brazilfree

Second time in two weeks. I drove 15 min's got out to eat 30 min came back no start. Lights all came on ... no security light when I turn the key.. so I play around with it (just like last time) for about 40 minutes and it starts like nothing has happened. Idea's and thoughts are welcome. thx :confused:

Mikez40

My 93 ZR-1 did the same thing last week, I stopped for a train crossing. Turned the car off, train passes, go to start the car, nothing, all lights are on but no click or onything. I have to push the car to the side of the road. I wait like about 5-10 min and the car starts like nothing was wrong. I think it is the factory security system, or the chip in my key is going bad. This us to happen on my '86 all the time until I installed the security by-pass switch from Mid-America.

Jeffvette

Typically you've got three possible causes

1. Battery Voltage is low
2. Vats
3. Clutch safety switch

If the car can be push started it's not the Vats, and the security light will go off while you start the car.

Do a search and you'll get some other tips as well

Aaron71771

A problem starting when hot could also be the starter on its last leg, sometime you can jump it and get it to start.

trophystock

I just went thru the same thing on my 90 and have found the problem. When I turn the key I will notice a voltage drop on the gauge (and my meter) as if the car is trying to send power to the starter. An easy way to check this is to turn on the key to the start position then press in the clutch, you should see the volt gauge drop as soon as the clutch safety switch is made (its a good way to also check the safety switch). Well I pulled the upper intake off and put my meter on the starter soleniod wire and had my wife turn the key, well I had power to the soleniod but the starter would not ingage. I found that even though I had almost 13 volts on the batter I had only 11-11.5 on the soleniod wire and that is not enough to engage the starter. I plan on placing a relay under the intake that will use the soleniod wire to activate it and then the relay will send a full 12+ volts to the soleniod. Most relays only need around 8 volts to turn on. I think that this will cure it. I belive the culprit is corroded grounds that cause the voltage drop.

FC2000

Hi!
I have been through everything listed here and more. Bypassed VATS, clutch switch etc....
If it is a hot no start, it is going to be the starter. These cars cook starters with regularity. I ran a wire from the purple wire that goes to the starter and looped into an area I could easily get to. Next time it won't start, I'll hook a volt meter to the wire and confirm that voltage is going to starter solenoid. If there is juice and starter makes no noise, I'll know to replace the starter. :cheers:

trophystock

mine had power to the starter, just not enough to engage it.

FC2000

With low voltage, did the solenoid "click" or was it completely silent?

brazilfree

Thanks, guess I have work to do, one item..if it was a hot start situation with the starter.. wouldn't it happen more... last time it worked for two weeks, or is it normal to come and go regardless. thx again

FC2000

When I had the problem, it was intermitent. That is what made it so hard to track down. Once I replaced the starter I have had no problem. By the way, I bought the starter from "The Last Detail Corvette parts" Great service and good price.

ZR1 MK

I also had this problem 3 times in the last 9 months. All three times the engine was cold and in my garage (not a hot start condition). I have the clutch switch disconnected (bypassed). The security light was ok (vats ok and no codes). I tried all spare keys (all keys currently work). There wasn't a voltage pull. I came back about 40 minutes later and the car started. I am clueless as to the cause. I currently have the plenum off and will put an extra wire as noted by another member.
Mike

trophystock

the soleniod was silent. Mine is very intermitent you can never know when it will run or not.

FC2000

If the solenoid did not even click with 11.5 volts---- it's a bad starter :nopity

trophystock

one would think that but the starter works fine when you take a jumper wire from the starter post to the soleniod post. I toof it off and had it tested and shop said it was fine. It is a new starter though......mayby that's why I got the car so cheap, the original owner was pulling his hair out over stater issuse. :(

ZR1Pete

Somebody here had posted a few weeks ago about a ground wire to a relay under the drivers kickpanel, something about the wire not being big enough or not good ground and they added an extra/better ground to it and fixed there no start problam for good.

The person said Gordon K. told them about this ground problam.
It also mentioned the color of the wire.
If somebody can find this post or if the person can repost the info again that might be the answer to the no start problam.

ZR-the one

Pete:It was one of the wire from the starter relay under the dash I do not recal if it was black or yellow?
Joseph

AspEater

Yes it helps if you have the proper documentation. The
color codes of the wires may not match since this is
from a 90's manual but you at least have an idea how
the circuit works.

If the Pass Key circuit is working which is indicated
by the Security light going out, that eliminates the
contacts in the ignition cylinder that reads the key
pellet. You still need to verify the CCM is grounding
the Starter Enable Relay.

You could have a bad ignition switch which is located
in the middle/top of the steering column. This is
where the 12 volts originates for the starter
solenoid.

When the Starter enable relay is grounded by the CCM,
and the key is in the Start postition, 12 volts from
the Ignition Switch passes through the Starter Enable
Relay, Clutch Safety switch then to the Starter
Solenoid.

So when you have the problem, you need to measure if
you have 12 volts coming out of the Clutch Switch.

If you do, the Starter Solenoid is not getting the
full 12 volts or the Solenoid is bad. Even if the
Starter Motor is bad, you should hear the Solenoid
clicking each time you try the start the car. No noise
means the solenoid is not engaging.

Chevy's have been known to have undersize wiring going
to the solenoids. Over time, the ignition switch
contacts, clutch switch and wiring develop a high
resistance resulting in less than 12 volts getting to
the Starter Solenoid which results in a no start.

