Hot start dragging - battery?

For all electrical questions; Alternators including fitment; Light connections/wiring; Instruments; Gauges; MFA; Heater blower (not coolant related) issues etc etc.
Forum rules
Hints, tips and guides for repair and modification - the FAQ section on the main website is worth checking first for information relating to common faults and technical help. Useful posts and guides will be added to the FAQ http://www.sciroccoregister.co.uk/scirocco-faq
Post Reply
frlrubett
Posts: 128
Joined: Sun Jan 13, 2019 8:46 am
fill in the right answer: 15
Location: LONDON

Hot start dragging - battery?

Post by frlrubett »

So this Rocco has a reconditioned engine. 1988 Scala 1.8. Cold start is perfect but the hot cranks very slowly, turns over once before sticking. Repeated attempts and the engine does fire.

Mechanic has said the battery (came with car two years ago) could be underpowered. What battery specs do you recommend?

Is there alternative things I could look at before I start putting new batteries in?


User avatar
GT_II
Posts: 522
Joined: Thu Feb 23, 2017 11:18 pm
fill in the right answer: 15
Location: Warwickshire

Re: Hot start dragging - battery?

Post by GT_II »

Easy starting with the engine cold and slow cranking when hot is not what I would expect from a weak battery. As for specs, the original battery was specified as 45Ah, 220A (I assume DIN, equivalent to about 360A SAE). Most modern batteries on the market exceed this comfortably.


1992 VW Scirocco GT II 1.8 90PS Brilliant Black 30k
User avatar
unknownmale
Posts: 991
Joined: Tue Jul 23, 2013 2:34 pm
fill in the right answer: 15
Location: London

Re: Hot start dragging - battery?

Post by unknownmale »

Also worth checking your connections, the earth from the battery to the body and power feed to the starter. see if they're loose, have any corrosion etc.


- David
User avatar
essextom
Posts: 991
Joined: Sat Feb 18, 2012 6:27 pm
fill in the right answer: 10
Location: Chelmsford

Re: Hot start dragging - battery?

Post by essextom »

as above, earths or dicky starter motor.


mark1gls
Posts: 3954
Joined: Thu Apr 02, 2009 9:28 pm
fill in the right answer: 10
Location: Somerset

Re: Hot start dragging - battery?

Post by mark1gls »

Take the earth connections off the battery and give them a good clean up with a wire brush, also follow the earth lead and clean up the other connections.
Another mod is to use a Mk3 Golf earth lead as that has a bit of extra cable which also connects to the engine block at one of the gearbox bolts, you may be able to add just an extra bit of earth cable from the gearbox mount to the engine block...?

Also worth cleaning up the connections on the starter motor.

A lot of places will test your battery to see if it’s any good, cheapo battery’s can last as little as 12 months.

https://www.eurocarparts.com/p/bosch-s4 ... -444770637

£50 with discount.... but get yours tested and connections cleaned before throwing money at the car.. :-D


Mk1 78 Scirocco GLS 1.6 FR, weekend toy.
Mk1 88 Golf GTi cabriolet 1.8 DX. Daily drive.
Membership No. 323
Nate
Posts: 4045
Joined: Thu Apr 02, 2009 10:37 pm
fill in the right answer: 10
Location: Cirencester / Swindon

Re: Hot start dragging - battery?

Post by Nate »

My old mk2 was like this. New main earth cable from battery to engine cured it. Check for this by putting a single jump lead from battery -ve to the block and see if it improves
Last edited by Nate on Thu Jan 09, 2020 9:35 pm, edited 1 time in total.


Image

Check out my photostream on Flickr
'69 bay, '79 bay, '74 bug, '78 GLS, '91 GT2, '10 SAAB 9-3
User avatar
james butler
Posts: 2965
Joined: Fri Apr 24, 2009 1:54 pm
fill in the right answer: 10
Location: birmingham

Re: Hot start dragging - battery?

Post by james butler »

like nate says change the cable first and go from there


I dont mind project cars but I HATE SANDING!!!
Post Reply