Strange hot start problem
Discussion
Hi guys I'm familiar with the classic "hot start" problem we Griff/Chim owners experience. I had this 2 years ago and had HF Solutions replace my meta immobiliser and all has been well until last week. Up to recently the car started on the button and continued to restart when hot. However on two occasions in this last week I haven't been able to restart when hot. When this happens the fuel pump primes but after the pump stops it is followed by a weird chattering/squirting sound coming from the area of the fuel pump which lasts for around 2 seconds. The starter motor then won't activate and I can't even hear the starter solenoid clicking in. If I wait for a minute and try to start the fuel pump primes but this strange chattering/squirting sound disappears and the car will start normally.
I replaced the Bosch fuel and ECU relays 2 years ago and as said earlier the Meta immob was replaced around the same time.
This chattering/squirting noise I describe sounds to me a bit like it could be fuel de-pressurising. Does the pump have a non-return valve that maintains pressure until normal running conditions commence?? If this non-return valve leaked the pressure back to the tank would the ECU then disable the starter??
Any suggestion/help would be appreciated
I replaced the Bosch fuel and ECU relays 2 years ago and as said earlier the Meta immob was replaced around the same time.
This chattering/squirting noise I describe sounds to me a bit like it could be fuel de-pressurising. Does the pump have a non-return valve that maintains pressure until normal running conditions commence?? If this non-return valve leaked the pressure back to the tank would the ECU then disable the starter??
Any suggestion/help would be appreciated
I was getting some funny gurgles and thumps from my back end but have now cut a small 3mm section out of the fuel cap seal to allow tank to vent better. No more noises, although I should really look at the carbon canister enviroeu thingy and its plumbing. No clue if it would stop it starting sorry.
In an ideal world there is a one way valve on the output of the pump, so once the fuel line is pressurised it will stay like that for some time if you dont start the car, but even without the valve the system pressurises so quickly it wont stop the car starting anyway. The only thing I can think of that gurgles is the fuel return from the fuel regulator to the tank, so if you have fuel vaporization in the fuel rail you could hear the gas as the goes back into the tank. The 14CUX has a way of dealing with vapour lock by increasing the injector period depending on the fuel rail temp. It might be worth getting a reading of the temp with RoverGauge or an ECU mate to check the readings are sensible. None of this makes any sense with the starter not engaging however unless you have a fundamental 12 volt supply problem.
Thanks for the input. I don't think it's bad wiring to the starter because when starter does get engaged after the ~ 1 minute has lapsed it is turning the engine over at normal cranking speed. In other words it's either working or it isn't - there isn't a midway case of low starter torque.
Also the whining gurgling sound always co-incides with the starter not activating. Can't help but feel that the ECU for whatever reason is the blocking factor here.
One further point is that when I shut the engine down before the problem arises; the fans were still running. A feature of our cars is that turning off the ignition immediately cuts the fans. Could it be that this would cause a heat build up around the heads that would cause the fuel in the rails to vaporise??
I've got the Rover Gauge kit but never used it before so will take a look soonish.
Any further ideas please keep me posted. Cheers
Also the whining gurgling sound always co-incides with the starter not activating. Can't help but feel that the ECU for whatever reason is the blocking factor here.
One further point is that when I shut the engine down before the problem arises; the fans were still running. A feature of our cars is that turning off the ignition immediately cuts the fans. Could it be that this would cause a heat build up around the heads that would cause the fuel in the rails to vaporise??
I've got the Rover Gauge kit but never used it before so will take a look soonish.
Any further ideas please keep me posted. Cheers
Any chance this is two separate faults? Tank isn't vented right or the fuel is vapourised hence gurgling from your rear, and the starter or solenoid or summat is on it's way out so when the engine bay is super-hot it won't turn over? If the 'bay is cooler, engine starts and you'll never hear the tank sounds over the noise of the engine even if the fuel is still too hot?
Could be the armature in the solenoid of the starter motor sticking when it's hot...
As the main starter contacts are closed by this solemoid action it appears that the starter is 'just not working'.
I had this problem on my Griff many years ago. Cleaned up the solenoid armature and coil and fitted a heat shield blanket around the starter. No more problems - even at Le Mans summer heatwave temperatures...
If you need more details - PM me.
As the main starter contacts are closed by this solemoid action it appears that the starter is 'just not working'.
I had this problem on my Griff many years ago. Cleaned up the solenoid armature and coil and fitted a heat shield blanket around the starter. No more problems - even at Le Mans summer heatwave temperatures...
If you need more details - PM me.
Thanks that's useful. I've ordered a new starter this afternoon. Let's see if that cures it. BTW I have tracked the gurgling to vapour coming back along the fuel return. As suggested earlier this appears to be separate but coincidental to the starter/solenoid issue. I need to get around to getting Rover Gauge looking at that. Thanks again to you guys.
