Starter or something else?

[Funracer]

Sounds like the starter is the culprit,*

How so? If it works on the charger should'nt it also work from the battery if the battery is OK?

Anyway I will get after it in a week or two. I work for UPS so not much free time from now till New Years.

Happy Turkey Day to all tomorrow!

[Bearly Flying]

If the solenoid pull's in, that means the safety circuits have been satisfied.
The only reason the starter does not crank, is worn solenoid contacts.

You can bypass this that or the other thing, But it all comes back to worn or eroded contact points.

Pull the starter and replace the solenoid contact faces. Problem solved........

[Funracer]

Home for a couple of days and got out the DVM. With battery tender attached and DVM touching the battery posts reads 12.7 v. Disconnected tender and started engine on first try. DVM on the battery posts now reads 14.7 v at idle. Went for a 3 mile drive got back to my garage turned off the engine. Tried to start it again no start only heavy click under the hood. Checked battery voltage again still showing 12.7v.

My conclusions are battery is good, alternator is good. Not sure what to think about the starter bc it always works when its been on the tender or jumper cables hooked up for 20-30 mins. I dont mind changing starter if I'm sure thats where the fault lies but it would suck to change it and it behaves the same as it does now.

Next time I'm home will try to test the voltage regulator. Any other suggestions appreciated.
Thanks

[Dynomite]

Here are some suggestions for ya

If you decide to fix the Starter issues once and for all....remember to check the two small bearings on each end of the Starter Armature. Just spin them and check for roughness. Those two small bearings are easy to pull and replace with new bearings.

Four things I ALWAYS do on any LT5.

1. Pull Plenum and BLOCK TB Coolant.
Eliminated IH Housing and Throttle Body (TB) Coolant system Tricks
Removing Plenum (including the 10 minute Plenum Removal)

2. Check for Vacuum leaks and recondition/clean the area under the Plenum including the Valley Drain.
Finding A Vacuum Leak

3. Pull Starter and recondition Starter Solenoid and Starter.
Starter Rebuild

The Starter Solenoid is shown in the left photo with slight burnt contacts in right photo.


The Solenoid contacts in left photo were wire brushed clean in right photo.
Also use a bit of emery cloth on the two fixed contacts.


If you want to go further with the starter rebuild, check the two bearings on each end of the Armature for roughness.

Photo provided by mgbrv8 Complete starter rebuild by mgbrv8 (Dave)



Check the two bearings on each end of the Armature for roughness by spinning with your fingers. If any roughness, replace with new bearings (pulling the bearings with a small bearing puller).

4. Install Starter Relay.
Starter, Starter Relay, Wiring Harness, Battery, and Plugs Tricks
Electrical Ground Connections and Installing Starter Relay

Just have to say this one more time.

These ZR-1s are over 20 years old and many have not had the Injectors replaced, Starter Reconditioned, or even the Plenum removed.
Time for some Maintenance. And it only takes three days......one day to remove Plenum and clean up area under Plenum, One day to relax and think when engine is drying out from HOT Pressure Wash, One day to put it all back together with new Plenum Gasket (and some other stuff) from Jerry .

Minimum Restoration of a 1990 ZR-1

You will see in this Minimum Restoration that TB coolant appears intact but actually is blocked from both directions (see item #18.6).

Six things I ALWAYS do on any LT5.

[Paul Workman]

Just following along here....

It appears the batter/alternator have been eliminated, AND the loud "click" under the plenum suggests perhaps the circuit(s) involved at least up to the starter solenoid are OK (for now), which leads us to the starter solenoid itself (likely) or even the starter itself (remote chance, but can't be ruled out yet).

FWIW, the starter solenoid contacts in my 90 crapped out at around 45k miles. And, so it seems many other too have serviced their solenoids approx the same time.

Anywayz...some facts is always a good place to start:

% Marc Haibeck, this schematic and voltage readings may come in handy at some point...

C this link...

http://s185.photobucket.com/user/6PP...ml?sort=3&o=15

But, back to your situation, barring the clutch safety switch being bad, like I said, the focus now is on the starter solenoid. (You'll need some plenum gaskets from Jerry's Gaskets on hand, just in case.) I'd recommend pulling the starter, and inspecting the solenoid's high-current connections. Replacing the copper "L" pieces is practically a "given" (so cheap that any time I have to pull the plenum, I R&R those contacts as a matter of routine).

