tomcat59alan
Well-Known Member
That thought went through my mind.
Lachleaves1
Member
When you say ' playing with the top of the FIP' - in what way? And in any case, it's only me that's had for the past 6 months.
If you take the top of the FIP off it can get a bit funny unless you put it back in EXACTLY the same spot. Often the seals on the pump go so you have to take it apart to replace them.
tomcat59alan
Well-Known Member
Is the top of the FIP loose? The top section can be removed but the one below it will effect the tickover if it is loose or ,if removed, is not replaced in the exactly the original position.
Correctamundo.
That does not effect idle.
Lachleaves1
Member
Thanks so much for the offer - welcome to drop by anyway, but. ...
Guess what..? Range rover hunting/idle problem cured: both injector pump mounting bolts were loose!!! Yippee
Guess what..? Range rover hunting/idle problem cured: both injector pump mounting bolts were loose!!! Yippee
Thanks so much for the offer - welcome to drop by anyway, but. ...
Guess what..? Range rover hunting/idle problem cured: both injector pump mounting bolts were loose!!! Yippee
Sounds like the last bloke to work on the pump was a bit of a clog head.
tomcat59alan
Well-Known Member
Why is your car standing on it's nose and you lying on your back?Thanks so much for the offer - welcome to drop by anyway, but. ...
Guess what..? Range rover hunting/idle problem cured: both injector pump mounting bolts were loose!!! Yippee
Thanks so much for the offer - welcome to drop by anyway, but. ...
Guess what..? Range rover hunting/idle problem cured: both injector pump mounting bolts were loose!!! Yippee
Result. IIRC the position of the pump is reasonably critical so presumably you had the timing tools? Or did you have diag and just set it to 50% modulation?
welshsteve
Member
Guessing neither, if the bolts were loose the timing of the fuel pump needs to be checked to at least confirm it is correct.
Lachleaves1
Member
Oh dear. I'm sure you're all horrified to hear that all I did was tighten the 2 nuts. Seems to run fine!
Not good?
Not good?
Lachleaves1
Member
...I thought I'd take it at an angle like one off those old Batman action shots!Why is your car standing on it's nose and you lying on your back?
A modulation check would be easiest way.
I think it is more robust than we are led to believe but ideally the pump has to be in a certain position otherwise the electronic bit in the top of the FIP that does the fine-tuning might find itself unable to adjust itself in a direction and cause a fault.
If it was much to advanced or retarded you would get modulation out of range fault. If it was to far advanced you would get low modulation if to far retarded high modulation.
Lachleaves1
Member
...resulting in? ?
To far retarded bad hot starts. Static timing is set with .90 mm lift on cam. This gives slight advance for starting, the timing device in the pump is spring loaded so always returns to this setting when engine is cold or has been stopped for a time when hot and internal pressure has bled away. When engine is hot no cold start fuel is set by ECU so a retarded static can give hot starting problems. As the engine speed rises internal pump pressure increases until a pressure relief valve opens and returns fuel to the inlet side of the internal high pressure pump. The ECU receives a point of injection signal from the number four injector and uses this in conjunction with readings from the crank position sensor to modulate the timing solenoid, to control fuel pressure exerted on the timing device so that the point of injection remains at TDC no matter what the pump internal pressure is. Modulation at idle, warm engine, should be around 45% to 55% ideally 50%, the modulation solenoid can then go either way to control pressure on timing device subject to engine RPMs and internal fuel pressure. If the static timing is to far out either way it may not be able do this within it's range of operation, so the ECU will throw a modulation out of range fault.
