Tacho is certainly suspect!
Discussion
When I first picked her up after driving a while, gently as not used to her and because it was ruddy awful wet and cold weather, noticed that the tacho did not seem to be working properly. If stationary in neutral you give it a rev it seems to work but not when driving unless driving with gusto then it seems to wake up. We had a dry afternoon before i left for the train/tunnel and took a friend out and we did get the needle to 5,000 rpm.
However on the drive through Europe it seemed to be not reading as it should again................................ see photos
Am told that the 3,000 mark is normal for 80 mph.
Trouble is mine is not even reading that at 90!
Other gauges seem to work fine.
Any ideas as to what we need to look at to get this working as it should?
However on the drive through Europe it seemed to be not reading as it should again................................ see photos
Am told that the 3,000 mark is normal for 80 mph.
Trouble is mine is not even reading that at 90!
Other gauges seem to work fine.
Any ideas as to what we need to look at to get this working as it should?
Can only assume that the plugs are correct for the new leads as Heath supplied and fitted both back in September when he was sorting her out for me.
OK just went out and pulled a plug and yes they are indeed NGK R BPR6ES
Had to find an old socket as never replaced my 14mm plug socket but as luck would have it found one of Dad's old long reach Whitworth ones that fit plugs.
OK just went out and pulled a plug and yes they are indeed NGK R BPR6ES
Had to find an old socket as never replaced my 14mm plug socket but as luck would have it found one of Dad's old long reach Whitworth ones that fit plugs.
Right now an a very unhappy chappie just started her up after refitting plug and lead and she hesitated then revved up on her own and then there was this horrible whining. So go a long screwdriver to listen to things with and found it without listening as as I put my hand on top of the alternator it almost burnt me. Am wondering if this may be effecting the tacho?
Damned bearings it seems are shot. So looks like a rebuild or replacement alternator. Just damned lucky it did not go on my drive down. Of course it's now Saturday afternoon so my plans for a little run out in her Sunday are dashed and cannot try to get one until Monday at least.
I find the date interesting as she was registered in July 93, dunno why I thought it was June!!! it's July 1993 so that 12 must be week number rather than month?
Damned bearings it seems are shot. So looks like a rebuild or replacement alternator. Just damned lucky it did not go on my drive down. Of course it's now Saturday afternoon so my plans for a little run out in her Sunday are dashed and cannot try to get one until Monday at least.
I find the date interesting as she was registered in July 93, dunno why I thought it was June!!! it's July 1993 so that 12 must be week number rather than month?
Sorry we have been down to the town for dinner.
Right to answer your questions:-
I did raise this matter with Mat on the Monday she got her new MOT and he tried it in his workshop and the tacho needle did swing up past 3000 andI have had it past 5000 once when showing her off to an old friend in Sussex. It is just not working as it should do!
Before we left I lifted the bonnet and put my hand on the alternator and it was still darned hot so I disconnected the battery and in doing so found the negative terminal bolt lose and a black wire not making proper contact. neither of these would help matters. This reminds me that I need to get a 100 amp fuse and new holder JIC!
Right to answer your questions:-
I did raise this matter with Mat on the Monday she got her new MOT and he tried it in his workshop and the tacho needle did swing up past 3000 andI have had it past 5000 once when showing her off to an old friend in Sussex. It is just not working as it should do!
Before we left I lifted the bonnet and put my hand on the alternator and it was still darned hot so I disconnected the battery and in doing so found the negative terminal bolt lose and a black wire not making proper contact. neither of these would help matters. This reminds me that I need to get a 100 amp fuse and new holder JIC!
Cannot see how disconnecting a terminal will help the bearings?
Anyway left the battery disconnected overnight and now it's reconnected there are no dash LED warning lights illuminating at all. The alternator is putting a charge into the battery if a little low at only 12.7 volts so am considering my options:-
1) buy a replacement from the UK an wait a week to 3 months for it to arrive (yes sometimes things can take that long)
2) Source a replacement locally.
3) Pull this one apart and see what condition it is inside and rebuild if possible.
4) Sell the Chimaera and buy something sensible!