There are kits on ebay to refurbish the solenoid, but be especially careful the plunger pin part of the assembly is the right length. One I got was shorter than the stock one, which would have resulted in only about 50% of the starter pinion gear being engaged on the ring gear. (So, I simply cleaned up the stock copper contact ring and so far it has worked for 6 years and 18k miles w/o fail.)

Also, you will note too that the battery connection to the starter is underneath, between the starter and the block. It too can get corroded, and the rubber boot gets brittle too. Might want to service that connection as needed, while you're in there.

BTW, now might be a good time to R&R the ignition coils and inspect the secondary circuit to see the tubes are not cracked and rubber connectors are in good shape.

Well, good luck on the starting issue. I'm NEVER a fan of "replacing parts untils the problem goes away", especially as a means of trouble shooting. It's always better to know how the system works, and then never assume(!) take measurements, and focus on ONE issue at a time until completion.

Anyway... I'd bet a ham sandwich the problem is the starter solenoid, at this point. Do let us know what you find, tho.

Paul.

[Funracer]

Thanks for the detailed and well written suggestions.
Paul you said "barring the clutch safety switch being bad" etc. With bad clutch safety
switch there would be no solenoid click, right? Power would never get that far or am I wrong?
I said earlier that car started when extra voltage supplied by the charger. From DVM reading I see that the chargers brings the battery to 12.7v and keeps it there not higher like i had assumed. Engine starts easily. After a drive DVM still reads 12.7v at the battery but no start. That is whats throwing me. Heat affecting the solenoid?
On a side note had the plenum off for a couple of months last summer while plenum was powder coated. At that time I removed and cleaned the starter wires which were pretty clean to start with. Coils also only have a few hundred miles on them. Secondary system has been removed. No codes thrown.
Ham sandwhich? It probably is solenoid but trying to eliminate other possibilities before third plenum pull this year.

[RICHARD TILL]

My car is doing the same exact thing. Its starter time for me. Right now its sitting in the drive during a heavy rain storm. Waiting on 3-4 folks to come by and help me push it uphill in the shop. It`ll be my 4th plenum pull this year. 1. Tried to repair secondaries. 2. Bad coil. Replaced with MSD`s. 3. Tied secondaries open and bought a chip. WOW! 4. 12 year old starter that i hope i can rebuild.

[Bearly Flying]

If you are getting a loud click when you hit the Key, that tells you the VAT's, and the Clutch Safety Switch have already been satisfied.

The problem is the Starter Solenoid contacts.




Notice the depleted edge of the contact.






Corrsion/Errosion of the Contact face.






Looking down into the solenoid case. Note the wear pattern.



I bought replacement contacts from the local Chysler Dealer, The Cummins Diesel uses a Nippon Denso Starter, and have a larger contact face than our ZR-1's do. The cost was $3.00 for the contacts, I just cleaned up the face of the armature contact.

[Paul Workman]

Originally Posted by Bearly Flying

If you are getting a loud click when you hit the Key, that tells you the VAT's, and the Clutch Safety Switch have already been satisfied.

The problem is the Starter Solenoid contacts.




Notice the depleted edge of the contact.






Corrsion/Errosion of the Contact face.






Looking down into the solenoid case. Note the wear pattern.



I bought replacement contacts from the local Chysler Dealer, The Cummins Diesel uses a Nippon Denso Starter, and have a larger contact face than our ZR-1's do. The cost was $3.00 for the contacts, I just cleaned up the face of the armature contact.

Bohy gawd...I tink he's got it!!

Yep, that's zackly what happens in roughly 40k miles or so, and it (the starter) needs periodic servicing i.e., new contacts and (bridging) ring.

I got the rebuild kit off ebay, but later discovered AutoZone had them, so no doubt others do too: a common repair item, apparently.

BUT! a word of caution: IF the kit includes a new plunger/ring assembly, be dang sure the thrust pin (that pushes the pinion gear to align with the ring gear) is the same length. Not all are correct. (The one in my kit was NOT the right length, so I had to clean up the pocking, etc left as result of arcing. A bit of elbow grease and some fine emery paper...good as new!)

[Funracer]

3rd plenum pull of the past 12 months scheduled for next week. Not one of those wimpy half pulls where you undo some of the stuff around the edges and rest the front edge on a 2x4. I'm talking about unhooking everything top sides front back and underneath and putting the plenum over on the workbench while you commence an LT5 rehab of some sort.