Chimaera will not start
Discussion
Hi all, new member and new TVR owner here,
I know this topic is a reoccurring one and there’s plenty of threads out there discussing it, but I’ve been looking for the answer and so far have been unsuccessful in getting to the bottom of it so was wondering if the kind and more experienced people on here would be able to help me in finding it.
Background of the car,
Bought in Jan (My first TVR after lusting after one for the best part of 10-15 years) from a guy that had it stood in a barn for about a year or so, couldn’t afford a mint one so went for the best example I could afford (I’m hands on, Far from a pro but I can usually get by with the help from forums and a willingness to learn)
I bought it despite the fact when I came to view it, it developed a misfire once it warmed up, which got worse with temperature and eventually became un-drivable on the test drive. The guy did have a ramp in this barn though, so managed to get a good look under it to find the chassis and outriggers where in pretty good nick still on original out riggers. This was my main concern on a car of this age and price point, a job I accept I may have to complete in the future but was hoping to get a few years of enjoyment out of it before attempting such a task. so took a bit of a gamble on it and Trailered it home.
I Replaced the HT leads with thicker 8mm leads, got rid of the plug extenders and fitted insulating boots round the ends of the leads to protect from the heat from the exhaust. This fixed the miss firing issue with multiple proving runs round the block and the car drove spot on from cold and hot. Tidied the car up to get it ready for this weekend to take it out for its first proper outing now the suns come out, but went to fire it up on Friday and couldn’t get it started 😔.
Symptoms
Ignition comes on, but when attempting to reset immobiliser the fuel pump does not prime and there’s no starter when moving to the cranking position. Central locking and alarm appear to work fine but the immobiliser touch pad no longer has its red flashing led illuminating so Initially suspected the immobiliser.
Rather than just go ahead and start buying replacement parts I thought I’d do some investigating to narrow down the fault to the immobiliser, so found a schematic drawing of the fuel pump circuit and stripped out the dash in an attempt to trace the fault back.
Where I’m at now.
I’ve bench tested both fuel pump and ecu relays and both operate as they should.
I’ve tested voltages at the relay terminal’s and found the following.
ECU relay - Open with ignition on or off
Pins 30, 85 and 86 all have +12v on with ignition on or off
Both 87 pins are to ground with ignition on or off
Fuel pump relay - Open with ignition on or off
Pin 30 is +12v ignition on of off
86 and both 87 are to ground ignition on or off
85 is not connected to + or - ignition on or off.
I’ve tested the ignition switch and I’m getting +12v on the white cable when ignition is on and then +12v at fuse 12 and fuse is ok.
I loose where the cable goes after fuse 12 but I do not have +12v at pin 86 on the fuel pump relay.
The drawings I’ve found suggest the immobiliser is after the fuel pump relay and therefore I can’t see a reason it could interrupt the supply to the relay but this is where I have drawn a blank. There seems to be something between fuse 12 and the fuel pump relay. Could this be the secondary circuit on the immobiliser?
When I took the dash board off I noticed that someone had already been there before as cables have been cut and soldered together to connect the alarm control box. it looks like the original white plug had got hot and melted at some point so maybe that was the reason for the butchery.
For reference there is M99T2 alarm and m36T immobiliser fitted to the car. I have read about the back to front wiring on the immobiliser and this is wired in via the original connections so could still present a risk.
Is there anything that stands out in these symptoms that point to a known fault within this circuit? If not could anyone suggest where to go from here? Is it worth bypassing the immobiliser to prove that it’s not that? If so could someone send over the instructions on how to do so? Also does anyone have any schematics for the ignition/ fuel pump circuits that could help me identify the fault?
Any info would be appreciated as I’m now stuck and brain is fried from chasing my arse.
Email address is Jasonw_88@hotmail.com
Many thanks
I know this topic is a reoccurring one and there’s plenty of threads out there discussing it, but I’ve been looking for the answer and so far have been unsuccessful in getting to the bottom of it so was wondering if the kind and more experienced people on here would be able to help me in finding it.
Background of the car,
Bought in Jan (My first TVR after lusting after one for the best part of 10-15 years) from a guy that had it stood in a barn for about a year or so, couldn’t afford a mint one so went for the best example I could afford (I’m hands on, Far from a pro but I can usually get by with the help from forums and a willingness to learn)
I bought it despite the fact when I came to view it, it developed a misfire once it warmed up, which got worse with temperature and eventually became un-drivable on the test drive. The guy did have a ramp in this barn though, so managed to get a good look under it to find the chassis and outriggers where in pretty good nick still on original out riggers. This was my main concern on a car of this age and price point, a job I accept I may have to complete in the future but was hoping to get a few years of enjoyment out of it before attempting such a task. so took a bit of a gamble on it and Trailered it home.
