Bus fails to start. Starter motor or something else?

True!

Fortunately the rain and hail from the coastline made fire impossible. But it did give me an impression of what being submarine mechanic must be like.

 

If you read the wiring diagrams carefully on e.g. theSamba.com you will see numbers on the wires. Which are the cross sectional area in mm2.


So the Black starter connection wire is 25mm2


[It also shows how you could crank test the starter by connecting pin50 on the test socket to pin+ on the test socket.]

 

Hi everyone. I just wanted to do a round-up now I have the time. I have used this forum for a lot of work, and I know a breakdown of the issue can be handy!


Problem: When turning the key in the ignition, the bus either did not turn over - or if it did try to turn over, it appeared to be struggling. Finally, the bus refused to crank over at all. The issue got worse over a few days and escalated from being only intermittent to frequently refusing to start.

The starting problems seemed utterly random at first. It did not matter if the engine was hot or cold. I.e., if I had been driving for hours or starting the bus up for the first time that day. Finally, the bus completely failed to start one evening, and I posted here for help!


This is the process I followed to get the bus to work with each part labelled, there are some pics below, as well as useful links and a list of equipment and specifications. Lastly, there is the contact info for help if you are ever stuck in Newquay!

Distributor: I have a Tune123+ distributor. This is an electronic distributor that is programmable via Bluetooth. It has an 'immobiliser' function, which can be turned on using an app. It seemed the unit was no longer connecting to my phone, so I did wonder if the dizzy was failing/immobilised. I also checked the distributor cap, HT leads and coil connections to ensure they were ok.


Battery: I tested the battery, and the voltage before starting was 12.4 volts and rose to 13.4 volts once the engine was running. All of the wiring had been replaced on the bus recently (apart from one wire!!!)


Engine: I turned the engine by hand using the rear pulleys and with a socket, which thankfully told me it was not seized.


Starter: Checking the bus was not in gear, and the handbrake was applied along with some wheel chocks. I turned the ignition on and got under the bus. I then bridged the terminals across the back of the starter with a screwdriver - lots of sparks! But, no cranking of the starter, and also, there was no noise from the solenoid.

This led me to believe the solenoid was not engaging and may have been stuck....


Solenoid: I whacked it with a hammer! Then I tried bridging the terminals on the starter to see if I had loosened it. Still, nothing happened.


Bump start: There was a hill at the hotel which I was at the top of. I tried bump starting the bus down the hill, but it did not work.
Jumpstart: Again, did not seem to work.


Everything seemed to point at the starter/solenoid being the issue! After posting to this forum and talking to some local garages, I decided to fit a new starter. I sourced the new starter from EuroCar parts in Truro (I was in Newquay) and had a taxi pick it up for me! (Not the cheapest option)

I fitted the new starter and.... now we had a crackling noise. This was correctly diagnosed as a low battery issue - I had been trying to start the bus for a while without the engine running.

I charged up the battery and the starter worked! Except, instead of starting the engine, it just made a whirring noise like an electric drill... The starter was too short and was spinning freely (not engaging the engine....) I knew from the engine install from earlier this year that the bell housing was not the correct depth for a 3 rib gearbox (see pics below). Double check the length of your starter and bell housing before installing! It is worth noting that the new starter came with a bushing which I could see my engine was missing entirely. This is an often overlooked part that needs to be replaced when installing a new starter. Be warned. The old bushings do not come out easily!


Starter wire: The only wire I did not replace during the restoration... It turns out it was not in a good state at all. There was a lot of electrical tape hiding the issues and coupled with the dark and grime under the bus, and it was hard to see just how bad it really was (see pics below). I pulled the wire out and crimped a new one. Luckily I had a length of 25mm2 black wire and terminals with me as spares!

Lastly, I checked the old starter and found that it would not spin by hand and was stuck fast. I started to whack it on the floor in desperation as hard as possible, and that finally did the trick!! I would not have been able to apply that much force from under the bus with a hammer.

I refitted the old starter back to the bus along with the new starter wire and full battery, and it came to life!!! We made it back home the next day. I will replace the starter along with the gearbox in the near future as it is. The battery is also not holding charge anymore, which likely contributed to the issue.


All in all, it was a bit of everything that was the problem. I hope my (mis)adventures help someone logically work out their issues in the future. Apologies for the essay, but it may help someone. Thanks again to everyone for their help!!


Starter motor comparison, older (and longer) starter is on top.



Close up of the two. Again, the old/longer starter is on top:


Corroded starter wire that was hidden under electrical tape. Note, the terminal fell off in my hand after this picture was taken:


Youtube links:
Bell housing size guide:
How to replace a starter motor:
Starter motor bush replacement:

Local help:
- VW RICH 07977 597633 vw-rich.business.site. Note, only does water cooled but was incredibly helpful and helped me get in touch with local air cooled experts:
- West Coast VW 07762 422330 westcoastvw.co.uk
- Eurocarparts Truro, GSF car parts, Car Vogue limited - all had parts in stock and near(ish) to Newquay.

Equipment list:
Battery: S5 010 Bosch Car Battery 12V 85Ah Type 110 S5010. Fitted in August (5 months ago).
Charging system: DCC50S 12V 50A DC-DC On-Board Battery Charger with MPPT. (Acts as a VSR and solar charge controller)
Engine: 1600 - bored out and stroked to become a 2 litre. Twin carbs etc.
Distributor: Electrical distributor, Tune 123+ Bluetooth system

 

Great write up and pleased you are back on the road again

 

Wow! I bet that old starter took the brunt of your frustration with that hammer! Great determination and resilience Jay! Well done mate. One question. Changing your gear box seems drastic. Can’t you get a new starter that fits the current bell housing? Ie the longer starter.

 

Thank you mate! And, thank you again for your help.
The starter certainly got hit hard mate that’s for sure!

Yes, you are correct that would be a drastic solution to the problem. But, with the new monstrous engine installed, the 3-rib gearbox is simply geared too short now. For example, 1st gear is entirely unusable. However, it is still a great gearbox! And, if I had the stock 1600 on, I would not be changing it at all.

I was mainly waiting for the bank account to recover from the engine, wiring and leisure electronics (+ this fun starter motor jolly!) that have all been done this year! Wife said something about food on the table for the kids or something?

 

Ah! Ha ha. I get it now….completely!