Hot Start problem

Author
Discussion

jaydom

Original Poster:

179 posts

163 months

Tuesday 9th May 2023
quotequote all
Hello everybody and tvr's fans !

I got a problem with my T350 : it doesn't fire up when the engine is hot, knowing that the starter is a new one.

I have to wait nearly one hour to start it again.

I read several threads that are saying :
- "temperature protection" of the starter (what is it ? where to find it ?)
- Big fuse problem (I changed it less than on year ago)
- Coils

So it will help me a lot to get your opinions in order for me to solve this problem quite easily and fast !

Many thanks in advance,

Jerôme

NDA

22,335 posts

232 months

Tuesday 9th May 2023
quotequote all
Is the fuel pump working? Making the right noise?

Could be a relay - could also be fuel evaporation. Is cool fuel getting through from a full tank, or is the fuel a bit low?

Just random thoughts! smile

jaydom

Original Poster:

179 posts

163 months

Tuesday 9th May 2023
quotequote all
No worries with the fuel pump.

jaydom

Original Poster:

179 posts

163 months

Tuesday 9th May 2023
quotequote all
but thanks for your thoughts !

sixor8

6,609 posts

275 months

Tuesday 9th May 2023
quotequote all
What alarm and / or immobiliser system is fitted? This problem is extremely well know on Chimaera and Griffs with the Meta system being wired in incorrectly by TVR.

glow worm

6,170 posts

234 months

Tuesday 9th May 2023
quotequote all
Is it attempting to turn it over? But no umph... Mines started playing up too... with a new heavy duty starter (because it's a 4.5SS)... Sometimes I get away with it and it will catch . From cold it's like a machine gun no problems at all, but when hot it's really sluggish.

jaydom

Original Poster:

179 posts

163 months

Tuesday 9th May 2023
quotequote all
Thanks for all your replies

in fact, as you say, when cold, the new starter is a riot gun : less than two seconds, ant the engine fires up.

But when it's hot (engine hot), it looks like the starter is old, without strength, hesitating to turn and to launch itself, needing to get "fresh air"...

I was thinking about two points on my side :
- coil maybe tired (20 years old)
- a temperature sender (air, fuel ?)

That's why i ask the forum as I'm quite sure that this problem was existing before my experience

glow worm

6,170 posts

234 months

Tuesday 9th May 2023
quotequote all
That's why I think my problem is more a breakdown in the electrical supply to the starter motor when hot. I don't know if a fuse or diode can be affected by heat causing a voltage/amperage drop to the starter but starter power seem to be lost somewhere.

m4tti

5,466 posts

162 months

Tuesday 9th May 2023
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Pull all of the main earths and clean them up and replace, even if they look clean.

I had this, temperature related resistance

Basil Brush

5,227 posts

270 months

Wednesday 10th May 2023
quotequote all
sixor8 said:
What alarm and / or immobiliser system is fitted? This problem is extremely well know on Chimaera and Griffs with the Meta system being wired in incorrectly by TVR.
I think it's the same on later cars with the immobiliser circuits being the wrong way round, load vs rating.

astonman

799 posts

217 months

Wednesday 10th May 2023
quotequote all
My car is perfect,hot or cold.Never been out in the rain( except original drive from dealer when new).
5490 miles from new.I suspect earth issues,due to corrosion.

nawarne

3,098 posts

267 months

Thursday 11th May 2023
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Hi Jerome,

Check 'easy' things first! - Battery - earths

If starter is fairly new then my prime culprit is the heavy gauge wire from the battery to the starter/100A fuse holder.
They degrade over time in the engine bay heat.

Nick

mk1fan

10,651 posts

232 months

Thursday 11th May 2023
quotequote all
nawarne said:
Hi Jerome,

Check 'easy' things first! - Battery - earths

If starter is fairly new then my prime culprit is the heavy gauge wire from the battery to the starter/100A fuse holder.
They degrade over time in the engine bay heat.

Nick
This. If the starter turns over fine when cold but too slowly when hot, then first checks are the power supply / wiring cables and connections. The fuel pumps and coil may well be defective AS WELL but they wouldn't make the starter turn slowly.

TVR undersized their starter and battery cables on all their cars. On the T cars they made a special effort to wire it up badly and run cables via all the hot spots. My Tamora had 16mm cables to the starter and the alternator. All were almost solid / really stiff when I changed them out last year. I fitted 25mm cables and made sure the new connectors were solidly done too. Relocated the alternator fuse (as well as swapping to a ceramic / midi type so you can reach it without having to take the airbox out at the same time.

Do the same for the earth cables too. No point only doing one side of the circuit.

jaydom

Original Poster:

179 posts

163 months

Thursday 11th May 2023
quotequote all
Great !

Thanks for all your answers.

I will check electric cables first (earth and power) and, if it's not the problem, il will check after all the coil.

Regards to all and everyone

Jerome

GaryF

974 posts

260 months

Saturday 13th May 2023
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Funny, I've started to notice the same with my Sag. Got it twice today when starting from hot. Sounds like the starter has no oomph but does then get the engine to turnover. Interested in what you find as your issue.

non_linear

297 posts

90 months

Sunday 14th May 2023
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jaydom said:
Great !

Thanks for all your answers.

I will check electric cables first (earth and power) and, if it's not the problem, il will check after all the coil.

Regards to all and everyone

Jerome
Could it be heat soak into the starter motor? Has this only started happening with the new motor, or was it there before? My T350 started badly when hot or cold with the original 1.4kW motor, but fitting a high power motor is the best improvement I have made to the car.

As others have said, if the starter motor is not turning over there is no point looking at the coil.

jaydom

Original Poster:

179 posts

163 months

Sunday 14th May 2023
quotequote all
Good point
It was doing the same before.
And that’s why i changed the starter btw.
20yo… it could have been the issue.
I will check all connections and the famous 100 amp fuse first

x 7usc

1,423 posts

202 months

Sunday 14th May 2023
quotequote all
nawarne said:
Hi Jerome,

Check 'easy' things first! - Battery - earths

If starter is fairly new then my prime culprit is the heavy gauge wire from the battery to the starter/100A fuse holder.
They degrade over time in the engine bay heat.

Nick
My money is in what Nick said, the battery to starter cable sounds very much like its breaking down, a cables resistance goes up when its hot too and copper adsorbs heat well. a visual inspection won't always show anything up but if the heat shroud around the cable is missing or torn in places that won't help. i would get a heavier duty cable made up and replace it to be sure, slide it in thermal sleeve to keep the heat away from the cable as much as possible, this also acts as an extra layer of protection against rubbing on the chassis too.

jaydom

Original Poster:

179 posts

163 months

Sunday 14th May 2023
quotequote all
💪💪💪
Il will check the cable first

But i guess your right

konrad.holl

267 posts

212 months

Sunday 21st May 2023
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Another hint: I had hot start problems too, a long time back. At the time it was a faulty water temparature sensor. I know there are two, but my procedure was unplugging the one under the air filter box:

  1. Remove the air filter housing top to access to temperature sensor
  2. Unplug the sensor
  3. Start the engine
  4. Put everything back together
  5. Off you go...
At some point I got a good sensor (I think the 3rd or 4th new one) - no problems since.