Am going to have to pull all the fuses and check them to make sure none are blown now. She fires up and runs but that alternator starts heating up immediately and while connected to the battery does not seem to cool down unless disconnected. The two LED's top and bottom between the speedo and Tacho used to illuminate then one packed in after I swapped the stereo head unit, wonder if I pulled something off?, and now the other has packed in the centre yellow one is the oil pressure light which wa snot working but the spade connector had come off. Have put it back on and lamp is working now again.
Pulled all the fuses one at a time and found none blown.
Anyway left the battery disconnected overnight and now it's reconnected there are no dash LED warning lights illuminating at all. The alternator is putting a charge into the battery if a little low at only 12.7 volts so am considering my options:-
1) buy a replacement from the UK an wait a week to 3 months for it to arrive (yes sometimes things can take that long)
2) Source a replacement locally.
3) Pull this one apart and see what condition it is inside and rebuild if possible.
4) Sell the Chimaera and buy something sensible!
Am going to have to pull all the fuses and check them to make sure none are blown now. She fires up and runs but that alternator starts heating up immediately and while connected to the battery does not seem to cool down unless disconnected. The two LED's top and bottom between the speedo and Tacho used to illuminate then one packed in after I swapped the stereo head unit, wonder if I pulled something off?, and now the other has packed in the centre yellow one is the oil pressure light which wa snot working but the spade connector had come off. Have put it back on and lamp is working now again.
Pulled all the fuses one at a time and found none blown.
Well Anthony have disconnected battery again to be on the safe side and it's not as if am without a car after all just annoying however it is proof that cars don't like not being used. I think if this had been used more in the past the bearings would not have dried up then failed.
From my web searches it seems that this alternator was also used on some Massey Ferguson's and Fords as well and Land Rover's. Hopefully once replaced/repaired things will be better with a fully operational charging system once again.
From my web searches it seems that this alternator was also used on some Massey Ferguson's and Fords as well and Land Rover's. Hopefully once replaced/repaired things will be better with a fully operational charging system once again.
N7GTX said:
12.7v is not charging so each time you start the car the battery is draining further. If the battery is good it will recover overnight so long as the voltage does not get too low. Nominal battery voltage is 12.6v on a good battery - 2.1v per cell x 6.
Best to disconnect it altogether as QBee says, as alternators are prone to discharging batteries if the regulator has failed. The ignition warning LED not working means there is a break within the alternator regulator.
The comment above about disconnecting the wire was to see if this made a difference to the tacho reading, not the alternator.
For peace of mind I would be fitting a good quality one - fit and forget.
I am as certain as can be that your Alternator has a faulty rectifier, the field diodes will have gone short circuit and when that happens they put a permanent supply onto the rotor which will overheat more so when stood still
When the field diodes go short circuit there is a voltage being applied to the alternator warning light cable all the time rather than when the alternator is turning, when there is a voltage at the warning light terminal there may be some dash lights that are being extinguished by that voltage, those warning lights that may be being extinguished are the same ones that are normally extinguished when the alternator is turning and charging
Thank you both your comments have been noted. It is odd how this all seems to happened at once:-Best to disconnect it altogether as QBee says, as alternators are prone to discharging batteries if the regulator has failed. The ignition warning LED not working means there is a break within the alternator regulator.
The comment above about disconnecting the wire was to see if this made a difference to the tacho reading, not the alternator.
For peace of mind I would be fitting a good quality one - fit and forget.
Edited by N7GTX on Sunday 22 April 11:11
I am as certain as can be that your Alternator has a faulty rectifier, the field diodes will have gone short circuit and when that happens they put a permanent supply onto the rotor which will overheat more so when stood still
When the field diodes go short circuit there is a voltage being applied to the alternator warning light cable all the time rather than when the alternator is turning, when there is a voltage at the warning light terminal there may be some dash lights that are being extinguished by that voltage, those warning lights that may be being extinguished are the same ones that are normally extinguished when the alternator is turning and charging
Noisey bearings
Regulator
Probably diode .................................. all failing at the same time. Nearly 25 years is quite good but when one considers the low miles it is not so good really. We will know more tomorrow with any luck and am really wondering if new clean connections along with proper charging may indeed help the tacho issue.
