Moorron
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| posted on 2/1/07 at 08:10 PM |
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rover v8 problems. anyone experts here?
Long shot i know, its my land rover classic with a new JE stroked 3.9 v8 (4.6).
i drive it at low revs most of the time, but over the last couple of months its 'hunted' at lower revs almost a misfire. i have changed
the plugs but still it does it.
Its also started to try and stall at junctions, but not evertime, it drops to 100 rpm (or so low u cant hear the engine) then either stalls or jumps
back to 1100 rpm. Ive checked the timing and all as was before these problems accured.
What could it b?
MPG has dropped alittle but not anought to point to fueling (its injection).
Any help?
Sorry about my spelling, im an engineer and only work in numbers.
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rusty nuts
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| posted on 2/1/07 at 08:39 PM |
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Try cleaning the Idle Speed Control Valve with carb cleaner , that may help
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Moorron
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| posted on 2/1/07 at 08:43 PM |
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does this just unbolt without springs/bits flying every where or is it a case of cleaning it in situ up the inlet manifold cover?
[Edited on 2/1/07 by Moorron]
Sorry about my spelling, im an engineer and only work in numbers.
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froggy
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| posted on 2/1/07 at 09:08 PM |
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i take it its the hotwire system then, which year is the engine then?
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marcjagman
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| posted on 2/1/07 at 09:12 PM |
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These engines love rotor arms and dizzy caps and they don't cost a lot eith, about £20/pair.
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mark chandler
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| posted on 2/1/07 at 09:46 PM |
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Does sound like the idle valve thing, these do not fall apart/spring into a hundred pieces, it works with a taper being pushed and pulled into a hole,
just pluck from the front top of the plenum, soak the dirty end in petrol, carb cleaner etc shake a bit and drain out the gunk.
Spray the now clean end in wd40 and restore.
Regards Mark
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ed_crouch
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| posted on 2/1/07 at 10:03 PM |
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Identical problem I had with my TVR. If you have a mid 80's engine, using a flapper air flow meter and Lucas 4CU EFI then its not fitted with an
idle control valve.
The engine has no active idle control with the exception of the bimetallic extra air valve fitted along the front of the plenum chamber in front of no
2 injector (raises the engine idle when its cold, but does nothing to stabilise RPM).
It may, however, be fitted with a Lucas 35DLM8 (or another very similar, with ignition amp under the coil: they're fecking expensive to replace,
have a look at Rimmer Bros!) distributor, which uses a VR sensor to generate a spark pulse instead of points. You can identify this distributor by
the fact that it has a small matchbox shaped unit on the side, attached by 2 screws, and 2 spade connectors on the top. This is the ignition
amplifier, and yours is starting to die.
Replace it. I could be wrong, but i doubtt it from the symptoms you have described.
My car went well, and all the rest of it, but was a bag of poo in traffic, and as soon as it warmed up, the idle went to rats, and no end of idle
mixture adjustment would cure it.
35 quid for a new one, and al was fixed instantly.
If you want to check it, put your inductive pickup strobe gun around the KING lead, not the no.1 HT, and shine it at the bonnet or something. You
should see a faint and spluttery series of flashes: i.e an uneven rhythm.
When you're replaced the amp, you will see a much brighter and steady stream of flashes.
Im 99% sure youve got a misfire caused by the semiconductors in the ignition amplifier dying. If you leave it long enough, the misfiring will start to
blight the whole rev range and then the car wil break down.
Hope this helps: its quite fresh in my mind. Pls U2U me if you want more info!
Ed.
P.S. I guess this approach is risky if youre epileptic!
[Edited on 2/1/07 by ed_crouch]
I-iii-iii-iii-ts ME!
Hurrah.
www.wings-and-wheels.net
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Moorron
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| posted on 2/1/07 at 10:12 PM |
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nice set of replies cheers guys.
I think the first thing to do is take the idle valve out and clean it, then if it doesnt work i will get a new dizzy and rotor arm.
If its not this then i will look at the amp.
Im not sure what engine it is as my friend did it all when he owned it before me. All i know is its a brand new 4.6, balanced bottom end, modded heads
and for some strange reason runs lots of advance (about 14 degrees). It doesnt pink at this, but did make the old s/steel manifolds glow red AT
IDLE!!!!
i will post back with my results.
thanks
edit! its not got the amp under the coil so i dont think its like your TVR. It is hotwire with the idle valve.
[Edited on 2/1/07 by Moorron]
Sorry about my spelling, im an engineer and only work in numbers.
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ed_crouch
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| posted on 2/1/07 at 10:22 PM |
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K. its Lucas 14CU then, which is the hotwire system. You might be best asking on the TVR Chimeara/Griff sections of www.pistonheads.com/gassing.
May still be worth doing the strobe gun test tho (if youve got one!), as this will either indict or acquit the ignition system!
Ta.
Ed.
Edit: if the 14CU system has an ignition amp (IIRC it does), its probably on the side of the dizzy.
You could just ditch the bloody distributor as they arent very god, and put a Mallory unilite on it (£375 though: Owwwwwwowwowowowow).
[Edited on 2/1/07 by ed_crouch]
I-iii-iii-iii-ts ME!
Hurrah.
www.wings-and-wheels.net
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Agriv8
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| posted on 2/1/07 at 10:58 PM |
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1st thing to check Air leaks can cause all sorts of funnies with the hotwire unit.
2nd unplug ecu for 15 seconds and try again.
dou you run lambda sensor?
let me know if you need them but i have a 20 page LR fault diag test pdf file ( all you need is a multimeter ) it will fault find most stuff can
email if i can remeber where I have saved it !!.
regards
agriv8
PS running Hotwire
Taller than your average Guy !
Management is like a tree of monkeys. - Those at the top look down and see a tree full of smiling faces. BUT Those at the bottom look up and see a
tree full of a*seholes .............
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Moorron
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| posted on 4/1/07 at 10:03 PM |
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update!
removed the air bypass valve and it was dirty, cleaned it out and my idle/stall problem is solved. THANKS
But it still hunts/slight misfire when cruising at low RPM. so i am going to replace the dizzy and rotor arm to see if this helps.
My coil is alone so the amp must b under the seats in the cab. Hopefully i wont have to get to it as its a pain to remove the seats.
Sorry about my spelling, im an engineer and only work in numbers.
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