Starting issue

[JMO343]

Hey guys - just drove my car home. Turned it off in thr drive way and now it will not start battery is good. Is there something with the the security system / key thst will not ket the xar start ?? Any help wouldbe great.

John

[Dynomite]

Does the starter Solenoid move (is there a click and reduction in voltage by diming lights for example)?

If so.....that no start issue will be intermittent until you recondition the Starter Solenoid points. In Emergencies the Z is very easy to push start by hand in second gear pop clutch with key on.

[JMO343]

No starter clicking and lights are all bright.

John

[jmglyder]

Hello,

This has happened to me several times when I first got my ZR1. I realized that each time it happened it was because I was not fully engaging the clutch which prevented it from starting. Part of the security system.

[JMO343]

Clutch is down to the floor

John

[Ccmano]

When you get in is the security light on the left side of the cluster blinking?
H
:cheers:

[JMO343]

Yes it is.

John

[onetinsoldier]

Try splicing into the large purple wire in the harness in the back near the firewall . Then touch it to the positive on the battery , see if that spins it over . Make sure its not in gear !

[Ccmano]

Yes it is.

John

When your inside and the door is closed does it go off?
H
:cheers:

[Ccmano]

In addition, once in the car, door closed, turn the ignition on without attempting to start, does the security light go out after 2 seconds?
H
:cheers:

[-=Jeff=-]

Car was warm or cold? I’d warm you need the start rebuilt or replaced

[Top Toy]

Did you try jump starting it? A friend with a'91 had the same problem. Two year old battery that appeared "good" was the culprit. Replaced the battery. Starts every time now.

Sent from my HTC U11 using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[JMO343]

Thanks guys for the help. My car started up after it sat for a while. Not really sure way?

John

[geezer]

60 / 80 AMP RELAY SPDT SINGLE POLE DOUBLE THROW

Check this item out in Dynomites 'Solutions' at the top of Tech .forums!! Electical Ground Connections And 'Installing Starter Relay'. From experience this will solve your Issue!!!!!

Installed under ECM and in slot between brake booster and fire wall (perfect place for location of Relay).

Wiring modified a bit to assure Pin #87a is not hot at any time.
Pin #30: Purple wire to starter (use 3/8 inch connector on relay).
Pin #87: Red wire battery positive 12v use 3/8 inch connector on relay
(Same gauge wire as purple wire connected to battery positive multiple connection post).
Pin #86: Battery ground (1/4 inch connector on relay connected to ground where battery 12 gauge wire grounded).
Pin #85: Purple wire from clutch switch in wire bundle under ECM use 1/4 inch connector on relay (Red wire on early 1990 ZR-1).
Pin #87a: Not hot at any time and not used.


Insert a short 1/2 inch long section of plastic hose
over the center connector on the Relay which is NOT
used in this application.

[-=Jeff=-]

Thanks guys for the help. My car started up after it sat for a while. Not really sure way?

John

starter solenoid contacts need to be replaced

[JMO343]

Is this something that happens when the is hot?

[JMO343]

Car is hot?

[-=Jeff=-]

Yes, that is what I had to do to my car. I have also done the mod Geezer listed. But still had the hot start issue. Start solenoid contacts fixed the issue

[JMO343]

Ok thanks. Regular parts store or dealer?

[Dynomite]

starter solenoid contacts need to be replaced

Or Reconditioned...…...See

Post 52 - Starter, Starter Relay, Wiring Harness, Battery, and Plugs Tricks (https://www.corvetteforum.com/forums/c4-zr-1-discussion/3005470-tech-info-lt5-modifications-rebuild-tricks-500-hp-3.html#post1581564085)

https://cimg1.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x300-1/80-bac49725_6086_4f07_a929_9f1f498e4d50_1__dab0355503 a648614325bf258970d05c5b00e0f3.jpghttps://cimg2.ibsrv.net/gimg/www.corvetteforum.com-vbulletin/350x300-1/80-e8886408_e5b8_40d3_a5d2_199e22f85e0a_1__8099e51dcf e7e3aac179a153f6cd3d0edc6d6515.jpg

[BigJohn]

Check Battery Cables?