I Replaced the HT leads with thicker 8mm leads, got rid of the plug extenders and fitted insulating boots round the ends of the leads to protect from the heat from the exhaust. This fixed the miss firing issue with multiple proving runs round the block and the car drove spot on from cold and hot. Tidied the car up to get it ready for this weekend to take it out for its first proper outing now the suns come out, but went to fire it up on Friday and couldn’t get it started 😔.
Symptoms
Ignition comes on, but when attempting to reset immobiliser the fuel pump does not prime and there’s no starter when moving to the cranking position. Central locking and alarm appear to work fine but the immobiliser touch pad no longer has its red flashing led illuminating so Initially suspected the immobiliser.
Rather than just go ahead and start buying replacement parts I thought I’d do some investigating to narrow down the fault to the immobiliser, so found a schematic drawing of the fuel pump circuit and stripped out the dash in an attempt to trace the fault back.
Where I’m at now.
I’ve bench tested both fuel pump and ecu relays and both operate as they should.
I’ve tested voltages at the relay terminal’s and found the following.
ECU relay - Open with ignition on or off
Pins 30, 85 and 86 all have +12v on with ignition on or off
Both 87 pins are to ground with ignition on or off
Fuel pump relay - Open with ignition on or off
Pin 30 is +12v ignition on of off
86 and both 87 are to ground ignition on or off
85 is not connected to + or - ignition on or off.
I’ve tested the ignition switch and I’m getting +12v on the white cable when ignition is on and then +12v at fuse 12 and fuse is ok.
I loose where the cable goes after fuse 12 but I do not have +12v at pin 86 on the fuel pump relay.
The drawings I’ve found suggest the immobiliser is after the fuel pump relay and therefore I can’t see a reason it could interrupt the supply to the relay but this is where I have drawn a blank. There seems to be something between fuse 12 and the fuel pump relay. Could this be the secondary circuit on the immobiliser?
When I took the dash board off I noticed that someone had already been there before as cables have been cut and soldered together to connect the alarm control box. it looks like the original white plug had got hot and melted at some point so maybe that was the reason for the butchery.
For reference there is M99T2 alarm and m36T immobiliser fitted to the car. I have read about the back to front wiring on the immobiliser and this is wired in via the original connections so could still present a risk.
Is there anything that stands out in these symptoms that point to a known fault within this circuit? If not could anyone suggest where to go from here? Is it worth bypassing the immobiliser to prove that it’s not that? If so could someone send over the instructions on how to do so? Also does anyone have any schematics for the ignition/ fuel pump circuits that could help me identify the fault?
Any info would be appreciated as I’m now stuck and brain is fried from chasing my arse.
Email address is Jasonw_88@hotmail.com
Many thanks
Just reading this was very reminiscent of a very similar problem I had with my 96 MK2 a while ago. The culprit was the immobiliser relay (mine is the META immobiliser) and after a bit of jiggery pokery with the immobiliser wiring, managed to bypass the immobiliser relay and now just have the fuel pump immobilised which I'm perfectly happy with.
Only found that out due to the excellent advice and helpful chaps on here....
Only found that out due to the excellent advice and helpful chaps on here....
Edited by THEDAVINATOR on Sunday 9th March 16:24
Belle427 said:
Odds on its the Immobiliser, your better off performing the bypass to confirm it.
I will dig out the bypass details and mail them to you, i know your a new member and its frowned upon but your description tells me your a genuine owner.
I think it was you who very kindly sent them to me. I would have forwarded them to him too, just didn't want to break any rules etc as this is obviously a bit of a grey area I will dig out the bypass details and mail them to you, i know your a new member and its frowned upon but your description tells me your a genuine owner.
But yes, the feeling of finally getting something you've lusted after for so long (my wait was about 16/17 years) is amazing.
Still makes me feel warm and fuzzy now, 18 months on (despite the running issues)....
I Appreciate the delicacy of the subject, I do have another user account that I set up around 2005 back when it was free to advertise classifieds on piston heads but I don’t use the email address anymore so set up another account as couldn’t seem to change from my old one. Thank you for sending me the info Izzy, will try the bypass some time this week and let you know how I get on.🤞. Thanks for the quick reply’s really appreciate it. Gutted I couldn’t take it out this weekend as I spent a lot of time prepping it to get it ready and was really looking forward to getting out in it. Just to add salt to the wounds I saw another chimaera out enjoying the sun while taking my boy to rugby this morning. Would have been a perfect opportunity to have two passing each other. Hopfully the bypass works!
