Datatek
Well-Known Member
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- 44,008
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- Near Poitiers SW France
Modulation on mine when hot at idle is 57 from memory, Wammers is your man for this.
vibrating
- Thread starter timh1970
- Start date
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- Posts
- 58,170
- Location
- Preston Lancs.
Timing modulation with the engine at normal temp should be between 45% and 55% ideally 50%. Actual injection percentage should be around 0% to 1% or so from TDC. That would indicate that the static pump timing was correct. The ECU receives a signal from number four injector at start of injection. This is compared to signals from two position pins spaced 40 degrees before and 20 degrees after TDC which are read by the CPS. The timing solenoid is then modulated by the ECU to correct any deviation caused by static timing error from the mapped need for that particular engine speed. If the modulation is down at 4 or 5 that means the timing solenoid is down near it's limit as far as retarding the point of injection. That would indicate that the static timing is far to advanced.
Why would it be at 11.9 when idle and then drop when you give it a little gas? Timing chain / tensioner worn perhaps?
Thanks for your help BTW.
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- Posts
- 58,170
- Location
- Preston Lancs.
If everything is otherwise functioning correctly. If the timing chain is stretched the static timing will be retarded and give an high modulation. If the static is advanced it will give a low modulation. Null point for modulation is 50%, that gives movement in either direction to correct point of injection.
I had it up at Colne the other day and he said it was a recon pump on it so perhaps whoever put the pump on did not know what they were doing.
I've only had the car for around 4 months and I bought it as a shed with more things wrong with it than right. I am down to 2 faults on it now (3 if I include the fact that i need a key with an EKA code); the vibrating and the Air Con.
The vibrating seems to be particularly bad when the modulation is down at 4.67 but it is not easy to tell because even if it was there after 2K revs it would be difficult to detect.
Why didn't they make the inlet manifold clip on
It's been off 3 times now in the last fortnight (Once for a leaking injector, once for replacement glow plugs and once so that I could get to that plug on injector N0.4 to see if pulling it made a difference to the vibration.
I've only had the car for around 4 months and I bought it as a shed with more things wrong with it than right. I am down to 2 faults on it now (3 if I include the fact that i need a key with an EKA code); the vibrating and the Air Con.
The vibrating seems to be particularly bad when the modulation is down at 4.67 but it is not easy to tell because even if it was there after 2K revs it would be difficult to detect.
Why didn't they make the inlet manifold clip on
It's been off 3 times now in the last fortnight (Once for a leaking injector, once for replacement glow plugs and once so that I could get to that plug on injector N0.4 to see if pulling it made a difference to the vibration.
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