[shawn8492]

Mine did this and I bypassed the vats system. I went to breakfast and came out and ir woupdnt start. Everything else worked. Has not done it since the vats bypass so I hope that was the problem.

Sent from my SM-G930V using ZR-1 Net Registry mobile app (http://r.tapatalk.com/byo?rid=90383)

[JMO343]

I just took my out to vacuum. It ran for about 10 mins in the the driveway. Go back to try and start it. No luck. Starter solinoid???

John

[JMO343]

Sorry car.!!

[GOLDCYLON]

60 / 80 AMP RELAY SPDT SINGLE POLE DOUBLE THROW

Check this item out in Dynomites 'Solutions' at the top of Tech .forums!! Electical Ground Connections And 'Installing Starter Relay'. From experience this will solve your Issue!!!!!

Installed under ECM and in slot between brake booster and fire wall (perfect place for location of Relay).

Wiring modified a bit to assure Pin #87a is not hot at any time.
Pin #30: Purple wire to starter (use 3/8 inch connector on relay).
Pin #87: Red wire battery positive 12v use 3/8 inch connector on relay
(Same gauge wire as purple wire connected to battery positive multiple connection post).
Pin #86: Battery ground (1/4 inch connector on relay connected to ground where battery 12 gauge wire grounded).
Pin #85: Purple wire from clutch switch in wire bundle under ECM use 1/4 inch connector on relay (Red wire on early 1990 ZR-1).
Pin #87a: Not hot at any time and not used.


Insert a short 1/2 inch long section of plastic hose
over the center connector on the Relay which is NOT
used in this application.


Normally this is the solution. My 91 was done by the previous owner because he was stuck several times. Once the car cooled down it will start again. This solves that problem.

[Paul Workman]

Woah! My I say that ALL of the suggestions so far are all valid - far as they go. But, what is lacking is a methodical, logical progression to isolate the problem so that it can be dealt with properly.

Good troubleshooting begins with: KNOWING HOW THE SYSTEM WORKS

If this were my issue (and it has been a couple times over the last 11 years) I'd want to have a roadmap and be able to go step by step. And, maybe the best way to do that is to have a schematic. HOWEVER, it would help to know WHAT YEAR ZR-1 we're dealing with here; a 90-92 or a 93-95 MY?

OVERVIEW:

Before the battery is connected to the starter windings, FIRST there are 3 SWITCHES that must be satisfied (turned ON).

In the case of the 90-92 cars, the starter current first passes through a STARTER ENABLE RELAY (controlled by the CENTRAL CONTROL MODULE [think VATS]), then second through the CLUTCH START SWITCH, and then to the starter solenoid. Within the solenoid housing is a third HEAVY CURRENT switch, activated by the first two switches. This last switch HIGH CURRENT switch connects the battery directly to the starter windings and supplies the HIGH CURRENT power needed to spin the motor.

The "Achilles heal" is the CLUTCH SAFETY SWITCH in the 90-92 cars carries the relatively high current drawn by the starter's solenoid. This high current load results in arching between the contact points within the switch*. The points are eroded by the heat generated by the arching until they begin to fail intermittently at first, but failures increase until the failure becomes total.

NOTE: One can reduce the arching in the CLUTCH SAFETY SWITCH significantly by FIRST pushing the clutch peddle to the floor BEFORE turning the ignition switch to START.

The 93-95 MY cars starter circuits differ slightly in order to eliminate issues stemming from the high current in the 90-92 CLUTCH SAFETY SWITCH.

Instead, the CLUTCH SAFETY SWITCH current is routed to a separate ENABLE relay controlled by the CENTRAL CONTROL [VATS] MODULE). Because the current through this (beefed up) ENABLE relay is very much lower than that in the 90-92 cars, the issue with arching is greatly diminished and thus the "NO START" dilemma is significantly reduced!

