Starter motor problems...

[cooky73]

Hi all,

I have replaced the starter motor on my 1970 bus, removing the old bush and knocking in a new one but the engine still turns over very slowly and will not start!

Tried a good battery, tried the starter off the van and it turns but only what seems slowly, but I have never seen another starter of this type so it may be the right speed!

Any ideas?

Neil.

 

[Moseley]

Check and clean all wiring and connection points. Most likely cause will be lack of current getting to the starter because of a damaged cable and not a clean connection being made to the chassis at the ends.

 

[cooky73]

Starter seems OK now, tested it properly and it whizzes at high speed.

Have taken out the plugs and tried to turn the engine using a spanner - it won't move - how easy should it be to turn over?

 

[Moseley]

Starter seems OK now, tested it properly and it whizzes at high speed.

Have taken out the plugs and tried to turn the engine using a spanner - it won't move - how easy should it be to turn over?

Hmm, something is amiss there - I can turn mine over with the plugs in. I'd have thought without the plugs you should be able to turn it without a spanner even.

 

[cooky73]

Have removed the starter too so it can't be that....

Any ideas anyone?

 

[Moseley]

It is in neutral?

 

[cooky73]

Yes, it is in neutral and rolls easily.

 

[RePhil]

You won't be able to run the starter on the bench without supporting the pinion end (to do the job of the bellhousing bush when in situ).

The starters on these engines are similar to most other pre-engaged starters. i.e. They should sound & spin the engine just like any other engine.
A tired battery or, as has been mentioned, bad connections will cause the starter to turn slowly. Battery, starter & engine /gearbox earth connections.

However it does sound as if the engine may be stiff somehow.

This could be anything inside the engine, as if it's about to seize. You should be able to turn it with a spanner on the bottom pulley quite easily.

Why did you change the starter in the first place?
Also what is the history of the engine? Was it running OK or has it always been like this?
Has it just been rebuilt by any chance, as a lack of lube during assembly or overtight (incorrect) bearings might do this.
If it is seized solid you need to get it out & have a look. Look at the clutch area first though before stripping the engine down.

I hope this helps. And let us know - we love a mistery, as long as it's not disastrous!

Phil.

 

[cooky73]

Engine is a newly built and has done 50 miles, it's under warranty so can't touch it just yet...

Changed the starter as I assumed the engine was OK!

 

[RePhil]

It does seem to be mechanical if it's stiff to turn over with a spanner.

PS mystery

 

[Moseley]

Have you spoken with the company who supplied / built the engine? Are they local to you so that they could see it for themselves?

 

[cooky73]

Have tried to contact them so just waiting for a reply now...

 

[cooky73]

Have managed to turn it using a wrench but it is still very stiff.

Starter turns it very slowly too. Could it be the live feed to the starter? Bad earth maybe?

Don't want to try a bump start in case it damages the engine...

 

[privatejobs]

the engine is seized partially

 

[Moseley]

What did the engine builder say? Have they offered to take a look?

 

[cooky73]

I have had the guy who supplied the engine to look at it and he still thinks it is starter related.

Gonna try some new earth straps for the battery and gearbox.

Volts at the starter drops to almost nothing when you try to start it, dunno if that is right or not...

 

[Peter Good]

Sadly not correct. The voltage at the battery and / or the starter motor (terminal 30) should hold at around 10 volts when cranking the engine. Most starters are tested when new to function to about 8.5 volts, depending on the manufacturer. If you are getting almost zero volts then I suggest you replace all three of the battery cables; positive battery to starter, negative battery to chassis and the most likely cause of the problem, the chassis to gearbox. Total parts cost around £30 - £35 job done!
Peter Good

 

[cooky73]

Ok fitted new earth lead for the battery and one for the gearbox too.

I checked the 12v from the ignition with someone turning the key and that was fine 12v.

I also checked the volt drop across terminal 30 and the earth and it drops to about 7.5v when it is trying to start.

The engine will not turn manually even using a breaker bar at the flywheel.

My engine builder has suggested the end float has tightened in the running in period...

 

[privatejobs]

oh shit :shock:

 

[Peter Good]

A voltage is 7.5 volts is a typical stall voltage when the load on the starter is excessive. You can tell your engine builder on my authority that the problem is not starter motor related. (even if was possibly earlier)
Sadly for all concerned, he has got a real problem to sort out for you!
Peter Good