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1995-2002 Range Rover P38A
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Discussion Starter · #1 ·
Hi guys!
I am writing to you from Russia. And I have the following problem!
Ordered a two cam- Paiper Cam 280. Set them on two cars. З38 4.6 GEMS and Disco2 4.0 Bosch.
After installing the rolls. Both engines idling unstable and high fuel consumption.
Please tell me what I did wrong and how to fix this problem? The first time I installed Paiper Cam 280 And don `t know all the details.
 

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Premium Member
1995-2002 Range Rover P38A
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626 Posts
You don't need to reset the adaptive values as the computer will eventually do it itself.
You do however need to break in the Cam Shaft and the best way to do this is as soon as you start the engine after rebuild take the revs to 1750 -2000 rpm and keep them there for 20 minutes. Also your engine will run a little rough regardless of what you do for the first 1000 or so miles until everything settles in. Try not to let the engine idle excessively during this break in period to avoid spinning any bearings.
 

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A 280 deg camshaft has a lot more overlap than the standard cam and so you can expect rougher idle characteristics than for the standard cam profile. It should however, smooth out as the revs rise. Also, if you use standard springs, the maximum lift is restricted to 10.9mm. Your Piper 280 may have more lift than this and so may require longer valve springs. It's not surprising that you use a lot more fuel with a longer duration camshaft as it is meant for higher rev performance.
 

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I don't think it's possible to change such a component and expect the standard fuel/ignition maps to cope, Mark Adams chip and rolling road sessions you could perhaps do something.
 

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JACK'S GRANDAD
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9,270 Posts
Not familiar with those camshafts myself, so here are a few run of the mill suggestions.
Reset the adaptvie values as a start, see if that fast forwards the learning curve.
Too late for me to look up the specs on the cams, but thinking if what Hoges says is right (and it normally is), then you need to address the heads too. Did you install new lifters too (I hope so)?
Break in the cams correctly?
Measure the pushrod tolerances?
Measure the spring rates to see where they are at?
There is a LOT more to just dropping in a new camshaft when you reach a certain level. Past that certain level, and you need different pushrods, valve springs, and so on.
My old rally car HAD to idle at over 1000rpm's due to it's camshaft years ago, and took a lot of dyno time to tune the triple Weber's correctly too.
As Larry said, you may need to alter the fueling maps to account for the longer duration and higher lift. More lift and duration needs more fuel. A High lift cam will have a lumpy idle too, no way around that really.
Measure the vacuum on the intake manifold too, and post the results

Martin
 

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1995-2002 Range Rover P38A
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Discussion Starter · #7 ·
Thank you very much for your answers!
Of course I installed new lifters as well as new gear and chain.


The valve springs I nashol them on sale! Even the camshaft I brought a friend from London. In Russia we do not buy it!


I am very grateful for the booth for more information about springs and a chip.


And as for the information in London where you can buy them.
 
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