Hot starts

Hot starts

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Discussion

RB Will

Original Poster:

9,933 posts

247 months

Wednesday 5th May 2021
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Hi all

Still fairly new to the TVR experience so just after some opinions from those more experienced.

Got a 4.5. Starts absolutely fine from cold, bit slow but ok when warming but a bit of a massive struggle and sometimes failing when hot.

Is it a normal Cerb/ 4.5 thing that it is a lottery if you can get going again if trying to restart less than 5 mins after shutdown?

As far as I know (been told by seller) the car has a recent good battery, recent good starter and all electrics checked as ok.

When it is struggling/ failing it is like a car with a dead battery in that the engine just can’t turn over rather than spinning away and just not firing

gruffalo

7,685 posts

233 months

Wednesday 5th May 2021
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The newer starters from WOSP have a tighter fit on the gear that interfaces with the fly wheel.

The fix is a 1mm spacer between the starter and the bell housing then all is fine when hot and cold.

TwinKam

3,165 posts

102 months

Wednesday 5th May 2021
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Don't buy the spacer from them though... mine looked like it had been cut out with a knife and fork... on a moving train... in the dark!
Peter Essling does neat laser-cut ones that are cheaper too.

Penelope Stopit

11,209 posts

116 months

Wednesday 5th May 2021
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RB Will said:
When it is struggling/ failing it is like a car with a dead battery in that the engine just can’t turn over rather than spinning away and just not firing
Do you mean that there's no response from the starter motor when pressing the start button or that the starter cranks the engine over slowly?

CerbWill

681 posts

125 months

Thursday 6th May 2021
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There are some cheap rubbish starter motors about. As Gruffalo says WOSP are good. But before you go spending hundreds on a new starter check the heatshield is fitted. Without it the nearside exhaust manifold cooks the starter. Also, what battery is fitted? I know you said it's new but good batteries make a difference. I have an Optima Red Top and spins the engine over faster than a spare Exide I have that used to be fitted to the Cerb.

On the electrics front, what was checked? Condition and size of the battery to starter cable makes a difference. How is it unearthed? Mine has an earth cable from one of the starter mounting bolts back to the battery. I thought that was standard until a previous discussion on PH. Otherwise it'll earth through the engine earth strap so if that's in poor condition it won't help.

Edited by CerbWill on Thursday 6th May 07:15

RB Will

Original Poster:

9,933 posts

247 months

Thursday 6th May 2021
quotequote all
Penelope Stopit said:
Do you mean that there's no response from the starter motor when pressing the start button or that the starter cranks the engine over slowly?
There is a response to pressing the button, so that is ok. It is just that it really struggles to turn it over. Feels like it does half a revolution then gets stuck, then manages to build up to doing another one, rather than a steady slow turnover.

Thanks for the thoughts everyone. Spacer sounds like a good idea and I’ll check if the heat shield is there.

As for the electrics I’ve been told by the previous owner everything possibly related has been checked and or replaced. The only thing he didn’t get round to sorting was the starter motor itself. It has just had a new I think WOSP starter and new cable from the battery to starter put on it last week but seems to have made no improvement, if anything it was worse.

So maybe heatshield and spacer are the answer.

If they don’t work I guess I have bigger things to worry about. Though I’ve never known an engine get tight and hard to spin when not massively overheating.


Penelope Stopit

11,209 posts

116 months

Thursday 6th May 2021
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RB Will said:
Penelope Stopit said:
Do you mean that there's no response from the starter motor when pressing the start button or that the starter cranks the engine over slowly?
There is a response to pressing the button, so that is ok. It is just that it really struggles to turn it over. Feels like it does half a revolution then gets stuck, then manages to build up to doing another one, rather than a steady slow turnover.

Thanks for the thoughts everyone. Spacer sounds like a good idea and I’ll check if the heat shield is there.

As for the electrics I’ve been told by the previous owner everything possibly related has been checked and or replaced. The only thing he didn’t get round to sorting was the starter motor itself. It has just had a new I think WOSP starter and new cable from the battery to starter put on it last week but seems to have made no improvement, if anything it was worse.

So maybe heatshield and spacer are the answer.

If they don’t work I guess I have bigger things to worry about. Though I’ve never known an engine get tight and hard to spin when not massively overheating.
Sluggish starter then

As above, starter pinion could be tight to the flywheel (expansion when hot causing the problem)

If the pinion to flywheel meshing is ok, check battery voltage and then voltage at the starter during cranking

0.75 volts maximum volt-drop from battery positive to the starter main positive supply during cranking

0.25 volts maximum volt-drop from battery negative to the starter body during cranking

gruffalo

7,685 posts

233 months

Thursday 6th May 2021
quotequote all
Penelope Stopit said:
Sluggish starter then

As above, starter pinion could be tight to the flywheel (expansion when hot causing the problem)

If the pinion to flywheel meshing is ok, check battery voltage and then voltage at the starter during cranking

0.75 volts maximum volt-drop from battery positive to the starter main positive supply during cranking

0.25 volts maximum volt-drop from battery negative to the starter body during cranking
With mine it struggles to mesh and when it does I get the symptoms above.

