Moorron
|
 posted on 24/9/07 at 08:18 AM |
|
|
Hotwire RV8 help B4 i smash it up!
Please for the love of god can someone help me?
I hate intermiten faults and i have a stonker of one on my Tin top RV8.
Its a long post as its been going on for some time.
Range rover 4.6 (stroked 3.9) with a upgraded cam, air filter and exhaust. All was running fine on this engine for 2 years.
Ploblems started about 6 months ago, just hesitant on part throttle in the lower part of the rev range. I serviced it but it didnt solve the
hesitancy. It would also be intermitent which did my nut in.
It got worse and also developed into the odd stall at junctions. I checked the timing and this seemed within book figueres. However, it got worse to
the point of my having to keep the throttle down a small amount to stop it stalling, again it was intermitent.
I replaced the dizzy cap and rotor arm (the cheapest parts) but it made no difference. I put up with it for a few months, but it then degraded again
with the new problem of not starting, it would spin fine, but smelt like it was overfueling. It would chugg to start and then missfire when i reved it
up, this seemed to 'clear it' but would still hunt.
I took off the air bypass valve/solinoid and cleaned it out and this did improve it but not solve the intermitent problems.
The starting problem got worse and has now being intermitent for about 4 months, so i took it to a range rover place where they fitted a new water
temp sensor and tuned the engine. This did nothing as a few days later it came back.
So off i popped to a spares place and bought all the cheapest parts i could think of with the intention to replace one at a time when it was playing
up, air bypas valve, coil, spark plugs and leads.
I thought it was sorted when i replaced the air bypass valve, but after leaving it over the weekend it wouldnt start this morning, just spun over
without even a stutter. it has a spark but wont fine up.
I HATE being in the position of not knowing what to do next, if i take it to a car place to get it fixed they are just going to have the same problems
i will have and the chances of it 'playing up' when it gets booked in is 50/50.
I have really had enought and i think my neighbours have too, 7 am and 30 minutes of me cranking it over abd now a flat battery.
Please suggest something.
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
|
|
JAG
|
| posted on 24/9/07 at 08:33 AM |
|
|
Have you checked the air flow meter is giving a good signal and varying the fuelling to suit the engines operating conditions?
I have had similar symptoms with my MX5 engine and found it was due to the air flow meter.
All of your symptoms sound like poor fuelling.
In my case it's a flap type meter but your hot wire AFM could be just as bust.
Justin
Who is this super hero? Sarge? ...No.
Rosemary, the telephone operator? ...No.
Penry, the mild-mannered janitor? ...Could be!
|
|
|
nick205
|
| posted on 24/9/07 at 08:38 AM |
|
|
Is it carb or injection?
If injection, does it have an air flow meter, one of the older flap type ones? The sysmptoms you describe sound similar to problems I had when the
air flow meter was failing on a Pug 205. The reisitive position element of the meter starts to disintegrate and gives the ECU a real hard time trying
to compensate for it.
Of course i it's carb based then that's no use to you at all 
Edit to say...
Beaten to it & Great minds 
[Edited on 24/9/07 by nick205]
|
|
|
darrens
|
| posted on 24/9/07 at 08:41 AM |
|
|
I had a very similar problem with my 3.9, although it would start fine, it would buck under accel, be hesitant and junctions, wouldn't
accelerate past 2500rpm. Drove me nuts for ages. As I was using MS I put it down to my lack of knowledge on tuning, but it eventually did my crust in
too much.
Faulty distributor was the cause of all the problems. I had originally eliminated this by changing rotor arm, dizzy, cap, new leads etc. Vacuum
advance working ok. It seems that there was enough play in it to cause timing scatter.
I changed over to wasted spark system (direct coil on plug vitually). Even when the dizzy was good, it was never as good as it is now, response is
instantaneous, tickover is miles smoother, even with the square CAM fitted. Not saying yours is the same, but It may be worth trying another dizzy to
eliminate it. I also (I think) have a spare airflow meter in the garage if you want to try that.
Cheers
|
|
|
02GF74
|
| posted on 24/9/07 at 09:01 AM |
|
|
you would be better off posting this on land rover forums.
my v8 is carbed so unfortuantely for you, I don;t pay much attention to fuel innjected engine woes. A lot of the time it is some component that needs
cleaning.replacing - stepper motor for the air control valve? ( sorry, can't remember the exact part).
|
|
|
Agriv8
|
| posted on 24/9/07 at 09:01 AM |
|
|
Ahhh the good old Hotwire system.
From your description I would say its the Dizzie that at fault - But that a gut feeling.
Have a look on here and let us know which one you have ( 1/2 way down the page ) it also has a lot of usfull info on the 'Shortcummings of
either unit'.
