Intermittent issue starting the car , VATS or starter problem? ---

[alwayscode390]

I have had an intermittent problem with my 90' ZR-1 starting.

It has happened 3 times now, two times at the mechanics but ended up starting after sitting for about 15 minutes there.

It just happened right now and I couldnt get it to start even after sitting for 30 min.

I drove the car earlier today without issue.

Does it sound like a VATS issue or my starter dying?

When I go to start it , NOTHING ... no clicking or anything, the dash just lights up.

When I have the door open the SECURITY light flashes , but I am pretty sure it has always done that.

Thanks! ---

[LGAFF]

Most likely the clutch safety switch......can bypass it, pretty easy to do....but have to be careful when starting.

Although as a bonus, if you are ever stranded and need to move the car up a driveway could probably run it off the starter motor

[LGAFF]

http://www.zr1.net/forum/showthread....Starting+issue

[XfireZ51]

Yep, that clutch safety switch is just a bitch to get to.

[alwayscode390]

So the clutch safety switch is depressed with the pedal , like the brake switch right?

I just swapped out the brake switch to get my 3rd brake light working again, about 2 months ago.

I actually just went outside and stood on the pedal with more force than normal. I could have sworn to hear a slight "click" from the pedal ... then it fired right up!

I may have tried starting it too quickly , the link Lee shared above stated that you should never try to start and push the clutch at the same time ... I will be more mindful of this from now on.

Thanks! ---

[max76]

Alwayscode390,I have the same problem, but i have already bypass vats system and clutch pedal...i also have new starter contact....
2 week ago i put a switch with the positive from battery and the purple wire (to the solenoid)....in the same time i put a new ground wire from the negative of the battery to the frame.
After all these modify i run all the sunday, with a lot of starting without any problem...
i hope it was a bad ground connection!!!!

[max76]

Alwayscode390,I have the same problem, but i have already bypass vats system and clutch pedal...i also have new starter contact....
2 week ago i put a switch with the positive from battery and the purple wire (to the solenoid)....in the same time i put a new ground wire from the negative of the battery to the frame.
After all these modify i run all the sunday, with a lot of starting without any problem...
i hope it was a bad ground connection!!!!

[alwayscode390]

WOW, I used to own a 1991 Syclone Truck and they talked about the "purple wire mod" to the solenoid.

Is that an issue with our ignition/starter system too since they are both GM and of the same age?

I hope you fixed it Max! Thanks for the suggestions ---

[max76]

Alwayscode...your name is Nathan????
I'm Massimiliano on facebook, from Italy!!!

I don't know if is the same issue of the syclone...i also take note that the abs service light now is off. I must reset the ecm, but i used the car for about 10 miles and the light was always off.
This is a good sign...i hope the new ground is a good job for our little issue!!!!It's a fast job to do...

[Paul Workman]

Originally Posted by alwayscode390

So the clutch safety switch is depressed with the pedal , like the brake switch right?

No. Just the opposite.

Originally Posted by alwayscode390

I may have tried starting it too quickly , the link Lee shared above stated that you should never try to start and push the clutch at the same time ... I will be more mindful of this from now on.

Thanks! ---

The clutch (interlock) safety switch operates like the door (courtesy light) switch. When pressure (on the plunger) is released (as the clutch peddle is pressed) the switch closes and completes the circuit to the starter (on the 90-92s).



For 93 thru 95s the relatively high current is re-routed so that the start current by-passes the clutch pedal switch, significantly reducing clutch switch failing significantly...

Note: The (above) diagrams courtesy of Mark Haibeck's article from Heart Of The Beast).

Just this past week, I too experienced that clutch safety switch failing. This was in spite of being mindful to depress the clutch pedal completely before turning the ignition switch. The problem was foretold by the starting becoming "sketchy" (intermittent). For verification, I temporarily bypassed the switch, and now there is ZERO hesitation or erratic starting as I noted up to the time the switch finally did fail completely.

Here is a bypass circuit I designed to alleviate the load on the clutch switch for the 90-92 MY cars; moving the load to a more accessible, plug-in relay.



Of course simply by-passing (eliminating) the clutch safety switch eliminates the problem, and this aux. relay (above) would not be needed; so why bother?

Pros and Cons of keeping the switch:

Pro:

Safety. The car will not start unless the clutch is depressed.

Con:

1) The car can be started without having to climb into the drivers seat and depress the clutch. This is convenient in many situations.
2) It is possible to move the car a (very) short distance by rolling the starter alone should the engine be dead (for example).

fWIW,

Paul.