Modification for the 90-92 MY Zs

*By installing a auxiliary relay (modification - see "Solutions" sticky) - the current through the CLUTCH SAFETY RELAY can be significantly reduced and start reliability greatly increased.

ALL THAT SAID, none of the (above) means squat to the starter. How the current gets to the starter solenoid switch doesn't change the erosive effect arching will have on those contacts! Sooner or later, the contacts will need to be serviced.

The MEAN TIME BETWEEN FAILUREs for the contacts is measured in the number of switching cycles, NOT mileage. (In my case, the contacts had to be replaced at about 37-40k miles.

Your mileage may vary! But, it is prudent to inspect and R&R whenever taking delivery of an older car, and like changing all the fluids, inspecting/replacing the starter solenoid contacts should be on the list!

The schematic on the left is for the 90-92 MY and the one on the right is for the 93-95 MY ZR-1s.

.

[JMO343]

I will check the security light. If I have to change the starter does anyone know of good Corvette shop close to Long Island that can do this work?


John

[zrfast1]

Just my .02 but I had the same issues you have and drove me nuts. My starter was rebuilt, so I know it wasn't it. Clutch bypass wasn't bypassed so I did it. No joy. Long story short....cleaned the battery cable connections...never had an issue again!!

[JMO343]

I have not done the starter yet and battery is new. How hard is it to replace the starter?


John

[zrfast1]

Starter is located under the coil packs which are under the plenum in the valley of the engine. Take a wire brush to the cable of the connection to the battery first and make sure the cables are very snug, wiggle the cables while tightening..do not over torque! Also do the clutch bypass.....its very easy before you tear into the plenum. Just my .02

[DRM500RUBYZR-1]

There have been a number of suggested things to check that you have not responded with the results.
While it may very well be your starter, why not humor us and go through the basics first.
You replaced the battery.
Why, when and with what?
How do you know that it is good?
How did you test it?
What are the results?
Cables.
Clean? no fair to not remove and look!
Tight?
After checking for clean make sure that they are tight.
Twist them to make sure they really are tight.
Are the wires tight on the connection beneath the battery?
Don't touch them with the battery connected.
Are they clean?
What is the security light doing when you get in it, and when turning the key?
Have you tried another key?
Often, owners mistakenly think that it is a hot-start issue, when in reality the VATS has activated the start prevention sequence delay.
Did you remove all floor mats and push clutch fully to floor? Are you sure?


Once all of that is out of the way, please describe what the voltage gauge does as you turn the ignition from on to start when the no start occurs.


Depending on your answer it will lead to one of only two or three things.
Let us know where you are with these steps.
Thanks,
Marty

[JMO343]

Thanks for your response. I have only had the car for two weeks and it is not on the road yet. The owner I brought the car from just replaced the battery a month ago. As I said the car starts find when it is cold. I drove the car home and it was about a 25 minute drive. Shut it off in the driveway and it would not start. Waited an hour and it started right up. Same thing happen when I had it running in the driveway for 15 minutes. Would not start until it cooled down. The security light is blinking until I put the key in and then goes out and clutch switch I believe is working because the car starts up cold. I have not checked the battery cables yet. Not sure how this will affect the starting when it is hot?? I hope it is not the starter. I only have one key for the car at this time.

[DRM500RUBYZR-1]

OK.
"please describe what the voltage gauge does as you turn the ignition from on to start when the no start occurs."
Look carefully.
Thanks,
Marty

[JMO343]

Ok I will check it out and let you know. How does the battery cables play into this? What happens to them when the car gets hot?

