1971 C3 Start/no start-crank condition

[darkstar]

Trying to solve a problem on a 1971 C3 350 CI, HP unknown (probably 270/330, automatic tranny. It will start, run fine then switch it off and try to restart it and nothing but a thunk. (no crank). Wait awhile then try it and it usually starts. Have had the starter replaced as I thought the solenoid was bad ( still do) but the problem persists. HELP PLEASE

 

[Vettehead Mikey]

Hot cranking always puts a strain on the system. Could be weak battery, bad battery cables or connections. Claen all the connections as a no cost first step.

 

[Hib Halverson]

You said you replaced the starter because you thought the solenoid "was bad". You also said you still believe the solenoid is bad.

The new starter you installed...did it include a new solenoid or did you use your old one?

 

[darkstar]

You said you replaced the starter because you thought the solenoid "was bad". You also said you still believe the solenoid is bad.

The new starter you installed...did it include a new solenoid or did you use your old one?

I THINK that the replacement had a new solenoid. I will have to check as I personally did not do it. But I am 99% sure it was both. I have heard the garage is reputable but who knows anymore.

 

[Yoda]

The term "Heat Soak" comes to mind. I had a 67 Corvette that did that on a regular base's. I ended up getting a heat sheild mfr. for the starter and that solved the no start conditions

Here is an older thread that discusses Heat Soak & suggestions for a fix its an older thread, not real long, but with very good information

Bud

 

[darkstar]

The term "Heat Soak" comes to mind. I had a 67 Corvette that did that on a regular base's. I ended up getting a heat sheild mfr. for the starter and that solved the no start conditions

Here is an older thread that discusses Heat Soak & suggestions for a fix its an older thread, not real long, but with very good information

Bud

Some good stuff. I will check out the cables and wiring. And maybe install a high torque starter if necessary. I remember the Heat Soak problems I had in my 66 Nova. 327/365. Time made me forget all about it. Thanks!!

 

[GTR1999]

My 69 was like that. I'd drive it in the summer when it was hot out and then go to start sometimes and it was dead to the world,just like the battery was disconnected. Waited a while and it turned right over.

What I did was to tear down the starter and rebuild it. Then added the GM spring and heat wrap. I checked the wire harness as well and found the ends were spliced with some undersize wire and loose connections. I repaired the ends using the correct wire gauge and it seemed to solve the problem.

 

[72VETTE454]

I installed one of these remote solenoids on mine after being fed up with hot soak restart problems. Never had a problem since. And my starter did/does have the production heat shield. Good luck.

 

[darkstar]

Thanks to all . Found out had some broken starter bolts, wiring harness problems and some other problems. I am still assisting in returning the "Vette" to a steady running state. (also had a weak solenoid spring). Will keep you posted.

 

[Yoda]

darkstar,

It is ALWAYS nice when someone posts back with an update and with good news. Your experience and sharing back your results WILL help someone else down the road

THANKs

Bud

 

[82CorvetteCE]

Since you have things apart, be sure to inspect the solenoid inner copper contacts as well as the starter brushes.

Had the same thing happen to me and it turned out to be (2)worn starter brushes with nothing wrong with the starter.
Starts every time even when hot; no problems & no heat shield.

 

[darkstar]

Thanks to all.

Well we got it running . There were some mechanical problems with the engine. Replaced the starter with a high-torque one , redid the wiring. somewhat and the positive battery cable. It looked fine but had a slight bulge in it. When I cut it open- all corrosion. It will be a 330+HP 350ci all said and done.

 

[wallyknoch]

Replaced the starter with a high-torque one , redid the wiring. somewhat and the positive battery cable. It looked fine but had a slight bulge in it. When I cut it open- all corrosion.

That was your problem, the corrosion on the battery cable..it was seeking ground and the next thing you should check is the shifting cable for the same corrosion as it may break at a ill opportune time...

 

[darkstar]

That was your problem, the corrosion on the battery cable..it was seeking ground and the next thing you should check is the shifting cable for the same corrosion as it may break at a ill opportune time...

I am sorry, but you lost me on the shifting cable. Please enlighten this old geezer. Brain dump.

 

[c3cvte]

agreed. Most people check hoses and belts as part of a routine maint. but neglect to check other vital parts. Shifter linkage/cables can leave you stranded. or atleast stuck in 1 gear. tach cables can lock up and strip out your distributor. speedometer cables, and on and on.

Had the tach cable issue. That sucked. well not really. told my wife I had to replace it with the MSD 6AL system. she bought it

 

[darkstar]

agreed. Most people check hoses and belts as part of a routine maint. but neglect to check other vital parts. Shifter linkage/cables can leave you stranded. or atleast stuck in 1 gear. tach cables can lock up and strip out your distributor. speedometer cables, and on and on.

Had the tach cable issue. That sucked. well not really. told my wife I had to replace it with the MSD 6AL system. she bought it

I get it now. Shift cable in a corvette just threw me. Linkage I get it. And I agree with you fully on the rest of preventive maintenance. Some things like the speedometer cable or tach gear/cable ,I best think you leave alone until a symptom arises?? Just me. Thanks for the input.

 

[TimAT]

Electricity will seek the easiest path to ground. I've seen shifter cables welded solid by starter current. Bad ground between the engine and the frame, so the shift cable took the load. Grease cooked and it welded the cable and housing together.

Ground path was from the starter, into the block, to the trans, out thru the selector shaft to the shift cable, up to the shifter and fried the cable.

 

[darkstar]

Electricity will seek the easiest path to ground. I've seen shifter cables welded solid by starter current. Bad ground between the engine and the frame, so the shift cable took the load. Grease cooked and it welded the cable and housing together.

Ground path was from the starter, into the block, to the trans, out thru the selector shaft to the shift cable, up to the shifter and fried the cable.

I am lost again. Transmissions have metal shift linkage not cables that I can recollect. Help !

 

[TimAT]

Automatics with floor shift have a cable- looks like a park brake cable. And if you still have the pre 77 cars with the "lock in park" there's another cable there.

1968-1976 Corvette Auto Transmission Shifter Control Cable | Zip Corvette Parts

 

[wallyknoch]

I am sorry, but you lost me on the shifting cable. Please enlighten this old geezer. Brain dump.

Its not only Vettes, but all automatics that utilize a shift cable....noticeable whenever a car produces symptom of hard starting or slow cranking...The starter most always gets the blame in this situations and probably 75% of the time it was not the starter...We sold one of the best starters in the Nation. However selling the best don't always satisfy a customer when they can buy the 'lifetime' down the street...Depends on whose life its measured by...In Detroit its not very long...Anyway broken shifter cables with a white corrosion on the broken ends show that the engine is seeking ground wherever it can find it. These can be anything including emergency cables, shifter, and even brake lines. This happens when the primary grounds are corroded and over time the get thin and break from carrying the starter load...and its not the battery either but the ground that needs the attention...This so called 'heat soak is a incorrect diagnosis as everything gets hot and every time too, They didn`t crank hard when new...clean the grounds and especially the one right under the battery attached to the cross member...no one does however