Non engaging starter

[jandarah]

Whenever it feels like it, my starter decides not to engage the pinion onto the crown wheel, with just the starter motor whirring away. Then it engages and all is well. As all the moving bits are covered, it is hard to see what is happening in situ. I was thinking that the shaft on which the pinion slides is very dry and needs lubruicating, hence slowing down the full movement. Your ideas, please.

Cheers

[spider2081]

I would have someone help so the solenoid engage voltage (red wire) can be measured at the starter. Any poor connection or intermittent ignition switch contact could cause your problem. Full battery voltage is needed to slam the drive gear forward into the ring gear. Many folks install an relay between the starter solenoid and the ignition switch. It greatly helps having dependable starting.

[DieselSpider]

There is a problem with the drive or the engagement forks not extending properly it could even be that the ears on the forks or the seats are worn and don't always stay in place. You know the starter solenoid is pulling as the contacts to engage the starter motor are not closed until the plunger reaches the end of its travel so since the motor is spinning the contacts and solenoid should be good electrically however the mechanical linkage that engages the drive fork could be worn. Its time to get greasy and pull the starter to either clean and lube the the drive or replace the unit. Usually a replacement drive unit and solenoid costs as much or sometimes more than purchasing a re-manufactured starter with a lifetime warranty.

When you pull the starter most shops such as Advance Auto or Oreilly will bench test it for free.

Drive unit(Lifetime) $26.99:
http://www.oreillyauto.com/site/c/searc ... &make=Fiat

Solenoid (Lifetime) $34.99:
http://www.oreillyauto.com/site/c/detai ... &ppt=C0330

So $61.98 to replace the solenoid and drive yourself without taking care of the bearings, brushes, etc with no warranty on the unit as a whole just on the drive and solenoid plus your costs for cleaner, rags and such that you will use while fixing it.

Remanufactured Starter (Lifetime) $49.99:
http://www.oreillyauto.com/site/c/detai ... &ppt=C0330

[jandarah]

Thank you to both of you,

Firstly, my Spider does have an ignition relay installed and, I also ran some welding cable from the rear battery to the front to overcome any problems with poor earthing in the body from front to back. I don't know when the PO replaced the battery, as it is giving some issues when the car is left idle for a little while. I have a voltmeter installed in in the dash that drops a fair bit when starting. I might get my trusty assistant (wife) to crank the beast while I monitor with a multimeter right at the starter.

OK on the mechanical bits to the starter. My paperwork from the PO says that, apart from the solenoid, the starter motor was overhauled, sometime in the past. So, it looks like I will have to remove it, bench check it and grease it all liberally. I am in Australia, so Spider parts don't come too easily.

Cheers,

[DieselSpider]

Sorry to hear of the lack of parts. Where I live you can walk into just about any shop and they can usually locate a starter and have it in your hands in 24 to 48 hours for about $50 US.

At least the drive on that one is held together with a snap ring and can be disassembled for cleaning and re-greasing.

Hopefully the issue is not stripped splines on the starter motor that engage the inside of the drive.

[baltobernie]

I am in Australia, so Spider parts don't come too easily.

That may be true, but do you have FIAT/Allis agricultural or construction equipment in Oz?

[jandarah]

Yes, we certainly do have Fiat/Allis ag. gear. How does that help with old Spiders?

Anyhow, actually measured the cranking voltage at the starter yesterday ....... 8 to 9 volts! Ouch! Methinks that the purchase of a new high capacity battery tomorrow will change the situation slightly. Poor old starter, doing all that work with so few volts

Cheers

[DieselSpider]

Then with that low voltage there is the chance of some collateral damage to the starter.

It is probably a blessing that it was not engaging and running with the load of actually trying to turn the engine.

[jandarah]

Yes, it will have its full voltage today, after I purchase the new battery. It still did turn the engine, however, it should not have suffered any real damage, only made a sick battery much sicker by demanding a higher current to do the job. For example, a 960 watt (made up here) starter would require 80 amps at 12 volts, but the same starter would require 120 amps to achieve the same result at 8 volts. Not the ideal situation, but, luckily with a starter motor, it only occurs for a short period.

Anyway, all will be rectified today....

Cheeers

[DieselSpider]

Note that you can start cooking a starter in only a matter of seconds and once the voltage gets low the accumulative damage escalates. I lost the starter solenoid on mine over a few months period of while voltage was only slightly lower than spec but not low enough to prevent the car from starting. Yes I have a 2 KW Diesel Starter to deal with instead of a 750 Watt or 1 KW starter more commonly found on a gasoline engine which probably increases the chances for this to occur. The diesel starter is also more painful to replace at $139 to over $200 for a re-manufactured one and you don't want to know what some charge for new ones. My first one went after few months and it blacked out the shop when they keyed it up on the starter tester, unfortunately the warranty was up on that one and it was low voltage to the solenoid that got it. Since the solenoid was not getting enough voltage to clamp the contacts inside properly they carboned up and further reduced voltage to the starter winding's creating hot spots and eventually a short.

I replaced that one with a lifetime unit from the Oreilly Auto Parts chain stores instead of another 90 day unit from a specialty shop along with put in the 40 amp relay to help prevent another low voltage situation at the solenoid. I was checking voltage at the battery lug on the starter which was great with the type 27 - 1,200 CCA battery I have in it however without a helper I was not able to easily check the voltage getting to the solenoid when keying the starter which was where my troubles ultimately came from.

Hope you get by with the new batter however verify and double check the results chasing down any low readings so you can deal with any collateral damage economically before it escalates to another potentially expensive starting issue in the near future.

[spider2081]

Thought this might be interesting read. I believe this is factual.

https://www.physicsforums.com/threads/c ... ns.585336/

[DieselSpider]

Interesting read that does not take into account how a starter is wired internally and the effect that has on draw during the different phases of operation. While the solenoid is pulling initially it goes into a high draw phase to get the starter drive gear extended and then backs off once it is fully engaged however if the battery is weak and it stays part way engaged it will stay in high draw mode and heat up while it then arcs at the contacter. Accumulative damage can set in now that the contacts are carboned up. Theory of operation and the interaction between the fields in the starter and the solenoid is also an interesting read.

[baltobernie]

Yes, we certainly do have Fiat/Allis ag. gear. How does that help with old Spiders?

Then you have industrial electrics shops that rebuild alternators and starters. Your Spider starter uses Marelli components common to their ag. electrics. The outfit that rebuilt my starter in Baltimore was one of these. When I heaved the starter on to the counter, he didn't even blink.

[jandarah]

Thanks for that info. As we are a big agricultural nation on the east coast, there are an abundance of motor rewinders/repairers to all sorts of truck and tractor starters, alternators and electric motors etc.

I fitted the new battery and took it for a big run yesterday. It is nice to see the voltmeter on the dash just drop back a bit when starting the car. Fingers crossed, all should go well now.

Cheers

[jandarah]

Well, starter just loves those 12 volts....