[DRM500RUBYZR-1]

Ok I will check it out and let you know. How does the battery cables play into this? What happens to them when the car gets hot?
As parts degrade, and combined with the additional load of heat, oftentimes, a battery or circuit that works acceptably when there is less demand, fails when confronting the higher demand.
I have replaced many "new" batteries, that were not quite new, and when tested failed to deliver the required voltage.
Same can be said for cables and connections.
I just don't want to see you pull the plenum unless and until you are very certain that it is indeed the starter that is failing, particularly if you will be paying a shop to do it for you.
While it likely is the starter, absent confirmation you have the proper voltage getting to it, I would be reluctant to just replace it without checking the simple and inexpensive things first.
Again, I have replaced many batteries that just could not deliver the proper voltage and cranking amps needed.
Thanks,
Marty

[JMO343]

I hear you!! May be the battery the old owner replaced it with does not have enough cracking amps when it gets hot. What should the cracking amps for a ZR1 battery?


John

[DRM500RUBYZR-1]

I hear you!! May be the battery the old owner replaced it with does not have enough cracking amps when it gets hot. What should the cracking amps for a ZR1 battery?


John



John,
I believe they call for 690.
The battery should be delivering 12.8 volts minimum at all times.
When it is less on C-4's ( and newer) odd things happen.
Clicking noises from relays going on and off, "SYS" appearing in the information display, and if the starter has the usual failing i.e. worn/corroded internals, insufficient power to energize the solenoid, at first when hot, then even when cold.


We often get hot starter failures to start by jumping with a running car.
The added oomph on occasion can rescue a stranded owner.
I don't like to do it, as it is a great way to overpower the CCM and ECM, causing failure.
So I always start with a battery test, then the cables, then a quick look at the major starting circuit connections to make sure we are delivering all of that power to the starter.
If all of the power is there, then either the vats or the neutral safety/ clutch switch and circuit is the next suspect.
Once you have ruled all of that out, then you might as well order the plenum gaskets, and the starter parts.
You will get it resolved!
Marty

[JMO343]

Just ran the car for a while shut it down and it will not start. Battery light comes on and gauge is only showing about 10 volts when I turn the key to start. I am thinking I have battery problem and not a starter problem.

John

[Ccmano]

Just ran the car for a while shut it down and it will not start. Battery light comes on and gauge is only showing about 10 volts when I turn the key to start. I am thinking I have battery problem and not a starter problem.

John

If not already done, put a VOM directly on the battery to get a reading. Don’t trust the dash gages. If it’s truly 10 volts you may have a battery issue. A battery capacity test is the best indicator.
H
:cheers:

[conesare2seconds]

Mine does the same. Drops to 12v but will start with a jump. The voltmeter doesn’t dip when you turn the key and the security light doesn’t flash. Pretty sure it’s the clutch switch. I’ll look into it further when the weather cools off a little. Let us know what you find out with yours.

[lfalzarano]

Battery?


Lou

[conesare2seconds]

Good suggestion, but mine got a new one. Thank you though.

[JFFerner]

You may want to try charging your relatively new battery for several hours via battery charger to be sure there is sufficient cranking capacity at the amperage you need with a hot engine.

[DRM500RUBYZR-1]

You are shooting in the dark until the battery has been tested with professional equipment.


Brand new batteries can lose a cell if they lose a charge.
They may "act" normal under light load after being charged, but reveal their faults when the slightest of demands are put on them.
A real piece of test equipment is not just a meter, but rather also replicates a load and observes and reports the findings.


Remove the battery and take it to a parts store or shop that has the proper equipment.


Step 1 is the battery.


Marty

[Paul Workman]

I have not done the starter yet and battery is new. How hard is it to replace the starter?


John

Changing parts in lieu of testing/assessing their performance FIRST, and (worse) THEN assuming b/c it was replaced it therefore couldn't be bad = TWO CARDINAL SINS when it comes to troubleshooting.

1) That method = VERY expensive and not at all an effective way to "troubleshoot".

2) Because the two most vulnerable times for a new part to fail is WHEN IT IS FIRST INSTALLED (and put into service), and after the part has achieved it life expectancy. But, of the two periods, the chance of early failure is by far the most likely time for a part to fail - statistically referred to as the "infant mortality period".

