Matt Quinn
Member
As the title suggests I'm looking for some specific numbers (and some cogent discussion as to how they might be interpreted) with respect to the 1.3 JTD Diesel engine particularly (though not exclusively) as fitted with the Bosch CP1H3 pump such as the 0 445 010 266 - My own particular interest is in a Euro 5 compliant vehicle; but I'm happy to hear of experiences across the range. My objective here is more to open a discussion that won't just help me; but others in the future.
If anyone can direct us all to published charts and reading material or the like that would be useful. Equally well if people have readings or notes (or just know what to expect) from actual vehicles great. I've not specified a particular vehicle here for the simple reason that if this data emerges coherently - well it might become a useful source for others trying to diagnose a fuel pressure related issue.
(1) Fuel Rail Pressure: Figures read over OBD (i.e. what your average gadgie will see on their normal home scanner tool) at various RPM would be very useful. i.e. idle, 2000 rpm, 3000 rpm. - What should you expect to see if you floor the throttle for a moment or hold the engine briefly at (say) 5000rpm? - Where is the ball park?
(2) Leak back test figures... NOT the 'wel you looks in the old pop bottle, so you does; an' if one is fuller than the other'
- Lots of that on YouTube! I'm half expecting to come across advice that includes sticking a leak-back tube in each ear and up each nostril, then seeing how long it takes for your head to explode!
I'm thinking here mainly about the possible situation where the leak-back from an injector is severe enough that the high pressure pump can no longer maintain adequate pressure to the rail... Data, data data; solid facts to go on.
Purely as an example to kick things off...
According to the Merlin Diesel Systems data for their S3000 test system 0 445 110 083 injector (which I think is) fitted to my particular vehicle - when pressurised at 1350BAR (1500rpm) with a 900μs pulse applied, may permissibly leak back up to 55ml per minute! - That being the 'max fuel' parameter.
At 400rpm/700ms/250BAR they say less than 9ml/min or 12.5ml/1000revs - which means that at an 800rpm idle, leak back should be less than 18ml/min. The 'seat test' where the injector is pressurised to 1350BAR but not fired, needs to be under 25ml/min. Of course all that's on a test bench; what happens on the car may well be a different matter.
A few sources seem to cite <25ml/min (i.e. the seat test value) as the maximum permissible leak back rate for the engine as fitted to a car. If you feel this is correct or incorrect - and can explain why - your input would be useful.
Better still if some manufacturer's figures can be cited and referenced.
If anyone can direct us all to published charts and reading material or the like that would be useful. Equally well if people have readings or notes (or just know what to expect) from actual vehicles great. I've not specified a particular vehicle here for the simple reason that if this data emerges coherently - well it might become a useful source for others trying to diagnose a fuel pressure related issue.
(1) Fuel Rail Pressure: Figures read over OBD (i.e. what your average gadgie will see on their normal home scanner tool) at various RPM would be very useful. i.e. idle, 2000 rpm, 3000 rpm. - What should you expect to see if you floor the throttle for a moment or hold the engine briefly at (say) 5000rpm? - Where is the ball park?
(2) Leak back test figures... NOT the 'wel you looks in the old pop bottle, so you does; an' if one is fuller than the other'
- Lots of that on YouTube! I'm half expecting to come across advice that includes sticking a leak-back tube in each ear and up each nostril, then seeing how long it takes for your head to explode!I'm thinking here mainly about the possible situation where the leak-back from an injector is severe enough that the high pressure pump can no longer maintain adequate pressure to the rail... Data, data data; solid facts to go on.
Purely as an example to kick things off...
According to the Merlin Diesel Systems data for their S3000 test system 0 445 110 083 injector (which I think is) fitted to my particular vehicle - when pressurised at 1350BAR (1500rpm) with a 900μs pulse applied, may permissibly leak back up to 55ml per minute! - That being the 'max fuel' parameter.
At 400rpm/700ms/250BAR they say less than 9ml/min or 12.5ml/1000revs - which means that at an 800rpm idle, leak back should be less than 18ml/min. The 'seat test' where the injector is pressurised to 1350BAR but not fired, needs to be under 25ml/min. Of course all that's on a test bench; what happens on the car may well be a different matter.
A few sources seem to cite <25ml/min (i.e. the seat test value) as the maximum permissible leak back rate for the engine as fitted to a car. If you feel this is correct or incorrect - and can explain why - your input would be useful.
Better still if some manufacturer's figures can be cited and referenced.
