Author Topic: Starting problems  (Read 34799 times)

mikefam

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Starting problems
« on: June 05, 2015, 08:13:48 PM »
I've been troubleshooting a starting problem for a month now and several times I have thought that I've found the problem because I make a correction and the car starts fine. Then a few hours or a few days later it goes dead again. I've corrected a bunch of flaky connections and replaced the horn relay, ignition switch and neutral safety switch.

My question - what should the voltage be at the starter solenoid with the key in the start position? I am getting a large load when I turn the key and the voltage at the solenoid purple wire is about 8vdc. The solenoid is new.

TIA, Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Starting problems
« Reply #1 on: June 05, 2015, 08:33:43 PM »
After posting my original question I went to teh car and connected a jumper cable from the negative battery to the exhaust manifold to test the ground to the engine. The car started. I thought taht I had found a problem until I removed the jumper cable and the car still starts. So now it is acting like heat soak but I'm not ready to accept that based on the fact that it has run good for the past week when hot and that it has also died for days where nothing I did helped. I'm stuck.

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Starting problems
« Reply #2 on: June 05, 2015, 10:25:22 PM »
Also has anyone changed the under-hood wiring harness on a first gen with the engine installed. The car is fully assembled and it would be good to hear from someone who has done it.  The biggest problem I foresee is the heater blower motor wire which is under the passenger fender. Are there other pitfalls that you know of?

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

BULLITT65

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Re: Starting problems
« Reply #3 on: June 06, 2015, 03:27:56 PM »
Well I saw nobody had responded to you yet, so I thought I would give it a whirl.

Maybe you can help me out with some more details.

I am guessing this is the 68 Camaro with a 327 you reference in your signature?

Do you run headers on the motor by chance?

When it doesn't start have you tried taking a screw driver and taping the solenoid to see if it is stuck? ( I understand it is new)
1969 garnet red Z/28 46k mile unrestored X77
-Looking for 3192477 (front) spiral shocks 3192851 (rear)
-Looking for an original LOF soft ray windshield
-Looking for original Delco side post negative battery cable part # 6297651AV

mls68z28

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Re: Starting problems
« Reply #4 on: June 06, 2015, 04:21:57 PM »
how about the starter.
Mitch,1968 Z28 03C Norwood,03/18/68,Seneca Falls NY,Z/28 Emblems.Purchase 05/04/78

janobyte

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Re: Starting problems
« Reply #5 on: June 06, 2015, 04:25:33 PM »
bad grounds will create many a ghost to chase in the electrical system. Clean battery to chassis , coat with some dielectric grease. Check body to chassis ground straps (cooper ones off the fire wall) When I say check ,I'm talking removing-cleaning contact areas-grease. Make sure starter is grounded.    Theses are freebie fixes--square that away, and move on to other areas if need be.

When you say dead ,engine not turning over ? Or not firing?



Well Bullitt, you know how it sometimes is here...
68 Z/28  born with: 302, drive line, etc..

janobyte

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Re: Starting problems
« Reply #6 on: June 06, 2015, 04:37:41 PM »
bad grounds will create many a ghost to chase in the electrical system. Clean battery to chassis , coat with some dielectric grease. Check body to chassis ground straps (cooper ones off the fire wall) When I say check ,I'm talking removing-cleaning contact areas-grease. Make sure starter is grounded.    Theses are freebie fixes--square that away, and move on to other areas if need be.

When you say dead ,engine not turning over ? Or not firing?



Well Bullitt, you know how it sometimes is here...
bad grounds will create many a ghost to chase in the electrical system. Clean battery to chassis , coat with some dielectric grease. Check body to chassis ground straps (cooper ones off the fire wall) When I say check ,I'm talking removing-cleaning contact areas-grease. Make sure starter is grounded.    Theses are freebie fixes--square that away, and move on to other areas if need be.

When you say dead ,engine not turning over ? Or not firing?



Well Bullitt, you know how it sometimes is here...


