drd21968

thaught i had this problem fixed,replaced starter and still had problem,replaced relay and no problem for several months.tonight it does it again,in the past after it was push started it would start,this time when i got it home it still wont start.i really hope it wont start and i can once and for all find this problem.if anyone knows of somthing i missed let me know

SPEEDEMON

Try the ignition switch.

Vette Guy

When you turn the key, do you hear the fuel pump turn on? The first question to answer is if it is VATS related. I've been through this problem in-depth.

Best Regards,

Mark

Blown67427

More than likely a low voltage going to the starter issue.
A problem with 90 thru early 92 Z's.

Locate the big purple wire in the harness located under the ecm. Check the voltage, if it's under 10.5 you're going to have to install a relay, and get the power directly from the batt.

Tyler Townsley

Jumper around the clutch switch. You can do this under the dash. Find the purple wire going to the switch and coming back from same and jumper it. The switch is too small to handle the current going through it. This was re-engineered in later models.

Tyler

drd21968

would i be rigt in assuming it is not in the vats or the ignition if it will push start thanks

-=Jeff=-

This was a problem with my 90 and my 89 L98 car ( with 91 dash).

I fixed the 90 with the relay. 89 will get fixed when I bring it home from storage..

Blown67427

It rules out the vats. Like I said, if you check the volts on the big purple wire and it has less than 10.5 volts, you will have found the issue. Make sure to test the big purple wire, as there are several smaller purple wires in that harness. If you have a test light,with a sharp point, just ***** the wire.

ZR WON

How old is the battery? If it has any age on it whatsoever, I'd replace it. The starter is *very* sensitive to voltage and if the battery is even a bit weak, it will show the symptoms you describe. I've known several Z owners who have gone through the same procedure you outlined, only to change the battery as a last resort and have it solve the problem.

Brian A.
90 ZR-1
12.09@118
01 Z06
not quite stock

terryszr1

like tyler said ck the clutch switch. turn the key to start , watch the volts gauge on the dash . now push the clutch in and out does the voltage on the gauge change ? if not its the clutch switch

drd21968

car started right up today,would not start even after push starting when i got it home.it seems to not want to start if it sits for around 1 hr.it makes no sense to me ,when i have had the no start it under those conditions

dallas916

If all else fails, and if you have any kind of aftermarket remote door lock/unlock/security prompt system..yank it out and use only the original factory system. It will cost around $250-300 to have it professionally removed by a dealer, but it stops the conflict between any of those systems and the GM system.

WydGlydJim

If I ever have this issue, I will bypass the switch first, because it is a mod that needs done anyway. Then, I will work from there.

drd21968

if the votage is weak coming thru switch will it not also have trouble engaging relay?if im thinking right on installing this relay,cut purple wire,connect wire from firewall to coil on relay,connect a ground to other side of coil.run a hot from battery to common on relay,then the purple to selenoid to normally open contacts,but if voltage is being lowered thru clutch switch wont this problem still exist.are there no upgraded clutch switches i can replace mine with thanks

-=Jeff=-

No the Coil voltage and current for the relay will be much less then that of the solenoid.

typical min voltage on a relay will be 8v, anything less then that is will not energize.

My 89 L98 does the SAME thing and I have a brand new starter in it. I will add in the relay to make it work all the time

Tyler Townsley

In the early cars all the current went through the clutch switch rather than using it to pull up a relay that was designed to handle a higher current load. This tends to overheat the switch which has a much lower current rating, this causes the no start. One could rewire this to make the switch a pullup for a relay which is how the later cars were designed.

Tyler

Vette Guy

I know all these posts are sending you in many directions... Need to nail down if this is VATS or not. Doesn't seem like you have if you could not even push start it. I've been through the entire process twice in my first 2 years of ownership. First time was a loose starter relay... bad contacts. Second no-start situation was a starter going bad. Would only start by directly jumping the purple wire to the battery. I rebuilt the starter with parts from a LT1 or L-98 starter and it has worked like a champ for the last 4 or so years.

The first question is if you hear the fuel pump energize when you turn the key. If so, not a VATS issue and you should be able to push start it. If not, then we are looking for a VATS demon.

Mark

drd21968

not vats it will push start every time

-=Jeff=-

That is EXACTLY what I did, I just need to connect in the clutch switch, Previous owner bypassed it by removign the harness side connector..

At least when I was troubleshooting my 89 I made a heave gauge jumper and left the connector in place

40ZR1

When you push start, after engine is running is the yellow 'Security' light on in instrument console? If it is you have an ignition switch problem.
Gordon Kilebrew sells diagnostic plugs that plug into console under driver-side. Great for trouble-shooting! Good Luck!!