Thank god for that! Now to create a more permanent fix and put everything back together again. Thanks so much for the quick reply’s and the info that was sent over to resolve this issue. I'd personally just leave it bypassed, one less thing to worry about.
Only issue is maybe the impact on insurance.
You can get plug and play kits to replace it if you were interested.
https://abacusalarms.co.uk/tvr-alarms.html
Only issue is maybe the impact on insurance.
You can get plug and play kits to replace it if you were interested.
https://abacusalarms.co.uk/tvr-alarms.html
I'm going to continue my examination of the M36T immobiliser at some point (life got in the way again recently).
As per the other immobiliser thread in the Chimaera section, the starter circuit is connected via a 10A rated relay instead of a 45A rated one.
There is an unused 45A relay on the M36T board so it's just a question of swapping a couple of pins on the connector to move the starter circuit to the 45A relay.
This should eliminate any hot start and dead start issues.
I'll report back with pics at a later date.
As per the other immobiliser thread in the Chimaera section, the starter circuit is connected via a 10A rated relay instead of a 45A rated one.
There is an unused 45A relay on the M36T board so it's just a question of swapping a couple of pins on the connector to move the starter circuit to the 45A relay.
This should eliminate any hot start and dead start issues.
I'll report back with pics at a later date.
Hopefully that works - and that information might be very helpful to other owners.
It's also worth putting in a relay to lighten the load through the immobiliser circuit, very simple to do, and with the right kit, it'll be much more reliable.
You can see my progress on this from page 7 of this thread:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
TVR wired the immobiliser with the fuel pump on the heavy circuit, and the starter motor solenoid on the lighter one - but as the solenoids get older, the internal mechanism gets stiffer/lazy, and requires more current to pull them in to make the connection to the main starter motor feed (the big red wire). But it's the immobiliser that fails under that strain.
If you implement a permanent bypass on that circuit, it's worth doing it with an in-line fuse rated at 20A or 25A (can't remember).
I was able to get my older Foxguard alarm refurbished with new relays and memory chip (I believe this is not possible with the Meta unit), but have left the bypass wiring in place ready to push a fuse into, in case it goes again (hopefully it will last another 30 years).
It's also worth putting in a relay to lighten the load through the immobiliser circuit, very simple to do, and with the right kit, it'll be much more reliable.
You can see my progress on this from page 7 of this thread:
https://www.pistonheads.com/gassing/topic.asp?h=0&...
TVR wired the immobiliser with the fuel pump on the heavy circuit, and the starter motor solenoid on the lighter one - but as the solenoids get older, the internal mechanism gets stiffer/lazy, and requires more current to pull them in to make the connection to the main starter motor feed (the big red wire). But it's the immobiliser that fails under that strain.
If you implement a permanent bypass on that circuit, it's worth doing it with an in-line fuse rated at 20A or 25A (can't remember).
I was able to get my older Foxguard alarm refurbished with new relays and memory chip (I believe this is not possible with the Meta unit), but have left the bypass wiring in place ready to push a fuse into, in case it goes again (hopefully it will last another 30 years).
OIC said:
I'm going to continue my examination of the M36T immobiliser at some point (life got in the way again recently).
As per the other immobiliser thread in the Chimaera section, the starter circuit is connected via a 10A rated relay instead of a 45A rated one.
There is an unused 45A relay on the M36T board so it's just a question of swapping a couple of pins on the connector to move the starter circuit to the 45A relay.
This should eliminate any hot start and dead start issues.
I'll report back with pics at a later date.
Are you sure its 45 Amp?As per the other immobiliser thread in the Chimaera section, the starter circuit is connected via a 10A rated relay instead of a 45A rated one.
There is an unused 45A relay on the M36T board so it's just a question of swapping a couple of pins on the connector to move the starter circuit to the 45A relay.
This should eliminate any hot start and dead start issues.
I'll report back with pics at a later date.
Seems awful high for an Immobiliser unit, just generally interested as I have never opened one.
Can't comment on the current rate in the immobiliser relays - but I do understand the relays are potted-in in the Meta system, so you can't get to them to repair/replace.
Something occurred to me on this one - @Jason, your description of how the footwell relays (ECU and fuel pump) are showing voltage made me wonder if they are wired up correctly. I don't know, but thought it might be worth triggering a mini investigation, because if they are wrong, you'll have a drain on the battery.
When I discovered my hot start kit was in poor shape, the wiring of it was wrong, the relay was constantly warm (even when the car had not been used for a day or two), I inadvertently discovered my battery drain.