RV8 Dizzi info - RPI.
I would suspect you have the middle one ( with the control unit on the side of the dizzie ). IF you have ( You can buy the control unit seperatly for
£20 / 30 ) I have detals somewhere.
Check this first .
Regarding the Hotwire operations I have the full Range Rover Hotwire Test manual in PDF. This will enable you to test all the relevant parts of the
system with a decent Multimeter. U2U me your email address and I will forward it to you ( though may take some finding ).
PS I have just upgraded my Hotwire to VEMS so have a garage of Hotwire bits including ammases spares.
Kind regards
Agriv8
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 .............
|
|
|
Moorron
|
| posted on 24/9/07 at 09:23 AM |
|
|
thanks for the replys. Mine is the middle dizzy.
some things i forgot to mention, i replaced the advance unit as it was broke. but it didnt change the problems.
Aslo it has been 'chipped' by the last owner. i have the original chip but im unsure if its a diy job??
Having replaced alot of items im left with, ecu, afm, dizzy unit and fuel items.
I would love to borrow/buy a spare AFM and throttle position sensor if one is available from you guys. Please give us a U2U with the price and i will
sort it out.
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
wilkingj
|
| posted on 24/9/07 at 10:26 AM |
|
|
This is not the answer you want to hear.
However, If you are using Std Rover injection, what was it from? 3.5, 3.9, 4.2, 4.6???
Each ECU will be programmed for that sort of engine capacity / fueling, Cam, ignition etc etc ie the Maps.
If yours is a 3.9 stroked to 4.6, then you can guarantee that the mapping is not 100% correct, and you could expect some issues.
Why not throw away the Rover injection, and just fit a Megasquirt? OK it will cost to get it mapped properly. But you will then get the full benefit
of the other modifications to the engine. Its got to be a better solution to what you have.
As I said, its not the answer you want to hear.
Other than the above, cant help with the problem. I'm all carbed up.
but hoping to do a Megasquirt conversion to throttle bodies on my RV8
Oh and throw away the Dizzy and use the Ford Coils driven directly from the MSquirt.
[Edited on 24/9/2007 by wilkingj]
1. The point of a journey is not to arrive.
2. Never take life seriously. Nobody gets out alive anyway.
Best Regards
Geoff
http://www.v8viento.co.uk
|
|
|
Agriv8
|
| posted on 24/9/07 at 10:28 AM |
|
|
Hi Moorron,
U2U and email sent.
Ahh so you have swapped the Dizzie unit so possibly count that out ( unless that dodgy as well) I have spare control module somewhere.
Did you check to see if you had a spark when she wont start ?
let us know if you have a spark or not regards
Agriv8
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 .............
|
|
|
Agriv8
|
| posted on 24/9/07 at 10:34 AM |
|
|
quote:
Originally posted by wilkingj
This is not the answer you want to hear.
However, If you are using Std Rover injection, what was it from? 3.5, 3.9, 4.2, 4.6???
Each ECU will be programmed for that sort of engine capacity / fueling, Cam, ignition etc etc ie the Maps.
If yours is a 3.9 stroked to 4.6, then you can guarantee that the mapping is not 100% correct, and you could expect some issues.
Why not throw away the Rover injection, and just fit a Megasquirt? OK it will cost to get it mapped properly. But you will then get the full benefit
of the other modifications to the engine. Its got to be a better solution to what you have.
As I said, its not the answer you want to hear.
Other than the above, cant help with the problem. I'm all carbed up.
but hoping to do a Megasquirt conversion to throttle bodies on my RV8
Oh and throw away the Dizzy and use the Ford Coils driven directly from the MSquirt.
[Edited on 24/9/2007 by wilkingj]
Or Range-rover ones run from Vems I dont think I will ever go back to a dizzie again !!! to be honest I am running mine ( on self tune Mode ) and
its drives a lot better than the Hotwire.
regards
Agriv8
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 .............
|
|
|
Moorron
|
| posted on 24/9/07 at 10:56 AM |
|
|
im charging the battery as we speak, but its hoofing it down outside so it maybe later today or tommorrow when i get back on it.
Knowing my luck, when i put the battery back on it will start straight up!
Ive looked on the RPI link and seen how to check the throttle pot. Will do this too if its still playing silly buger.
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
Agriv8
|
| posted on 24/9/07 at 01:50 PM |
|
|
Moorron.
That 6mb PDF got through Yet ?
Regards
Agriv8
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 .............
|
|
|
timf
|
| posted on 24/9/07 at 02:43 PM |
|
|
does it have a k&n or any type of oiled filter
clamped onto the airflow meter as these can often cause problems as the oil can get drawn over the wire and causes problems
A prisoner of war is a man who tries to kill you and fails, and then asks you not to kill him."
