please help!!!
Changing the ecu sorted an injector problem i had but i still have overfuelling!
s
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I think you need to read up on fuel injection basics. There should always be a huge flow of fuel passing through the rail at a constant pressure - can't remember these exactly, but 35-40 psi is typical.
Fuel metering is done by pulsing the injectors milliseconds at a time. That is the ECU's basic function.
If this is a mix-and-match, then you've got a nightmare on your hands. Does it even run?
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it should be getting 540cc of fuel every 15 seconds according to peugeot, i dont know what pressure that is.
yes the car runs perfectly once you stem the flow of fuel, i.e clamp the hose supplying the rail.
the engine change was done proffesionally but we just cant work this out!
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You're looking completely in the wrong direction. All you need is the correct pressure in the rail, [3 bar - no vac] which is controlled by the pressure regulator valve. That can be measured with a suitable test gauge, but is rarely wrong unless something blocks the return pipe.
Doesn't matter if there's a hundred gallons an hour flowing round the loop and back to the tank; the pressure should be stable and that's all. As said; the injector duration is the metering mechanism - measure that.
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I can't really phrase it better than Screwloose, excpet to say that you are almost certainly looking at the wrong thing.
Check to see if the voltage at the injectors is pulsing - **If** the injectors are switched on all the time, you will get massive over-fuelling.
**If** they are pulsing, find out how long they are switched on for - at tick over, I'd expect a value around 2 milli seconds per pulse.
**If** the pulse is much longer, you need to find out why - you need to find which sensor (or wiring associated witha sensor) is "lying" to the ECU.
Number_Cruncher
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Sorted it! Coolant temp sensor! But now I have a different problem, it's smoking a bit which im pretty sure is oil related, i think valve stem seals, this is pretty common right??? But shouldnt it stop once the engine is warm???
s
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Could be stem seals... How good is this engine? Most 1.9 Gti's have had a hard life?
Done a compression test?
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yeah compression is fine, this car has been sat for 6 years doing nothing, its basically a freshly built engine tuned for hill climbing, its had thousands spent on it. I know it would have had alot of fuel etc in the system from where it was overfuelling, i have left it ticking over for a good few hours today and the smoke seems to have cleared a little! Could those stem seals have completely hardened and cracked over time?
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Why would you even fit stem seals on a race-prep engine? More lube is good - smoke doesn't matter.
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Almost certainly valve stem oil seals - a very common occurnace on the XU series engines.For all things 205 related get yourself over to www.205gtidrivers.com
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