I was given this information by Polly Grigora, and it made all the difference:
Top circuit works and is correct
Bottom circuit works and is incorrect, relay holds in until battery goes flat and will always remain warm to hot
Worth checking terminal numbers on relay being used due to relays having different terminal configurations
Something occurred to me on this one - @Jason, your description of how the footwell relays (ECU and fuel pump) are showing voltage made me wonder if they are wired up correctly. I don't know, but thought it might be worth triggering a mini investigation, because if they are wrong, you'll have a drain on the battery.
When I discovered my hot start kit was in poor shape, the wiring of it was wrong, the relay was constantly warm (even when the car had not been used for a day or two), I inadvertently discovered my battery drain.
I was given this information by Polly Grigora, and it made all the difference:
Top circuit works and is correct
Bottom circuit works and is incorrect, relay holds in until battery goes flat and will always remain warm to hot
Worth checking terminal numbers on relay being used due to relays having different terminal configurations
This information is potentially extremely helpful for owners with the Meta unit.
Can you replace both relays with higher rated relays?
Maybe you could offer your services to Chim and Griff owners who are experiencing issues. Coupling that with the relay for the starter solenoid, you’d be bringing the old girls back to new!
Can you replace both relays with higher rated relays?
Maybe you could offer your services to Chim and Griff owners who are experiencing issues. Coupling that with the relay for the starter solenoid, you’d be bringing the old girls back to new!
Well meaning but you are assuming that the relays are the problem area. I have replaced two Meta units both of which had faults other than the relays and considering how old the original Meta units are now not really surprising.
And for my factory fitted Meta the correct high current relay was used for the cranking circuit so not all immobilisers were incorrectly wired.
I eventually repaced the second Meta with a Sterling unit, about a third of the price and IMHO a far better device as by the addition of 1 relay it opens the boot remotely as well. I even sold the old Meta units on eBay that nearly covered the cost.
And for my factory fitted Meta the correct high current relay was used for the cranking circuit so not all immobilisers were incorrectly wired.
I eventually repaced the second Meta with a Sterling unit, about a third of the price and IMHO a far better device as by the addition of 1 relay it opens the boot remotely as well. I even sold the old Meta units on eBay that nearly covered the cost.
Might not be related but here is a link to a Thread about relays and what happened in my case with a Chim' issue.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Any chance you're electrics have got wet?
I've added a pic.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Any chance you're electrics have got wet?
I've added a pic.
Edited by lancepar on Wednesday 12th March 12:14
Loubaruch said:
Well meaning but you are assuming that the relays are the problem area. I have replaced two Meta units both of which had faults other than the relays and considering how old the original Meta units are now not really surprising.
And for my factory fitted Meta the correct high current relay was used for the cranking circuit so not all immobilisers were incorrectly wired.
I eventually repaced the second Meta with a Sterling unit, about a third of the price and IMHO a far better device as by the addition of 1 relay it opens the boot remotely as well. I even sold the old Meta units on eBay that nearly covered the cost.
That does sound like a more holistic solution - I like the idea of a remote boot opener that is integrated into the overall system, not a separate fob.And for my factory fitted Meta the correct high current relay was used for the cranking circuit so not all immobilisers were incorrectly wired.
I eventually repaced the second Meta with a Sterling unit, about a third of the price and IMHO a far better device as by the addition of 1 relay it opens the boot remotely as well. I even sold the old Meta units on eBay that nearly covered the cost.
lancepar said:
Might not be related but here is a link to a Thread about relays and what happened in my case with a Chim' issue.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
Any chance you're electrics have got wet?
I've added a pic.
I had a park switch that looked like that - I cracked it open once I'd ordered a new one...https://www.pistonheads.com/gassing/topic.asp?h=0&...
Any chance you're electrics have got wet?
I've added a pic.
Edited by lancepar on Wednesday 12th March 12:14
It's not time v cost viable to offer relay (or other component) replacement for these Meta units.
I'm just doing a friend a favour with his Chim misbehaving.
Hopefully the information I gather on the way will be helpful to other owners.
I quite fancy trying a security chip swap from a bust unit to a cheap replacement used one off Ebay.
Would save having to pay someone to reprogram the replacement to work with your alarm and fobs.
Obviously upgrading the whole alarm / immobiliser for a modern system would also be nice, but I quite like to see originality maintained in old cars where possible.
I'm just doing a friend a favour with his Chim misbehaving.
Hopefully the information I gather on the way will be helpful to other owners.
I quite fancy trying a security chip swap from a bust unit to a cheap replacement used one off Ebay.
Would save having to pay someone to reprogram the replacement to work with your alarm and fobs.
Obviously upgrading the whole alarm / immobiliser for a modern system would also be nice, but I quite like to see originality maintained in old cars where possible.
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