- Sir Winston S. Churchill, 1952
|
|
|
Moorron
|
| posted on 25/9/07 at 10:51 AM |
|
|
Update.
After refitting the charged battery i tried a few other things,
Disconected the TPS, still no change.
Changed king lead. no change
Took off dizzy cap and sprayed WD40. Started first time but with a misfire, after a few minutes it cleared.
The culprit looks like the cap, arm or dizzy unit it self. Ive noticed looking on a few forums that they say non OEM part cap and arm cause troubles.
Im unsure when i replaced mine 6 months ago if it was a replica job or not. So of to but a real set.
I moved the arm by hand while the cap was off and noticed some rotational play, is this normal?
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
Agriv8
|
| posted on 25/9/07 at 01:38 PM |
|
|
MMMmmm must say I dont know on that one.
Regards
Agriv8
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 .............
|
|
|
TL
|
| posted on 25/9/07 at 09:36 PM |
|
|
Yes, some rotational play is normal.
The top of the distributor shaft (the bit where the rotor arm fits) is not directly connected to the lower part of the shaft; The lower part of the
shaft turns a plate with the bob-weights attached. The bob-weights spin out under centrifugal force when the revs increase (they return at low revs
because they are spring loaded). The bob-weights are linked to the top part of the shaft, so that when the bob-weights "expand", they move
the top shaft relative to the bottom shaft, and advance / retard the timing.
The profile of the bob-weights, and the strength of the return springs are what control the advance curve. Basically, they perform the engine speed
part of old skool ignition mapping.
HTH,
Cheers,
Terry
|
|
|
Moorron
|
| posted on 26/9/07 at 06:36 PM |
|
|
quote:
Originally posted by Agriv8
Moorron.
That 6mb PDF got through Yet ?
Regards
Agriv8
Hi mate, no it hasnt, but i think my web online thingy is limited to 2MB!!!!! Virgin media for u, will cost my premium rate phone call to get it
upped.
I will U2U my unlimited work email addy.
Thanks
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
Moorron
|
| posted on 8/10/07 at 09:32 PM |
|
|
Update, getting urgent now.
Well, just took it for its mot. All was fine except it failed its emissions. Too rich i was told.
So i replaced the dizzy cap and rotor arm (again) and it didnt help. I'm a little stuffed now as the law is going to catch me out in a week or
so. What would cause a hotwire system to run rich??
I have checked the throttle pot and Co trim on the air flow meter and all seems fine. So that only leaves Ecu, fuel pressire regulator and fuel temp
sensors!
Any help?????
Sorry about my spelling, im an engineer and only work in numbers.
|
|
|
britishtrident
|
| posted on 9/10/07 at 07:28 AM |
|
|
Lucas Hot wire systems are generally very reliable although the Hitachi made hotwire air flow sensors dirfts off with age (idle gets richer over years
of use) when they do cause problem like most other MPi systems it is usually the coolant tempewrature sensor.
However if your engine has a dizzie -- if it is the type with the vac advance and the hall effect sensor built in to the dizzie the most likely
cause of trouble is the ribbion cable inside the dizzie this was a constant source of trouble on Rover SD1s.
[Edited on 9/10/07 by britishtrident]
[I] “ What use our work, Bennet, if we cannot care for those we love? .”
― From BBC TV/Amazon's Ripper Street.
[/I]
|
|
|
Moorron
|
| posted on 11/10/07 at 06:49 PM |
|
|
Yepee! its past it MOT!
Now the explaination. After a member here gave me a PDF on the Range rover ECU ( u r a star!), it explained some of its functions. After searching the
net for more info i came across some setting up help regarding the various pot sensors on the engine like the throttle pot and air flow meter. What i
gathered is the ECU reverts to the cat fuel map if it detects a fault on any of these sensors and therefore runs rich (limp home mode). I found the
air flow meter co2 trim value was way off, actualy reading 0.01V instead of the estimated 1.5V. Now i was confused as it said that the lower the volt
reading here the leaner the engine ran. But i still set it 'richer' to 1.5V.
After a few days driving it felt much better. Went to the MOT station today hoping it was ok and it was...just. What i think was happening is the co2
trim value was so low that the ECU thought it was faulty and set the cat map to run and so meant i was running rich (above 6% co2!).
just need to reset the timing and base idle and im done. 6 months of bad running, £250+ on parts, 14mpg instead of 16 lol, constant worry of it not
starting when i was out and about and 1 expert tuning sension with a local range rover garage! (they have lost a customer they could never have tuned
it or touched the co2 trim).
Thanks for the advice, ive learnt alot about EFI AND my range rover in the process.
|
|
|