I had similar issue, replaced immobiliser, both starter cables, new battery and the relay; no difference whatsoever.
I then fitted a new starter motor.....totally fixed. Never failed once.
The starter solenoid has the contacts inside that feed power to the main starter coils as the solenoid slides out and compresses them together. The combination of these contacts getting arc and temp corroded and the solenoid getting fried by the exhaust were stopping it working when hot.
As soon as it happens next time (which it will) I will just fit a new starter motor. £130 fitted at Torque RVT.
I then fitted a new starter motor.....totally fixed. Never failed once.
The starter solenoid has the contacts inside that feed power to the main starter coils as the solenoid slides out and compresses them together. The combination of these contacts getting arc and temp corroded and the solenoid getting fried by the exhaust were stopping it working when hot.
As soon as it happens next time (which it will) I will just fit a new starter motor. £130 fitted at Torque RVT.
Plan B said:
I replaced the two Bosch relays in the footwell spaghetti which I believe switch in the fuel pump and the ECU - is there another relay between the ignition switch and starter relay?
Let's hope the new starter motor solves the problem.........
Flying in the face of automotive wiring best practice TVR in their wisdom decided they didn't need to fit a relay in the starter solenoid circuit, preferring instead to rely on one of the two tiny relays (one high amp and one low amp)inside the Meta immobiliser. To compound the problem TVR then wired the low amp ECU through the high amp Meta relay and the high amp starter solenoid through the low amp Meta relay Let's hope the new starter motor solves the problem.........
This results in the the contacts on low amp relay inside the Meta immobiliser becoming burnt and pitted, and because this little relay serves the starter solenoid circuit the end result is often silence when you try to start the car. This usually first happens when the car is hot because as we all know resistance in any circuit increases with heat hence the term "Hot Start Fault".
At this point you can retrospectively add a relay (The Hot Start Kit) which on the face of it is a good idea, but what often gets overlooked is this new relay can't magically repair the already pitted and burnt contacts on the relay inside the Meta unit. The relay damage has already been done and is irreversible, only a new correctly wired Meta unit or a bypass of the existing failing unit will deliver a permanent fix.
The way TVR wired the Meta system is the reason why a cottage industry formed around replacing the alarm/immobiliser on these cars, Carl Baker & David at HF solutions between them must have sorted hundreds of Chims & Griffs in this respect over the years. Most cars will have been sorted by now but surprisingly I still get at least one email a month asking for my immobiliser bypass instructions which to date I've shared with over 100 TVR owners.
Your Meta system has been replaced by someone who knows these cars and the school boy wiring errors made by TVR, I'm sure David of HF solutions will have wired the new Meta unit correctly, IE low amp ECU through low amp Meta relay and high amp starter solenoid through high amp Meta relay.
I'd also like to think at the same time he followed automotive wiring best practice and added a dedicated starter solenoid relay to protect the contacts in the ignition switch, but you may want to check this with him.
Given you've already had the Meta system replaced by a respected TVR alarm specialist you may be tempted focus your suspicions on the starter motor itself, or more specifically the starter solenoid. But before you do, consider the other known issue on these cars is the feeble battery to starter cable used by TVR. This cable is very long and the gauge used by TVR was at best marginal from new, after 15 years or more of being cooked it becomes internally corroded and so its resistance increases significantly, and again especially when hot. Normally what you experience here is a slow turning starter motor but if its really bad it can result in the starter not turning at all.
So the truth is there were a number faults introduced by TVR from the get go that meant guaranteed unreliable starting was effectively hard wired into all Chimaeras & Griffs from new, when you replace the Meta system and wire it correctly you're really just solving one of these faults. At this point adding in the dedicated starter relay TVR neglected to fit from new plus a new beefier starter cable and a direct earth return should not be viewed as a single solution in isolation but will all make their own incremental improvements that each combine to deliver a reliably starting car.
None of the above of course will fix a cooked starter motor but avoid falling into the trap of making assumptions and trying to fix the problem by simply replacing components in the blind hope you'll stumble on a solution, what you should do is use your test meter to conclusively identify the faulty component.
After that is about combination of improvements to sort out what TVR gave us, and for sure if you've gone to the trouble and expense of sorting the Meta issue I would strongly encourage you to renew and upgrade the very weedy original starter cable and add in that earth return cable too.
Make sure David at HF solutions gave you a dedicated starter relay and make sure it's functioning correctly if he did, then and only then turn your attentions to testing the starter motor.