Yea! I was sort of assuming he changed it as a unit ,but if not, who knows what shape the brushes/armature's in ? Engine harness shouldn't be a pain to change. Front lighting harness warrants removing driver's fender. ( not a big deal, get another set of hands, keep shims together and mark on the tape/bag their location)

68 Z/28  born with: 302, drive line, etc..

BULLITT65

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Re: Starting problems
« Reply #7 on: June 06, 2015, 04:38:43 PM »
well I know this is not as exciting a topic as a survivor article, so not as many guys jumping on this topic. I saw he posted 3 times without a response, so I thought, I may not be the know it all but lets get some discussion going to find the solution. Hopefully we can help pin point his issue. :)
1969 garnet red Z/28 46k mile unrestored X77
-Looking for 3192477 (front) spiral shocks 3192851 (rear)
-Looking for an original LOF soft ray windshield
-Looking for original Delco side post negative battery cable part # 6297651AV

janobyte

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Re: Starting problems
« Reply #8 on: June 06, 2015, 04:41:22 PM »
Also check for corrosion where the harnesses plug into the firewall, they were known to collect moisture, hence causing issues.
68 Z/28  born with: 302, drive line, etc..

janobyte

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Re: Starting problems
« Reply #9 on: June 06, 2015, 04:42:16 PM »
 ;D
68 Z/28  born with: 302, drive line, etc..

mikefam

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Re: Starting problems
« Reply #10 on: June 06, 2015, 04:44:07 PM »
I've been through the starting system from end to end checking for voltage drop and have made a bunch of improvements. Each time I made an improvement the car would start for a while and then fail again. Sometimes in hours and sometimes in days.

I have replaced the following

14 gauge fusible link on +battery
horn relay
removed and cleaned connections in bulkhead connector
new accel ignition switch
new accel neutral safety switch
removed fuse box and scraped spade connectors clean
replaced the section of the purple solenoid wire that runs behind the engine (it was brittle)
installed ground wire from -batt to fender brace
new solenoid switch

When it fails the starter works fine if I cross the purple wire with +batt at the starter motor. When it fails I find that I only have about 8vdc at the neutral safety switch as opposed to 10vdc when the car is starting properly. There is a voltage drop that I haven't been able to find. I'm working alone which makes it difficult because I have no one to turn the key when I need them.

This morning I removed and cleaned the buldhead connector for the second time. It is working fine right now so I am waiting for it to fail again to do more testing.

Mike.



68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Starting problems
« Reply #11 on: June 06, 2015, 04:46:18 PM »
I should have explained that the solenoid does not click. The voltage drops to 8vdc but the solenoid does not switch. It seems like an intermittent connection somewhere along the line.

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

BULLITT65

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Re: Starting problems
« Reply #12 on: June 06, 2015, 04:47:11 PM »
Do you have headers?

When it doesn't start have you tried tapping on the solenoid to see if it will fire?
1969 garnet red Z/28 46k mile unrestored X77
-Looking for 3192477 (front) spiral shocks 3192851 (rear)
-Looking for an original LOF soft ray windshield
-Looking for original Delco side post negative battery cable part # 6297651AV

mikefam

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Re: Starting problems
« Reply #13 on: June 06, 2015, 05:04:31 PM »
No I haven't tried hitting the solenoid because i am working alone. But it is the second solenoid in a year. I replaced it along with the starter about a year ago and then again recently when the car dies altogether. It has had an intermittent starting problem for a few years.

68 Convertible w/327 275hp donor engine from a 67 Impala and TH350

mikefam

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Re: Starting problems
« Reply #14 on: June 06, 2015, 05:06:38 PM »
bad grounds will create many a ghost to chase in the electrical system. Clean battery to chassis , coat with some dielectric grease. Check body to chassis ground straps (cooper ones off the fire wall) When I say check ,I'm talking removing-cleaning contact areas-grease. Make sure starter is grounded.    Theses are freebie fixes--square that away, and move on to other areas if need be.

When you say dead ,engine not turning over ? Or not firing?



Well Bullitt, you know how it sometimes is here...
bad grounds will create many a ghost to chase in the electrical system. Clean battery to chassis , coat with some dielectric grease. Check body to chassis ground straps (cooper ones off the fire wall) When I say check ,I'm talking removing-cleaning contact areas-grease. Make sure starter is grounded.    Theses are freebie fixes--square that away, and move on to other areas if need be.

When you say dead ,engine not turning over ? Or not firing?



Well Bullitt, you know how it sometimes is here...


Yea! I was sort of assuming he changed it as a unit ,but if not, who knows what shape the brushes/armature's in ? Engine harness shouldn't be a pain to change. Front lighting harness warrants removing driver's fender. ( not a big deal, get another set of hands, keep shims together and mark on the tape/bag their location)



Yes it is behaving as if it can be a ground that comes and goes. The last time it failed I put a jumper cable from the neg batt to the exhaust manifold and it started. I thought that I was on to something but then when I removed the jumper cable it still worked. I am chasing ghosts.

Mike.
68 Convertible w/327 275hp donor engine from a 67 Impala and TH350