P38 2.5 Inj Pump modulation issue.

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Wammers - just jumping in here for yours and other's sage advice as I've just checked my FIP.
I've checked my FIP after an hours drive so nice and hot. The mg/str is 5.5 at tickover, which is correctly at 750 with 128 fuelling on Nano. The modulation is at 75%, is that adjusted by the static timing or a different way?

If anyone wants to replace their FIP security bolt as I had to buy a bag of 10 and I have 7 spare, 1 for my spare FIP and one for Mark Piercy ;).
thanks :D
 
Mukiwa said:
Wammers - just jumping in here for yours and other's sage advice as I've just checked my FIP.
I've checked my FIP after an hours drive so nice and hot. The mg/str is 5.5 at tickover, which is correctly at 750 with 128 fuelling on Nano. The modulation is at 75%, is that adjusted by the static timing or a different way?

If anyone wants to replace their FIP security bolt as I had to buy a bag of 10 and I have 7 spare, 1 for my spare FIP and one for Mark Piercy ;).
thanks :D
Click to expand...
Static timing.
 
Mukiwa said:
Wammers - just jumping in here for yours and other's sage advice as I've just checked my FIP.
I've checked my FIP after an hours drive so nice and hot. The mg/str is 5.5 at tickover, which is correctly at 750 with 128 fuelling on Nano. The modulation is at 75%, is that adjusted by the static timing or a different way?

If anyone wants to replace their FIP security bolt as I had to buy a bag of 10 and I have 7 spare, 1 for my spare FIP and one for Mark Piercy ;).
thanks :D
Click to expand...

Wouldn't worry too much until it goes above 85%!
 
Mukiwa said:
Wammers - just jumping in here for yours and other's sage advice as I've just checked my FIP.
I've checked my FIP after an hours drive so nice and hot. The mg/str is 5.5 at tickover, which is correctly at 750 with 128 fuelling on Nano. The modulation is at 75%, is that adjusted by the static timing or a different way?

If anyone wants to replace their FIP security bolt as I had to buy a bag of 10 and I have 7 spare, 1 for my spare FIP and one for Mark Piercy ;).
thanks :D
Click to expand...

Static timing is the base setting for the pump at TDC. Slightly advanced, which the pump always returns to by way of spring pressure on the timing device piston when the engine is stopped. Dynamic timing is controlled by the ECU by way of the timing device within the pump, subject to signals the ECU receives from the CPS and number four injector. It will then vary the modulation to increase or decrease internal pump pressure acting on the timing device piston against spring pressure to get the point of injection as near as possible to TDC. . At 75% modulation your static timing will be slightly retarded. Less than 0.9 mm lift on cam at TDC engine off, mg/str can vary slightly even at steady idle depending on engine load at the time. If for instance you are sat at idle and engage gear the mg/str will increase to maintain 750 rpm against the load, select neutral and it will decrease. Same with loads applied by alternator, aircon etc. With new chains static timing is set at 0.95 mm lift at TDC. Over time as the chains run in and loosen up slightly it should drop to 0.9 mm static. This should give a modulation at idle engine warm of 50% plus or minus 5%.
 
wammers said:
Static timing is the base setting for the pump at TDC. Slightly advanced, which the pump always returns to by way of spring pressure on the timing device piston when the engine is stopped. Dynamic timing is controlled by the ECU by way of the timing device within the pump, subject to signals the ECU receives from the CPS and number four injector. It will then vary the modulation to increase or decrease internal pump pressure acting on the timing device piston against spring pressure to get the point of injection as near as possible to TDC. . At 75% modulation your static timing will be slightly retarded. Less than 0.9 mm lift on cam at TDC engine off, mg/str can vary slightly even at steady idle depending on engine load at the time. If for instance you are sat at idle and engage gear the mg/str will increase to maintain 750 rpm against the load, select neutral and it will decrease. Same with loads applied by alternator, aircon etc. With new chains static timing is set at 0.95 mm lift at TDC. Over time as the chains run in and loosen up slightly it should drop to 0.9 mm static. This should give a modulation at idle engine warm of 50% plus or minus 5%.
Click to expand...

Thanks Wammers, that clears up my knowledge gap. You are correct in that my mg/str is 5.5 +/- 0.5 at 750. On nano I can watch it vary from 728 - 750 but that's it.
Fuel injection boffin :D
 
Mukiwa said:
Ok, I'll change the fueling to 129 and see how it goes. The needle shows about 1mm above 750 when nano is showing 728-750
Click to expand...
Reading this lot, mine sits above 750 rpm, ive read the mg/str at 8 with my none nano and it goes like a demon.(not complaining)..
I dug the history from the last owner and it had a stage 2 tune up with a bigger intercooler. What bhp is the stage one?
This cost the owner £1200 in 2005!! I also discovered that dropping it into 3rd allows it to go into lockup in 3rd after a certain speed and goes very nicely when you drop the pedal.
Not abused as i quite like the drivetrain working in its current state. Anyhoo, mines up next for chains and tensioners when any bugger is ready??!!!;)
I really do love my bus, its absolutely ace.



Got my soppy coat..... :oops:
 
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