Edited by ChimpOnGas on Tuesday 10th May 08:21
ChimpOnGas said:
Plan B said:
I replaced the two Bosch relays in the footwell spaghetti which I believe switch in the fuel pump and the ECU - is there another relay between the ignition switch and starter relay?
Let's hope the new starter motor solves the problem.........
Flying in the face of automotive wiring best practice TVR in their wisdom decided they didn't need to fit a relay in the starter solenoid circuit, preferring instead to rely on one of the two tiny relays (one high amp and one low amp)inside the Meta immobiliser. To compound the problem TVR then wired the low amp ECU through the high amp Meta relay and the high amp starter solenoid through the low amp Meta relay Let's hope the new starter motor solves the problem.........
This results in the the contacts on low amp relay inside the Meta immobiliser becoming burnt and pitted, and because this little relay serves the starter solenoid circuit the end result is often silence when you try to start the car. This usually first happens when the car is hot because as we all know resistance in any circuit increases with heat hence the term "Hot Start Fault".
At this point you can retrospectively add a relay (The Hot Start Kit) which on the face of it is a good idea, but what often gets overlooked is this new relay can't magically repair the already pitted and burnt contacts on the relay inside the Meta unit. The relay damage has already been done and is irreversible, only a new correctly wired Meta unit or a bypass of the existing failing unit will deliver a permanent fix.
The way TVR wired the Meta system is the reason why a cottage industry formed around replacing the alarm/immobiliser on these cars, Carl Baker & David at HF solutions between them must have sorted hundreds of Chims & Griffs in this respect over the years. Most cars will have been sorted by now but surprisingly I still get at least one email a month asking for my immobiliser bypass instructions which to date I've shared with over 100 TVR owners.
Your Meta system has been replaced by someone who knows these cars and the school boy wiring errors made by TVR, I'm sure David of HF solutions will have wired the new Meta unit correctly, IE low amp ECU through low amp Meta relay and high amp starter solenoid through high amp Meta relay.
I'd also like to think at the same time he followed automotive wiring best practice and added a dedicated starter solenoid relay to protect the contacts in the ignition switch, but you may want to check this with him.
Given you've already had the Meta system replaced by a respected TVR alarm specialist you may be tempted focus your suspicions on the starter motor itself, or more specifically the starter solenoid. But before you do, consider the other known issue on these cars is the feeble battery to starter cable used by TVR. This cable is very long and the gauge used by TVR was at best marginal from new, after 15 years or more of being cooked it becomes internally corroded and so its resistance increases significantly, and again especially when hot. Normally what you experience here is a slow turning starter motor but if its really bad it can result in the starter not turning at all.
So the truth is there were a number faults introduced by TVR from the get go that meant guaranteed unreliable starting was effectively hard wired into all Chimaeras & Griffs from new, when you replace the Meta system and wire it correctly you're really just solving one of these faults. At this point adding in the dedicated starter relay TVR neglected to fit from new plus a new beefier starter cable and a direct earth return should not be viewed as a single solution in isolation but will all make their own incremental improvements that each combine to deliver a reliably starting car.
None of the above of course will fix a cooked starter motor but avoid falling into the trap of making assumptions and trying to fix the problem by simply replacing components in the blind hope you'll stumble on a solution, what you should do is use your test meter to conclusively identify the faulty component.
After that is about combination of improvements to sort out what TVR gave us, and for sure if you've gone to the trouble and expense of sorting the Meta issue I would strongly encourage you to renew and upgrade the very weedy original starter cable and add in that earth return cable too.
Make sure David at HF solutions gave you a dedicated starter relay and make sure it's functioning correctly if he did, then and only then turn your attentions to testing the starter motor.
Edited by ChimpOnGas on Tuesday 10th May 08:21
Carl Baker replaced my alarm system, thoroughly recommend his knowledgeable services.
Seconded - great summary CoG. The new starter arrived today and this will get fitted after I come back from my blokes away weekend. You've prompted me to upgrade the feed and earth connections which on reflection I think I should do - as well as figuring out how I can best form a heat shield for the new starter.
tivver500 said:
Demon Tweaks sell a starter heat shield 'blanket' that is just wrapped around the starter and secured with some stainless steel wire.
Mines been on for 10+ years.......
The best thing you can do to remove heat from the starter motor is not to wrap it, but to reduce the excessive heat radiating onto it in the first place.Mines been on for 10+ years.......
To this end I highly recommend a full de-cat, this will not only drop exhaust temps by up to 50% but has also been shown to add anything from 10-15 horsepower depending on engine size.
It's a win win, and no starter motor wrapping required.
Finally, if your MoT tester won't pass the car without cats... change your MoT tester for one who will!
Protect your starter motor not the environment and give your TVR a performance boost too, the Dolphins will never catch you
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