New starter from WOSP and when cold has absolutely now problems at all.

I have a shim on its way to me from Peter which I will fit at the weekend.


Penelope Stopit

11,209 posts

116 months

Thursday 6th May 2021
quotequote all
gruffalo said:
Penelope Stopit said:
Sluggish starter then

As above, starter pinion could be tight to the flywheel (expansion when hot causing the problem)

If the pinion to flywheel meshing is ok, check battery voltage and then voltage at the starter during cranking

0.75 volts maximum volt-drop from battery positive to the starter main positive supply during cranking

0.25 volts maximum volt-drop from battery negative to the starter body during cranking
With mine it struggles to mesh and when it does I get the symptoms above.

New starter from WOSP and when cold has absolutely now problems at all.

I have a shim on its way to me from Peter which I will fit at the weekend.
If there is such a thing as a good fault, this is one

Anyone not knowing about the possibility of tight meshing could easily be bamboozled

gruffalo

7,685 posts

233 months

Thursday 6th May 2021
quotequote all
Penelope Stopit said:
If there is such a thing as a good fault, this is one

Anyone not knowing about the possibility of tight meshing could easily be bamboozled
biggrinbiggrinbeer

Byker28i

67,983 posts

224 months

Thursday 6th May 2021
quotequote all
CerbWill said:
There are some cheap rubbish starter motors about. As Gruffalo says WOSP are good. But before you go spending hundreds on a new starter check the heatshield is fitted. Without it the nearside exhaust manifold cooks the starter. Also, what battery is fitted? I know you said it's new but good batteries make a difference. I have an Optima Red Top and spins the engine over faster than a spare Exide I have that used to be fitted to the Cerb.

On the electrics front, what was checked? Condition and size of the battery to starter cable makes a difference. How is it unearthed? Mine has an earth cable from one of the starter mounting bolts back to the battery. I thought that was standard until a previous discussion on PH. Otherwise it'll earth through the engine earth strap so if that's in poor condition it won't help.

Edited by CerbWill on Thursday 6th May 07:15
I second all this, along with the spacer. Heat shield is there for a reason but I've seen some cars with them missing
My red top spins the new starter much faster.
Also when I got the car back from the engine refit, I had all sorts of electrical issues, including starting. I found the earth lead from the battery to chassis and chassis to starter were frayed down to just a few threads, but looked good until you moved it. The Indy put back a duff cable rather than replace both at £30ish...

pmessling

2,294 posts

210 months

Thursday 6th May 2021
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I have a good
handful of shims left over should anyone else need one.


RB Will

Original Poster:

9,933 posts

247 months

Thursday 6th May 2021
quotequote all
Are you able to supply the heatshield pictured too just in case that is missing?
Is that what the factory one looks like or is it just a basic metal plate cover?

pmessling

2,294 posts

210 months

Thursday 6th May 2021
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No I don't have the heat shields but you can buy jackets to fit. That's what I done as mine was missing. Send me an email if you want the shim.

Ri Orus2

147 posts

169 months

Thursday 6th May 2021
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I would be glad of the shim if there are some going spare. Not intending to hijack the thread however, so if there are others need them more urgently then that's understandable. I have sent a pm anyway, just in case. Cheers.

pmessling

2,294 posts

210 months

Thursday 6th May 2021
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Should anyone else wants one I have two left.

TwinKam

3,165 posts

102 months

Thursday 6th May 2021
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Pics of your standard starter motor heat shields, please Chaps, mine has none.
I do prefer the idea of a 'shield' (which allows air flow) to a jacket' (which doesn't).

pmessling

2,294 posts

210 months

Thursday 6th May 2021
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The jacket I had worked well. Unfortunately the outside foil didn't last very well. But it did make a difference as I had the hot start issue prior to the shim.

Imran999

353 posts

160 months

Thursday 6th May 2021
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I have these symptoms too.
Factory starter motor, which works just fine when cold and mostly, when hot.
Occasionally, on an >30degC day, it will hesitate (pause mid cycle) and then continue, or once, it just refused to do anything for a few mins, until it had cooled down I suppose.
Mine does have the heat shield fitted - a silver rectangular foil board that has been bent into a u shape and held onto the starter with circular clip. But, it sits on top of the starter, protecting the top and sides - I always assumed it was preventing water from getting in to the starter (from the scuttle above). But perhaps the sides offer heat protection from the manifolds.

FarmyardPants

4,173 posts

225 months

Friday 7th May 2021
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pmessling said:
Should anyone else wants one I have two left.
I'll take one Peter if you still have any. Thanks!