29 replies to this topic

[FTodaro]

I have a friend bringing in an NA-18 that intermittently has what he describes as a dead spot when he tries to start the car, It will not crank. Is that a bad starter or is that an ignition switch issue or something else?

 

[Martinracing98]

It can be either. Often if it is the starter, tapping on it will make it start. If tapping makes a difference I would replace the starter. If not I would check tight connections and ignition switch.

[Tom Sager]

If the starter and battery check out OK, you might want to check all the grounds in the battery/kill switch/starter/alternator circuit. 

[Tom Hampton]

What does your friend do to get it to crank, when it won't?

[Steve Scheifler]

As already mentioned, likely the ignition switch, relay, starter, or electrical & ground connections.

In a very quite garage, does it make any sounds at all when not starting, like a soft relay click or louder solenoid clack?

When you smack the starter, do it on the solenoid, that’s typically what sticks. When it won’t crank with repeated attempts (from cold), does the solenoid get warm?

At some point you get the volt meter out and follow the circuits.

[Tom Hampton]

There's no relay in the starting cicuit---the battery is direct wired to the starter. 

1. Unswitched power goes direct from the battery (not through the main relay) to the "B" terminal on the solenoid.
2. Start signal from Ignition switch passes through the clutch interlock switch, then directly to the "S" terminal on the solenoid.
3. Battery return passes through the starter body into the engine block, then back through the engine grounding strap to the chassis ground. Can also pass through transmission case to the PPF to the rear grounding strap (if its still in tact).

 

 

[FTodaro]

Thank you for your input so far, I see the car Tomorrow. This is what it does. puts key in ignition, it clicks turns off key does it again maybe a few times then it starts. Sometimes it just starts, some times its a few attempts of key on and off to get it to start. 

 

So I only know the 99+ cars is the starter relay in main fuse box?

 

Solenoid is on the starter correct?

 

No kill switch in car, its a track car not race car I think.

 

I can give more specifics on noise/sound when i see it. I have a new starter so i will go there after i look over the wiring.

[LarryKing]

When/if nothing happens when turning the key try wiggling the connector on the ignition switch.

[Steve Scheifler]

Solenoid is the smaller cylindrical bump on the starter. When you try to crank, the coil in it is energized and throws the little starter gear out to engage the flywheel/ring-gear, then retracts when you release the key to the run position. The small wire with a spade connector supplies power to it. Pull that off & on a few times to clean the contact, and check that it presses on tightly and that the wire isn’t failing right at the connector. The last couple feet in particular of that wire can get brittle and corroded inside from age & heat; we have replaced a few on early cars.

[Tom Hampton]

Frank -

The starter relay is integrated into the solenoid. As Steve said, the solenoid throws the starter gear out, and retracts it. The solenoid also acts as a contactor between the B and M terminals which energizes the field coil in the motor.

There is no separate starter relay.

If you need an NA fsm, you can download either the NA6 or the NA8 fsm from my website (see sig). The NA6 NA8 starter circuits are identical, so you can use either one. The NA6 fsm has a separate troubleshooting section for the starter. Both have wiring diagrams and system level schematics.

Since the solenoid moves the starter gear, it should be clearly audible when the key is turned, assuming the starter motor doesn't spin.

If you don't hear a click, as Steve said, r&r the S wire to clean the contacts. Also might squeeze the spade connector to ensure firm contact with the terminal.

[Steve Scheifler]

And keep in mind that a starter pulls BIG current so just because you can measure 12+ volts doesn’t mean that the connectors & contacts are not a problem. You may even get a weak clack from the solenoid without it fully engaging.

An old and crude but effective trick is to take the car out of gear, pull off the spade connector at the solenoid, and with an old screwdriver or equivalent bare medal implement briefly short the spade lug to the large positive cable connection near it on the starter. That bypasses all the smaller wiring, key etc to crank the engine. If the key is off it won’t start.

Far better of course is to buy or make a jumper from heavy “primary” wire with a female spade connector or small alligator clip on one end. For a few bucks you can buy one with a pair of clips and a “starter” button between them.

This is all stuff a typical shop will run through in a matter of a few minutes before going deeper.

[RWP80000]

There is also the possibility that the problem may be mechanical in nature.  Not unusual to find an area on the flywheel ring gear teeth that have become damaged to where the starter pinion gear does not ramp into mesh with the flywheel teeth ( commonly referred to as ring gear teeth milling). 

 

A quick test is (with the trans in gear) rock the car so the crankshaft is moved from it's current position and try engaging the starter again.  If it engages and cranks fine it could be a bad spot in the ring gear teeth, starter Pinion gear or even possibly how the starter was tightened into position when last installed.

 

Rich Powers

[callumhay]

Frank
Do you know if the clutch interlock switch is bypassed? If not, you could do that to eliminate the switch. If it was, maybe the method of bypass ( eg a jumper wire) is loose

I like Steve's suggestions on the starter and is a good way to figure out if the problem is in the momentary part of the circuit . Had a similar issue and ran a 12 v line to the small spade connector on the starter and left the line separated inside the car. Turn the ignition all the way on ( 2 clicks) and then briefly touched the wires. car started 100 pct of the time. Problem was contacts in ignition switch

Cal Hay

[FTodaro]

Well i hope the problem is easy, i will send a report back.

[Ron Alan]

Funny how these things come up just when you are having the same issue! Tom's description is spot on(I just had a friend who is a good electrical guy read the 99 schematic for me...his description was identical). My car would start first try sometimes...other times I have turned the key up to 20 times before it engaged the starter. When a no start situation, could never hear anything(solenoid)but the dash lights would dim every time. I swapped the starter...fired right up! Next day...nothing...doh!!! My clutch switch is still in the loop so that is my first thing to by-pass. After that it will be ignition switch!

[Tom Sager]

Well i hope the problem is easy

 

So does your friend who knows what lawyers charge per hour

[FTodaro]

Well the car came in today and i could not duplicate the no start, started up every time. He brought a new starter so i am going to install it. I noticed that the spade  wire that plugs into the starter was oil soaked and not a good connection so i will look that over.

 

If i decide to bypass the clutch switch what is the easiest way to do that as I am old decrepit and don't like hanging up side down.

[callumhay]

In my 1999 there is a white connector on the left side of the footwell. You can see the cables coming from the clutch switch. You can disconnect the connector and cut and splice the wires together and then re insert it ( the connector on the side that goes to the clutch switch) If the car has a roll cage it's a bit of a pain. Not sure if it's exactly the same in a NA 1.8, but splicing the wires is easiest way to go. I pulled the connector from my parts car and then disconnected it in car and re inserted the new one. Other ways to do it, but that worked for me.

Cal Hay

[FTodaro]

In my 1999 there is a white connector on the left side of the footwell. You can see the cables coming from the clutch switch. You can disconnect the connector and cut and splice the wires together and then re insert it ( the connector on the side that goes to the clutch switch) If the car has a roll cage it's a bit of a pain. Not sure if it's exactly the same in a NA 1.8, but splicing the wires is easiest way to go. I pulled the connector from my parts car and then disconnected it in car and re inserted the new one. Other ways to do it, but that worked for me.

Cal Hay

Its basically just connecting  the circuit, is it just two wires? 

[Tom Hampton]

Dunno if this is easiest...but, its pretty easy:

 

 

http://www.tomhampto...ends/#more-2114