Shimming the Starter

[garageguy]

Hi Guys

'74 124 Spider...originally 1800cc. Have had it for about a month...steady progressing on a mild resto.

Since I have had the car, I am having a starter system issue. Most of the time it starts on first key turn. On those off times where it doesn't start or crank, I hear a clunk like the solenoid/relay are working but no starter turns. Sometimes it can take 5+ attempts to get er going. Sometimes, depressing the clutch helps...also, cranking is generally slower than other cars I have had.

So, is there a weak spot in these starter systems? Since I am hearing a clunk, it sounds like the solenoid is engaging but only part way, do you think shimming the starter could help?

Thanks all

Damon

[kilrwail]

I'd start (no pun intended) by checking the battery first. Shimming the starter is the beginning of an ugly trip down a slippery slope of work-around fixes, usually attributable to the previous owner. Give the battery a good charge or substitute a known good one and see if it doesn't help.

[DieselSpider]

Yes first ensure you have good power to the starter and the starter solenoid. The solenoids push and hold the starter drive into the gear on the flywheel and can draw 10 amps or more which is a pretty big load directly on the contacts inside the ignition switch. One of the best things you can do for your ignition switch is put a relay between it and the starter so there will only be a few Milli-amps load while starting on the ignition switch and you can have a nice heavy wire and relay feeding the starter solenoid for a more secure starter drive engagement.

Many have experienced what your describing as the click of death that comes just before an ignition switch fails completely from the load the solenoid puts on it.

[wetminkey]

Your starter needs better electrical contacts, and a starter relay is the proper way to get that, just as DieselSpider stated.
I just bought a series of three relays from Auto Ricambi. The Fiat Spider should have several relays that it does not,...and the three will only remove all of the start/run loads from the ignition switch,...

[SteinOnkel]

I've got this same issue with a new(ish) Lada switch and a brand new starter. All wiring is gucci.

I'll add a relay to it, thanks guys.

[18Fiatsandcounting]

Good suggestions above about the battery, connections, and adding a relay, and I'll add one more possibility. The solenoid actually has 2 functions, one to push the starter motor gear onto the flywheel ring gear, and at the same time to make the direct electrical connection between the + side of the battery to the starter motor.

I have seen quite a few starter solenoids where the internal (copper) contacts were so corroded or fouled with dirt and oil that, while the solenoid would engage the flywheel, the connections inside the solenoid weren't good enough for the 200+ amps or so needed to turn the starter motor. The result was the starter motor turned slowly, or not at all. In the latter case, all you got was a click from the solenoid when you turned the ignition key.

The solution is a new solenoid, or for the adventuresome, take apart the solenoid and clean the large copper contacts inside.

-Bryan

[DieselSpider]

Good suggestions above about the battery, connections, and adding a relay, and I'll add one more possibility. The solenoid actually has 2 functions, one to push the starter motor gear onto the flywheel ring gear, and at the same time to make the direct electrical connection between the + side of the battery to the starter motor.

I have seen quite a few starter solenoids where the internal (copper) contacts were so corroded or fouled with dirt and oil that, while the solenoid would engage the flywheel, the connections inside the solenoid weren't good enough for the 200+ amps or so needed to turn the starter motor. The result was the starter motor turned slowly, or not at all. In the latter case, all you got was a click from the solenoid when you turned the ignition key.

The solution is a new solenoid, or for the adventuresome, take apart the solenoid and clean the large copper contacts inside.

-Bryan

Yes indeed! And many times the starter motor contacts inside the solenoid get damaged due to the weak starter switch not making good contact so there is not enough current to fully deploy the solenoid and firmly close the contacts so that arcing occurs burning out the solenoids contacts prematurely. When weak contact is made by the starter switch the solenoid can bounce a few times under load doing a lot of damage to its contacts.