zilspeed
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| posted on 21/8/05 at 02:05 PM |
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FAO BritishTrident
Andy (or anyone else for that matter)
Possible causes of Jerky throttle on a K series ? By jerky I mean no tickover and it only really runs correctly above 30% throttle. It pulls like a
train on anything above 50% throttle.
Throttle switch at the pedal perhaps ?
Oh, and it is no longer overheating and doesn't chuck it's water out 
[Edited on 21/8/05 by zilspeed]
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britishtrident
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| posted on 21/8/05 at 03:31 PM |
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It could be the throttle pot-- when thery fail they tend to fail at the low end rather than full throttle. Only real way to test it is connect it to
an oscilloscope and see it gives a smooth increase in signal over the full range -- I have a an PicoScope Oscilloscope printer port dongle for a pc
you could borrow to check it.
The Rover throttle pot is the same as the Granada 2.8i and I think the XR3i -- I have an Xr3i one in my garage.
However I had a similar problem on my 214Sli 2 years back it was the connector to the crank sensor -- these can be very iffy as can the crank
sensor itself which tend to fail giving poor starting and idling.
I would check the connections to the crank and throttle sensors also the multiplug connector to the mems unit and the earth wire to the mems unit.
Might be worth checking the conections at the back of the alternator aren't arcing as this causes the ECU to go crazy at certain RPM bands
and the vac connection between the throttlebody and the ECU hasn't got full of gunge.
The other Rover common fault that causes similar symptoms is the rotor arm -- these were modified in the early 90s modified units have a dab of red
paint on the shank.
[Edited on 21/8/05 by britishtrident]
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zilspeed
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| posted on 21/8/05 at 03:41 PM |
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Bingo - last tip, or at least very closely related to it. And the second last tip as well.
When I had put the rotor arm and distributor cap on, I had neglected to put the plastic shroud under the rotor arm. This affects the height of the
disributor cap in relation to the rotor arm. It seems that it might have been firng very poorly because of this. Put it back in and it immediately
fired up to a lovely smooth tickover. I also resecured the little black module that sends manifold depression to the ECU. This was also hanging
loose.
And it's still not overheating
[Edited on 21/8/05 by zilspeed]
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liam.mccaffrey
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| posted on 21/8/05 at 06:40 PM |
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britsh trident is magic, solved my k series problem(map sensorn pipe disconected)
I nearly got one of those picoscope kits, any good?
Build Blog
Build Photo Album
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NS Dev
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| posted on 22/8/05 at 11:56 AM |
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how much is the picoscope kit?
We have a few at work and they are superb. We even installed a couple on machines on the shop floor as on line monitors.
Never found out how much they cost though.
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iank
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| posted on 22/8/05 at 12:21 PM |
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Cheap(ish) - they look fine for automotive work, but the cheap ones don't look to have the bandwidth for most digital work or video.
http://www.picotech.com/order.html#oscilloscope
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britishtrident
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| posted on 22/8/05 at 12:49 PM |
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The l the Picoscope software is really best around.
The bottom end dongles like are just simple AD convertors anybody with a basic knowledge of electronics could knock one out --- these are fine for
most ,automotive stuff like checking crank sensors, but cars are getting more complex electronics and for proffesional use I would go for a top end
dual channel one.
[Edited on 22/8/05 by britishtrident]
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