Jump to content


Photo
- - - - -

Starter Motor Or Battery?


  • Please log in to reply
6 replies to this topic

#1 Arthy

Arthy

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 65 posts
  • Location: Birmingham

Posted 10 May 2018 - 08:27 PM

Hi guys!

 

Since my engine rebuild to fast road spec, cold starting has been difficult. The engine struggles to turn over which it seems like a flat battery. The battery in my car hasn't been used for 6 months but I have charged it a bit before using it again.

 

I have to jump start it from cold, but even then it struggles to turn it over but it's just enough! (The jump battery could do with a charge though!)

 

I'm starting to think it's a weak starter motor due to the new/high compression engine? Would a standard pre-engaged starter be enough to start it? 

 

So I'm either thinking of getting a new battery or high torque starter motor? OR it could be a bad engine earth or ignition timing? The car starts easily when warm though! 

 

Any help is appreciated! 

 

Arthur



#2 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 10 May 2018 - 08:29 PM

charging it a bit! what does that mean? get it on charge and dont try starting it till it is fully changed. then you might have an idea what is happening.



#3 Swift_General

Swift_General

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 805 posts
  • Location: England

Posted 10 May 2018 - 08:59 PM

What voltage is showing across the starter motor after a fully charged battery when cranking?

#4 Arthy

Arthy

    Stage One Kit Fitted

  • TMF+ Member
  • PipPipPip
  • 65 posts
  • Location: Birmingham

Posted 10 May 2018 - 09:11 PM

Sorry!! Forgot to mention the voltmeter is showing a solid 12v when ignition is on! I'll check what the voltage is across the starter tomorrow when turning over!

 

I just thought even with 2 batteries (albiet not fully charged) it would turn over easily? I'll give them a good charge tomorrow too! 



#5 Swift_General

Swift_General

    One Carb Or Two?

  • Members
  • PipPipPipPipPipPipPip
  • 805 posts
  • Location: England

Posted 10 May 2018 - 09:47 PM

I would expect a fully charged rested battery to be showing no less than 12.6v (no load). Check this, then voltage accros starter motor when cranking, and voltage accross battery when cranking (to determine any unusually high voltage drop).

#6 nicklouse

nicklouse

    Moved Into The Garage

  • TMF+ Member
  • PipPipPipPipPipPipPipPipPipPipPip
  • 10,069 posts
  • Location: Not Yorkshire

Posted 10 May 2018 - 10:48 PM



Sorry!! Forgot to mention the voltmeter is showing a solid 12v when ignition is on! I'll check what the voltage is across the starter tomorrow when turning over!

 

I just thought even with 2 batteries (albiet not fully charged) it would turn over easily? I'll give them a good charge tomorrow too! 

so almost flat. understand the condition of a battery. also have it drop tested (for how long it holds a charge).

Attached File  voltchart1.gif   6.43K   2 downloads



#7 timmy850

timmy850

    Camshaft & Stage Two Head

  • TMF+ Member
  • PipPipPipPipPipPipPipPip
  • 1,659 posts
  • Location: NSW, Australia
  • Local Club: MITG

Posted 11 May 2018 - 04:26 AM

Best way to check the battery it to take it to a battery shop and get them to do the load test on it. 






0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users

Mini Spares