Now, if you determine the CLUTCH SAFETY SWITCH is not the issue (i.e., you've actually MEASURED the voltage on the purple wire going to the starter and you have at least (say) 12 volts on that wire (when the clutch is depressed and the ignition switch is in the START mode), then the next most likely (as Cliff and others have said) is the starter's solenoid switch.

An overhaul contacts kit for the Denso starter can be had for under $10, and can easily be replaced by anyone that can handle very basic tools and take less than 10 minutes (tops) to replace them, once the starter in in hand.

A WARNING tho.... Some Denso overhaul kits also include a replacement solenoid armature (consisting of a copper ring on one end, the armature body, and a plunger pin on the other end. It's than plunger pin that can be an issue - IF IT IS NOT THE SAME LENGTH AS THE STOCK pin! That being the case, you can shine up the contact area of the copper ring and reuse the stock armature. Installing an armature with a short plunger pin results in the pin not pushing the bendix gear into the ring gear (on the flywheel) and both the bendix gear and the ring gear will suffer excessive wear and premature failure.

Far as pulling the plenum and the coil pack to access the starter, it is a "RITE OF PASSAGE" for a new ZR-1 owner to accomplish! Most of the "goodies" reside under that plenum, and that is a good place to do some preventative maintenance "while you're in there". Just drain about a gallon of the coolant from the radiator (drain spigot is on the lower corner of the radiator on the passenger side, facing toward the motor). Then remove the hoses and electrical connections (being ESPECIALLY CAREFUL of that big DIS connector at the back of the plenum so as not to bend or break any of the many pins).

The coil packs are easily accessible and the mounting plate comes off easily. Then the starter is easily removed and the solenoid is accessible for service. (My solenoid contacts went just over 40k miles before needing attention. But, in each case the mileage depends on how the car was driven to that point. "Your mileage may vary!" (as they say).

Point is, you can save yourself hundreds of $$$ by pulling the starter and servicing it yourself (if that is even determined to be necessary). And, chances are that unless the shop is in fact familiar with the LT5, they won't know where to access a new plenum gasket. They then will either attempt to repair the torn gasket (often resulting in a vacuum leak later), or ask you where to acquire one (Jerry's Gaskets).

I vote that you pull the plenum yourself. You'll gain a substantial amount of general knowledge as far as how the secondary port throttle system works AND the overall condition of the lines and rubber connections, actuators and mechanical condition, inspect the plug wires - replacing them maybe and the possibly the coils too, and inspect the drain tube under the back of the starter to be sure it is clear of gunk. And, what better time to do some house cleaning!

Gotta run! Good luck!

[Ccmano]

You are shooting in the dark until the battery has been tested with professional equipment.


Brand new batteries can lose a cell if they lose a charge.
They may "act" normal under light load after being charged, but reveal their faults when the slightest of demands are put on them.
A real piece of test equipment is not just a meter, but rather also replicates a load and observes and reports the findings.


Remove the battery and take it to a parts store or shop that has the proper equipment.


Step 1 is the battery.


Marty

Agreed, take the battery to an Autozone store and have them do a battery capacity test. It’s the only sure way to know.
H
:cheers:

[JMO343]

Looks like my starting issues are behind me now. Battery was no good under a load. Replaced it with the correct Delco battery and cleaned all the connection. Took the car out for nice ride came back and shut it down in the garage. Waited a minute and it started right up. Hopefully this was my issue.

Thanks everyone for you input and help.

John

[zrfast1]

You will someday go under the plenum. The battery was an easy fix. Good job!

[Ccmano]

Looks like my starting issues are behind me now. Battery was no good under a load. Replaced it with the correct Delco battery and cleaned all the connection. Took the car out for nice ride came back and shut it down in the garage. Waited a minute and it started right up. Hopefully this was my issue.

Thanks everyone for you input and help.

John

Congrats, as I said, a battery capacity (load) test is the only reliable way to know if the battery is good. More often then not it’s the simple things. Now go and enjoy the car while the weather holds up.
H
:cheers: