Griff won t start when hot.
Discussion
Known problem on early 500s was that the starter motor wasn't up to the job when hot - symptoms as you describe.
(I had a new one when I bought the car and no problems with the replacement - it was one of a series of things that unfortunately cropped up on the couple of test drives I had - all down to non-use by previous owners.)
(I had a new one when I bought the car and no problems with the replacement - it was one of a series of things that unfortunately cropped up on the couple of test drives I had - all down to non-use by previous owners.)
I think we are seeing two problems here. If the starter doesnt turn, then could be heat damaged starter.But if its turning over but not firing, different story. Iam sure somebody will confirm but is there not a fuel temperature sensor? Also my Griff sometimes will not fire if i hold onto the cranking,if i do just a short turn over, away we go. Maybe ignition switch.
Could be either as the other posts have said heat killing the starter motor – heat shield will help reduce this. Or it could be due to fuel percolation (don’t laugh but the old Renault 5 Turbo used to have an anti-percolation fan that ran after the engine was switched off to stop the fuel evaporating from the carb) The Tuscan Challenge cars have this happen sometimes, if you spin off the engine heat won’t allow the car to restart, you either wait for it to cool down or get a set of jumper leads plugged in. I think that CDL use to batteries in their cars to help stop this happening - though not that Steve or David seem to see much of the scenery !!
Frst thing is the GRiff does not have carbs... normally. Unless someone has fitted them.
If the car won't start (but engine turns over) when hot then this could be down to almost anything in the injection and ignition system. Possible candidates are ignition module, coil, dizzy sensor, ECU, any of the injection sensors and so on. The immobiliser can also play up.
The problem is that unless the car can be made to demo the fault it is very difficult to fault find as by the time you check the faulty bit, it has cooled down and behaves itself.
This type of fault can be very difficult to track down. You have my deepest sympathy.
Steve
www.tvrbooks.co.uk
If the car won't start (but engine turns over) when hot then this could be down to almost anything in the injection and ignition system. Possible candidates are ignition module, coil, dizzy sensor, ECU, any of the injection sensors and so on. The immobiliser can also play up.
The problem is that unless the car can be made to demo the fault it is very difficult to fault find as by the time you check the faulty bit, it has cooled down and behaves itself.
This type of fault can be very difficult to track down. You have my deepest sympathy.
Steve
www.tvrbooks.co.uk
Not sure how effective heat shielding the starter motor really is: surely most of the heat is conducted to the motor along from where it is clamped to the car. David Batty v. sceptical about shielding and suggests replacement motor. I have had "cooking" problems with my motor when hot and must replace it in due course. But will shielding make a difference?
Steve: any thoughts in your experience?
>> Edited by cutmonster on Friday 22 November 13:18
Steve: any thoughts in your experience?
>> Edited by cutmonster on Friday 22 November 13:18
Good idea basically. It does seem to help and costs so little. Rally design sell the shielding for around £5 so it is not expensive to do. Many specialists are now fitting it as a matter of course when replacing the starter.
I should say that in most cases when the motor is failing, it is too late and the motor need some TLC and then fitting the shield will prolong its life after it has been repaired. It may cure the problem in marginal situations but that is rare. BTW the manifolds that go past the motor reach 600-800F and that is a lot hotter than the bell housing gets by a long long way. .
Steve
>> Edited by shpub on Friday 22 November 13:29
I should say that in most cases when the motor is failing, it is too late and the motor need some TLC and then fitting the shield will prolong its life after it has been repaired. It may cure the problem in marginal situations but that is rare. BTW the manifolds that go past the motor reach 600-800F and that is a lot hotter than the bell housing gets by a long long way. .
Steve
>> Edited by shpub on Friday 22 November 13:29
david beer said: I think we are seeing two problems here. If the starter doesnt turn, then could be heat damaged starter.But if its turning over but not firing, different story. Iam sure somebody will confirm but is there not a fuel temperature sensor? Also my Griff sometimes will not fire if i hold onto the cranking,if i do just a short turn over, away we go. Maybe ignition switch.
The battery voltage drops while you're cranking the engine over. To compensate for this, the coil is normally powered through a ballast resister that drops the voltage to about 9 volts, and this is bypassed while the engine is cranking so the coil sees 10-11 volts i.e. more that usual, not less, while the engine is cranking.
If you had an under-spec battery, or a poor earth or main power connection, you could be getting an unusually high voltage drop while cranking which is causing a weak spark. Alternatively, the ballast short circuit may not be working. Either way could lead to the symptoms you described i.e. engine won't fire until the moment you stop cranking it. You could check for this by putting a spark trace (passive strobe) in the HT king lead and seeing how the spark strength varies. It should get stronger while cranking, not weaker.
Hope this helps,
Peter Humphries (and a green V8S)
david beer said: I think we are seeing two problems here. If the starter doesnt turn, then could be heat damaged starter.But if its turning over but not firing, different story. Iam sure somebody will confirm but is there not a fuel temperature sensor? Also my Griff sometimes will not fire if i hold onto the cranking,if i do just a short turn over, away we go. Maybe ignition switch.
Course if the starter motor is turning, but it is not starting, it's down to fuel or spark.
I recently had a no spark situation which was the start of either the coil or the ignition booster breaking down. (Replaced both c£60 for the parts.) This was an embarassing one because having got trailered all the way to The Garage, it turned out it wanted to spark! Doh!!!
I am not aware that TVRs are prone to fuel vaporisation, but some cars are (I remember a Spitfire many years back where a garage decided that a heat shield was falling off and was superfluous
- course it was well enough to drive of the forecourt and enough yards down the road for them to have locked up!!!) 
Thanks for all your advice, perhaps i should have made myself a bit clearer, the engine turns over fine but just will not start if i leave the car for 3 to 4 mins when hot.
I then have to wait another 4 to 5 mins until the engine cool down enough to start. I intend to hill climb this car in the new season so i must cure it,also at petrol stations it tends to get a bit embarassing.Any further help would be much appreciated.
I then have to wait another 4 to 5 mins until the engine cool down enough to start. I intend to hill climb this car in the new season so i must cure it,also at petrol stations it tends to get a bit embarassing.Any further help would be much appreciated.
broscombe said: Thanks for all your advice, perhaps i should have made myself a bit clearer, the engine turns over fine but just will not start if i leave the car for 3 to 4 mins when hot.
I then have to wait another 4 to 5 mins until the engine cool down enough to start. I intend to hill climb this car in the new season so i must cure it,also at petrol stations it tends to get a bit embarassing.Any further help would be much appreciated.
Does it idle but not start? Could be fuel evaporation n the fuel rail or a faulty coil or something like that. You can use a passive strobe to check what's happening with the ignition. If it's an ignition glitch, try wrapping a bag of frozen peas round the coil for a couple of minutes, if that cures it it is probably the coil breaking down. If it's fuel evaporation, you can lag the fuel rails to cure this. In theory, running the fuel pump for thirty seconds or so would probably flush the fuel rail out and coll it down, but of course it only runs for five seconds each time you switch on. Opening the bonnet will speed the process up too.
Cheers,
Peter Humphries (and a green V8S)
Hillclimbing where, by the way?
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