The fact that you noticed the lights dim when you try
to start the car would indicate that some voltage is
getting to the starter but not enough to pull in the
starter solenoid.

The Starter has 2 wires going to it. One direct from
the + of the Battery which is used by the Starter
Motor and 1 wire coming from the Clutch Safety switch
and goes to the Starter Solenoid.

The Battery wire is bolted to the starter and the
Solenoid wire is a push on clip type of connector. I
believe they should have used a ring lug with a bolt
but for some reason they used a push on clip.

If you need any more pictures from the manual, I can
e-mail them to you on Monday. 230# LOL. I think
you'll find taking the drivers seat out will make
things easier.
To find the Starter Enable relay.

Drop the carpeted panel above the driver side knee.
It's held on by 2 bolts on the side of the dash and
about 4 bolts around the front.

Disconnect the wire harness to the light and unbolt
the diagnostic connector.

Now remove the 4 10mm bolts holding the metal knee
plate. If you look up by the steering column you'll
see the BACKSIDE of the relays. Two on the left side
of the steering column and two on the right side.

The Starter Enable relay is the 2nd one on the left
side closest to the steering column.

1st (A/C clutch)- 2nd (Starter Enable)-Steering
Column.

This schematic is from a 90's manual so the color
coding may not be the same on your 91. As you can see,
you can unplug the 2 wires going to the clutch pedal
and short the plug out to eliminate the Clutch Safety
Switch.

Some one on the forum mentioned grounding the Black
wire on the Starter Enable Relay. This would enable
the relay all of the time. As you can see in the
schematic, the CCM (central contol module)normally
grounds this wire when the Key Pellet matchs so you
can start the car.


This info is thanks to Jim Robinson, sorry don't remember his Username

My 91 has done some of the same stuff, and it appears to be a high resistance
in wiring/ground problem. I did some cleaning/tightening and haven't had a problem--YET, but I know it will be back cause nothing was replaced.

It always starts cold.
It always starts hot ( 30 min. + operation)
It has failed to start 4 times, always after a cold start and less than 20 to 30 min. operation(like to go get gas,video,milk,some crap I shoudn't do in the first place!) For the most part I almost always get in and go like I ain't comin back(save 4 times!!) so the no start hasn't got me good, like in traffic. I do believe it is in the grounding of the starter enable relay and the load capability
of the wiring from the keyswitch/VATS/clutch safety switch/start enable relay/solenoid. Simply to much crud to get through, to get to the starter.

Don't hear much about 92-95's with this prob., did they fix/mod. some of this system? I know they improved the clutch safety switch, what else?

Good Luck, hope it helps.
TS

MrCrowley

I did a search, and came up with this responce to be the best. Its from A26B!

1. When the car is in it's "no start" condition, connect a test light between the starter terminal "S" (purple wire) & ground (find fuse in underhood fuse block #2 on back of wheelwell, drivers side) & open harness enough to locate wire for probe. Turn key to start & see if voltage. ( I would recommend you locate the lead in the garage @ home when engine is cool & find a place as close to the starter as reasonably possible where you can probe the wire with the test lead that you will keep in the car) IF NO LIGHT, then

2. Backprobe ignition switch connection C1 (red) with the test light from terminal B & ground, (light should come on) then ignition switch C2 (yellow) between terminal A & ground with switch turned to start. (light should come on)

NOTE: Steps 1 & 2 will verify the ignition switch & solenoid wire to the point it was probed in #1. Here's where it gets interesting

3. Remove the starter enable relay & probe from B+ to relay connection #4 purple wire) with ignition switch in start position. (The Starter Enable Relay is located behind the left hand side of the instrument panel, left of the steering column) Light should come on. If not replace ignition switch) If yes, then,

4. Jumper from terminals #1 (yellow) & #4 (purple) (should be directly across from each other on the same end of the relay) of Starter Enable Relay connector, turn key to start.
NO START: open or short in circuit 625 or suspect CCM (central control module)
START : Probably Starter Enable Relay since you have already bypassed the clutch switch.


SHORTCUT: Now, if you are lazy like me, then I might just try a new Starter Enable Relay to see if it works. If not, then about the only remaining possibilities are the ignition switch, the CCM, or an open or short in circuit 625 which is between the Starter Enable Relay & CCM which seems like a long shot to me.

Do you mind telling (1) what the problem was that caused you to replace the starter before all of this, (2) did the problem begin after replacement and (3) where the starter came from, new or rebuilt? No particular reason, just curious.

GOOD LUCK

90 Corvette ZR-1

I think that may have been me. I had the same problem several times. After I bypased the clutch safety switch, I havn't had it since, even after sitting thorught Carlisle traffic. I suggest trying the clutch switch first. Takes very little time and its just a good thing to rule out.

Pull drivers side hush panel. Find Purple wire that goes to clutch
switch. Look at switch and note the color of wire coming back
up.(Yellow??) Will be able to jumper them right there. I used a 3 in
wire with terminals on the end and unplugged the wires going to switch
and plugged in the jumper wire. Use a 12 ga wire at least as it does
carry a heavy current load which is why the switch fails, it gets hot
and the resistance across the points stops current flow.


Hope this helps.

Mylzi

My problem is that car usually starts ok when its hot.. But when engine is cold.. I turn key.. it takes 2-4 seconds before starter comes on.. And its long time keep key turned and wait.. Service thinks my starter is bad..

I dont know whats wrong.. :banghead:


[Modified by Mylzi, 5:02 PM 10/6/2003]