Originally posted by tolsen
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Hesitating at full throttle ?
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Originally posted by Thrumbleux View Post
Fuel pressure regulator?
Another possibility is one or more injectors remaining open.
If fuel pressure should be around 4 bar above manifold pressure, then a drop to 1 bar is barely enough to overcome manifold pressure when the turbo is boosting and reducing fuelling to such an extent would make the mixture so lean as to not ignite at all - flame out.
Well the fuel pressure is even dropping under 1 bar. I don't think injectors are the issue. Wiring harness contact is unlikely the issue else the problem would occur even when the engine is cold. If the injector stay stuck open (faulty injectors), they should not resume normal operation as soon as we release the throttle. Moreover even with close to 100% duty cycle fuel pressure should not drop so much.
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Originally posted by marcjero View Post
I already replaced the fpr. I installed a 4bar model.
Originally posted by marcjero View PostWell the fuel pressure is even dropping under 1 bar. I don't think injectors are the issue. Wiring harness contact is unlikely the issue else the problem would occur even when the engine is cold.
Originally posted by marcjero View PostIf the injector stay stuck open (faulty injectors), they should not resume normal operation as soon as we release the throttle.
Originally posted by marcjero View PostMoreover even with close to 100% duty cycle fuel pressure should not drop so much.
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Originally posted by Thrumbleux View Post
As per Buckster, 'signal' to the FPR?
Originally posted by Thrumbleux View Post
Softening of wire, expansion, etc. A cold engine will accept (needs) more fuel.
And reduce the torque reaction....
Originally posted by Thrumbleux View PostAt say, 6000 rpm, and 100% duty cycle, the pump would have to be delivering circa 2.5 as much fuel as normal. Which would equate to 2.5 x 80hp = 200hp. The pumps are reckoned to be good for 130hp.
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Originally posted by marcjero View Post
Well I guess that the injectors at 6000 rpm and full boost should be at about 60-80% duty cycle. I don't see the 2.5 factor here. I think the flow can be 40% higher in the very worst case. I don't see the standard injectors able to produce 200hp even at 100% duty cycle.
Admittedly, the 8ms was a random figure I assumed typical of injector duration. Maybe for sequential systems it is.
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Originally posted by EmilysDad View Post
According to the book you have to, but in practice you can remove it without doing so .... just! I replaced the large O ring from under the pump & managed to do so without moving the tank.
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Originally posted by tolsen View PostCheapest complete fuel sender unit is £116.90 on misterauto.
http://www.autoperformanceengineerin...l/fpspecs.html shows some interesting data about the most famous Walbro pump. If you consider the smallest 190 lph model (gss242) you see that the flow drops a lot at after 80 psi. So the standard flow rate of a fuel pump doesn't matter a lot. What is the important is the flow rate at full boost. I see that gs242 could still flow a large amount of fuel at 80psi. Would be interesting to compare with gss284 figures. I guess that gss284 is flowing 110 lph at low pressure and 65 lph at 4.9 bar. gss242 could feed about 100lph at 4.9 bar. This is the reason I consider this model. It could support 120 bhp with E85 without any problem.Last edited by marcjero; 28-10-17, 12:13 PM.
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