Might be time to change the headlight bulbs to the new Osram Nightbreakers I bought last week locally.
wuckfitracing said:
Just a quick question, your speedo is reading 80 MPH, what speed are you actually doing, did you have a sat nav running at the same time. Did it read 70ish on the sat nav ?
Yes had the sat-nav running with speed set to KMH in Europe but MPH in the UK and speedos and sat-nav agree with one and other so speedo is quite accurate in it's reading.Classic Chim said:
I’m sure nursing it as you do when it’s all new is great.
Have you floored it and revved it’s head off yet.
Does it feel quick. These are the questions we need answering
Be blinking careful out of corners though!
Well yes have used the acceleration a few times in fact we had adry afternoon when I took a friend out in her he told me that he saw the sat-nav say 109 and ddi see over 5000 rpm on the tach once I think that the rev limiter even cut in though not sure as it might have been a fault.Have you floored it and revved it’s head off yet.
Does it feel quick. These are the questions we need answering
Be blinking careful out of corners though!
Also saw 160 on the sat-nav in Germany.
Classic Chim said:
Yes I agree. Brave indeed.
Hopefully he’s getting over the shock.
Driving one of these for an afternoon will knock most people about let alone with little experience of the car itself. The weather was a disgrace but showed the car can handle the rain water. Not the roof of course but electrics seem good and they often are on these cars considering the age now.
It’s really good to see he wants to drive it when he can’t sorry Brit but we’ve all been there 
You forget that although may be new to TVR's am not new to sports cars of this period. In fact have driven thousands of miles in the MGF's. The alternator packing in like this is a little bit of a shock an annoying little set back in fact. If the factors in the local town cannot help then guess next place to try is "Wildrovers" the Land Rover specialist not too far from here.Hopefully he’s getting over the shock.
Driving one of these for an afternoon will knock most people about let alone with little experience of the car itself. The weather was a disgrace but showed the car can handle the rain water. Not the roof of course but electrics seem good and they often are on these cars considering the age now.
It’s really good to see he wants to drive it when he can’t
sorry Brit but we’ve all been there Penelope Stopit said:
You should replace that needle roller bearing as they do wear
If you do take my advice and replace the roller bearing you will need to use a press to push it out, you will also need a socket from your tools socket set or a tube that has a hole in it slightly bigger than the roller, what you do is place the slip-ring end shield over the supported socket in a position so that the alloy in its center very close to where it holds the roller is fully supported, now the roller can be pressed out from the outside inwards using another socket or tube slightly smaller than the roller
If you don't support the end shield very close to the roller the whole end shield will break into bits rather than the roller pushing out when you use the press
No press or access to one. Actually have no workshop facilities at all really at present. No bench or vice just the tools we brought with us here. The bench and vice never made it. At the moment still have no roof over what will be the garage and car storage. She has only done a few miles really she clocked over to 38k on my drive down.If you do take my advice and replace the roller bearing you will need to use a press to push it out, you will also need a socket from your tools socket set or a tube that has a hole in it slightly bigger than the roller, what you do is place the slip-ring end shield over the supported socket in a position so that the alloy in its center very close to where it holds the roller is fully supported, now the roller can be pressed out from the outside inwards using another socket or tube slightly smaller than the roller
If you don't support the end shield very close to the roller the whole end shield will break into bits rather than the roller pushing out when you use the press
Penelope Stopit said:
In that case I shouldn't be advising at all
I've been there done that, this is really difficult for you, "what a bad time to have this problem"
You will very likely need to get someone to loosen the pulley nut off, sometimes they are extremely tight
Indeed it was but luckily it has an allen key hex in the shaft and I used that to undo the nut. Had the pulley off this morning and the casings apart which is how I cleaned out the old grease and applied new to the rear needle bearing. Tomorrow will have t get some solder as don't know what happened to mine in the move. The builder has told me of a company that does these rebuilds in Veliko Tarnovo the city that's about 28km away so if it comes to it can go there but had already ordered the parts by then. The builder is supposed to be putting the membrane on the timbers ready for the battening for the tiles thne putting in the two uprights for the 3 meter wide doors to the enclosed barn that is going to be home to the TVR.I've been there done that, this is really difficult for you, "what a bad time to have this problem"
You will very likely need to get someone to loosen the pulley nut off, sometimes they are extremely tight
Once this is all done can then think about building a bench and moving my tool chests into it and get some shelving up. The original plan was for a 2 post lift but the extra materail and work to support and stabilise the walls have eaten up the funds for that.
