intermittent problem - car starter dead, no start

[mlipmd]

Twice now I have gotten stuck with a no start situation. The car has always started instantaneously on turning the key but on 2 occasions after a 15 mile drive and stopping for 15 min., it wouldn't start, wouldn't engage the starter. The battery is good, connections are tight and clean, all lights, radio, AC fan, seats, etc., work, but when you turn the ignition key on, nothing happens, dead, no sound at all. After 20-30 min. it starts like nothing ever happened. I don't know if it's related to the heat under the engine compartment (works when cools off a little?), or to a faulty clutch interlock switch, or to the starter solenoid failing, or to the starter failing. Anyone else ever have this happen or have an idea of cause. It's hard to find the cause when you try it and it works, easier after it fails. Very annoying.

[Andy]

Had the exact same problem on two cars - one a '90, the other a '93. In both cases, it was the solenoid. Since replacement of the starters, I've not been stranded once. I chose to replace rather than rebuild because the cars had 50k-80k miles and their prior maintenance was unknown.

[DRM500RUBYZR-1]

Observe your volt meter when this happens.
If the needle does not move at all then the diagnosis is more detailed.
If the needle deflects when you turn the key from run to start then it is likely your starter, actually the solenoid.
Get it hot, try it, and let us know what you see.

Marty

[tccrab]

An all too common failure in the early ZR1's, easily and permanently fixed.
It's known as the Dreaded No Start.
http://www.zr1.net/forum/showthread.php?t=11727
However, before you decide to perform my mod, you've GOT to rule out all other possibilities.
My mod involves cutting into the wiring harness and bypassing a problem area of the wiring.
Before you do that, do your research.
Rule out everything else before you start cutting wires.
Go to Cliff's Solutions page, start reading.
http://www.zr1.net/forum/showthread.php?t=16778

Then go to Marc Haibec's web site, here's a link:
http://zr1specialist.com/HAT%20Web/a...20problems.htm

If and only IF after you've been through it all and it still won't start reliably, then the DNS mod is what you need.

'Crabs

[Matt B]

+1 one Crabs' post. I had the same issue (but only once) and when the car cooled down everything was good. I added the proposed relay recently as a precaution measure. Cutting wires always hurts - a stranded super sports car hurts even more.
Benefit of the relay is that it adds a "diagnostic port" allowing you to measure current, switch state and resistance conveniently at the relay pigtail in case of issues. And you can direct 12V current (or 24V as sometimes suggested as "boost shot" or "wake-up call") easily to the starter just by using a proper bridge lead. I'm not a fan of mods but this one is worth it.

[Paul Workman]

After owning my Z since 2007, I've experienced both of the more common "no start" situations:

1. The clutch safety switch (primarily on the 90-92 ZR-1s) and
2. eroded starter solenoid contacts.

The safety switch closes when the clutch pedal is pressed, passing current directly to the starter solenoid in the 90-92 MY cars, and to a relay (to handle the current) in the 93-95 MY cars. But, the issue is the current drawn by the starter solenoid is several amperes and the clutch safety switch contacts are eroded by the arching (primarily when the key is turned to start before the clutch pedal switch is closed).

This problem was alleviated in the 93-95 MY cars by placing a relay between the clutch switch and the starter solenoid current. And, by inserting a relay in the path between the clutch safety switch and routing the solenoid current path through the relay, it essentially upgrades the 90-92 cars to the 93-95 circuit design and all but eliminates that particular issue.

Regardless of MY, all of the Denso starters have an internal (solenoid) relay that bridges 100s of amperes of battery current (carried in that "00" copper cable) to the starter windings. Every time the starter solenoid is activated, there is significant arching between the contacts bridging the battery to the starter windings.
Fortunately, overhaul kits for the Denso starter are only around $10 for the contacts, and maybe a piece of emery cloth to polish out the pitting on the bridge ring.

NOTE: There are also kits which include a new solenoid armature/plunger assembly. However, the length of the plunger is critically important that it is neither too long or short or the pinion to ring gear mating is compromised and excessive wear can result!! So, I recommend simply getting the contact kit and shine up the bridge ring with the emery cloth and not compromise the pinion/ring gear mating. And, for what it's worth, my solenoid contacts had to be replaced at 45k miles. (And, I chose to bypass that nanny clutch switch all together!)

Pictured are schematics for the 90-92 clutch circuit upgrade (relay) as well as diagrams from the FSM showing the current flows and values for the 90-92 and the 93-95 clutch circuits. (Note the clutch safety switch is isolated from the direct solenoid current path in the 93-95 MY cars. And, then you can see how the insertion of a relay behind the battery to upgrade the 90-92 cars to reduce/eliminate the arching due to the high starter solenoid current draw (see the STICKY notes for details)

[mlipmd]

If you find the clutch switch underneath the DS dash, can you not just disconnect the wiring plug leading to it and just jump or short out the 2 purple and yellow wires in that connection leading to the switch, eliminating that safety switch? The worst that will happen is that the car will start even if the clutch is not depressed, but everyone who drives a stick shift steps on the clutch and knows this anyway. That seems like an easy way to resolve this issue without tapping into the wiring harness and installing more relays.

[conesare2seconds]

I may have missed what year your car is, but know that something like the purple wire mod has already been done by GM on the later cars. If you have a 93-95 especially, the starter may just be on the way out or the solenoid needs reconditioning. I had all the DNS symptoms on a 94 and Marc found a unique failure mode related to an improper water pump replacement. The starter was ruined by a coolant leak.

[mlipmd]

My car is a '90, #545. The "mod" I am thinking about is just jumping a wire between the purple and yellow in the female connector that goes into the clutch safety switch under the dash, thereby just removing the switch from the circuit. There would be no clutch switch.

[tccrab]

Originally Posted by conesare2seconds

I may have missed what year your car is, but know that something like the purple wire mod has already been done by GM on the later cars. If you have a 93-95 especially, the starter may just be on the way out or the solenoid needs reconditioning. I had all the DNS symptoms on a 94 and Marc found a unique failure mode related to an improper water pump replacement. The starter was ruined by a coolant leak.

Most bizarre!!!
I guess the leak coming from the water pump was being blown under plenum by the air coming from the fan.
Had to have been a pretty big leak for the coolant to make it to the starter before it evaporated.

Was there any exterior evidence of the leak, like drips on the garage floor after the car was parked?



His car is a '90.


'Crabs