An interesting development here. I put the alternator back on this morning to see if greasing the rear bearing had made any difference to the noise and heat. Indeed it has improved things the odd thing is that on fully reconnecting and starting the engine it was not putting out 14.3 volts not the 12.7 of before. So drove her into town to collect the bits and pay the electric bill.
The tacho is more stable and coming home I gave it "some beans" in third and saw the needle touch the yellow blocks on the dial. The alternator is still whining but not as bad once she cools down will remove and rebuild it as planned and it will be very interesting to see what difference this makes now. Also bought some electrical solder, they sell it off the roll by the metre!!! and a new electric soldering iron as do not know where mine is ATM a whole £5:30 for the 40A mains one. " meters of solder was about 65p.
Oh yes at an indicated 110 the RPM's are 3,750 on the tacho.
The tacho is more stable and coming home I gave it "some beans" in third and saw the needle touch the yellow blocks on the dial. The alternator is still whining but not as bad once she cools down will remove and rebuild it as planned and it will be very interesting to see what difference this makes now. Also bought some electrical solder, they sell it off the roll by the metre!!! and a new electric soldering iron as do not know where mine is ATM a whole £5:30 for the 40A mains one. " meters of solder was about 65p.
Oh yes at an indicated 110 the RPM's are 3,750 on the tacho.
Well the alternator is partly rebuilt seems the new bearing was the wrong size and checking to original could find now play so put it back in with the other new bits. Bought a new electric soldering iron as don't know where mine is and 2 meters of solder. Result is a unit that now charges properly does not whine, was very careful the align the stator inside the body, and have a red ignition/charge light that once again works. Tacho seem more stable with only slight wavering of the needle at around 2500 rpm. Needle will now register rpm's above 3000 easily.
While running her up noticed that only the left hand radiator fan was running so checked the right and it was free and not seized then checked the plug and connections. Turned out fan is fine just dirty connections in the plug both rad fans now run as they should do and even in 30 degrees heat like this afternoon running while stationary the fans kept temp gauge at 80 degrees.
Discovered the dash top is not bolted down!!!
And this evening after a test run out found that there reversing light does not work. Bulb is OK so need to find and check the switch and fuse.
While running her up noticed that only the left hand radiator fan was running so checked the right and it was free and not seized then checked the plug and connections. Turned out fan is fine just dirty connections in the plug both rad fans now run as they should do and even in 30 degrees heat like this afternoon running while stationary the fans kept temp gauge at 80 degrees.
Discovered the dash top is not bolted down!!!
And this evening after a test run out found that there reversing light does not work. Bulb is OK so need to find and check the switch and fuse.
Edited by Brithunter on Wednesday 25th April 04:25
QBee said:
Mine isn’t bolted down either. Never found it worth the effort. If it bother you, try Velcro strips instead - from any haberdashers.....
Well it will make checking the connections to the dash LED's easier I suppose. Am sure both red ones used to illuminate but they stopped after the stereo head unit swapped so thought I had dislodged something. e now know of course that alternator wa son it's way out. The amber oil light and alternator charge light now both work again oil light was spade had come off switch. New regulator and rectifier has sorted the charge light.Penelope Stopit said:
Nicely done Brithunter, it's very interesting to know that the tacho is now behaving even though it's not driven by the alternator, it's all about volts, high volts, low volts, smooth volts and rough volts
Well it's certainly working now even if the needle does still wander around the 2500 rpm mark lower and higher in the range it behaves as one would expect. I will be checking behind the instruments for loose connections later when we investigate the no illuminating top red LED lamp.As to why TVR have such a problematic tacho has me wondering as other makes don't seem to have this problem. The one in my MGF behaves as one would expect and is stable no wavering about at all.
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