[tsmith455]

I have a 71 TA 455HO auto car. It starts when its cold, however fails to start when it gets hot.....sometimes......pretty consistently. The engine harness has been replaced with an M and H harness from Ames when I restored the car, I have replaced the solenoid twice and the starter once, also replaced both the Negative cable and positive cables. I have adjusted the neutral safety switch, checked the shifter switch and adjusted the switch on the steering column. The ignition switch feels like it could have some wear, as it doesn't move a smoothly as it should, however has never failed to power the car.....it just won't engage the starter when this happens. The car has tilt and I have checked the switch in multiple positions and power at all levels. I have been fighting this ....intermittently for over a year and have finally run out of ideas. I recently replaced the solenoid again and thought I had things fixed, started every time for about a week and then one day, stopped for gas, got in to start the car and nothing. Exactly the same issue. When this happens, I have lights, I can turn the key and volts register on the gauge, however NOTHING at the starter. Can't hear the solenoid click at the starter.....absolutely nothing......let the car sit for about 45 minutes and usually the car starts right up......although....not always.

The last time this happened, I jacked the car up and jumped the solenoid Battery wire to the ignition side of the solenoid with the key on and the car starts right up.

The car is stock, except for the Pertronics ignition.

Completely perplexed and out of ideas at this point. Any help would be appreciated.

Thank you,

Tom

[starlightblack]

GM hot-start is a pretty common ages-old problem. Usually, insulating the solenoid from underhood exhaust heat is the answer - a heat shield around the starter or fabric wrap on the starter does the trick in my experience.

[T A 70]

Even without headers it may be time to throw a mini on that bad boy.
I just love them and super reliable on all my cars.

[SD73]

If you have the opportunity next time it happens, I'd throw a meter on the connections at the starter to see what type of voltage you're getting at the end point. Then you'll know definitely your starter is getting power or not. After that I'd work my way back and maybe you will get lucky and find it's that ignition switch or possibly a loose connection or bad ground somewhere along the way. The point is to try to get some info when it happens. If you're on the road when it happens try turning your lights on when you start it and have someone check to see if the lights dim when you hit start and that should tell you if your starter is getting some juice too.

[SD73]

re-reading what you've already tried, it does sound more like an issue prior to the starter and not the starter itself. That old harness under the steering column and ignition switch is sounding more suspect. At least check the harness to the switch for breaks. Also I'd check the terminals all your harnesses are plugged into for corrosion.

[70RAlll]

Smith455-

I have been through this problem more than most and can give you a $2 solution. The GM starter, what ever the model was of this design...can't recall the numbers, something like A5, damn thing weighs every bit of 20 lbs and was used for many years across all lines??, anyway, was notorious for going bad and having the hard start problem. Mechanics would just replace the entire unit originally(which is why our original '8436's are so rare), but soon realized just replacing the solenoid would fix it, which is why you always hear, as you already have on this thread, it is most likely the solenoid. It is and it is not the solenoid. The solenoid consists of the actual cylindrical solenoid and a large spring inside, approx. 2" in diameter and 3" long. THAT is the problem. If that spring doesn't hold enough tension, it will not engage the starters teeth with the flywheel. After many cool down and extreme heat up cycles, the spring looses its spring. All Solenoid kits come with a new spring, which is why replacing the solenoid almost always solves your problem. It wasn't the new solenoid, it was the new spring that came with the solenoid that fixed the problem. SO.. take your starter off, take the solenoid off and pull out the spring. Go to NAPA and tell them what you have and they will have to pull out one of their books(this is not a stupid computer look up item) and get a new $2 spring.. When you set them on a table side by side, the new one is almost a full inch taller. I have a box of old solenoid springs here from repairing to conserve the original solenoid with my original '8436 starters(I have 5 now)..

And you have not seen me on this board much, but there are enough guys here who can vouch for me that I know what I am doing with 70 and 71 TA's... I say this because last time I tried to give advice on a '570 Quadrajet I was crucified by a majority of that thread participants-never realizing I'm the guy who ever 7 figure Pontiac 's carb have been restored by me...currenty have the 69GTO RA% and probably the last 70 blue RAIV's carbs here for work.. Just try my solution before you go out and spend a couple hundred dollars on a new starter when you don't need it..

[70RAlll]

I just re-read your original post.. Make sure you put a spring that is 1-1 1/2" longer and stiffer in that solenoid.. This will solve your problems.. If you have bought new rebuild starters, the commercial shops often reuse the original springs.. Especially since many have moved to Mexico.. I agree I would put a quality VOM on the positive connection at the solenoid, turn the key and see if it is getting 12 v..I bet it is..

[tsmith455]

I really appreciate the replies. If it were the spring...which I did replace, and measured, even if it were weak....wouldn't I hear the clicking sound of the solenoid? When this happens...its nothing. I have wrapped the entire positive cable and starter wiring within 1.5inches of the terminals with "cool tape" insulating tape. I also have a factory heat shield on the solenoid, and still have the issue. I also examined and wrapped any wear spots with rubber hose, thinking the positive cable could have thin insulation somewhere and be grounding out and losing voltage. I am beginning to think its an under dash wiring issue also, however baffles me on why it happens after I have been driving it....and the car is hot. I don't understand what would get hot under the dash that would cause an "open" in the wiring on starting, however allows the car to run perfectly once started.

Also, why can I start the car with the ignition on and jumping across the terminals, however not with the key and ignition switch. Is there something in the column or ignition switch that could be getting hot? I have also replaced the switch down on the column when this all started as well.

I seem to not feel like its the starter......just not sure what to replace next.

Thank you,

Tom

[SD73]

Tom, those starters are funny things. I don't think it's the starter either since you've already replaced it. Sometimes they get flat spots that'll cause situations like you've described but again if you put another starter in there you should be good. As another test if it happened again you could try the old hit the starter with a hammer trick. But I think your time would be best served with a wiring diagram and testing the wiring back all the way up to the key. Age, heat, and general wear and tear will cause all sorts of gremlin like issues. That neutral start switch should not be part of the problem though. And yes, by bypassing the power directly at the starter you're eliminating the entire ignition circuit. That's why I indicated using a volt meter at that start when it was happening would help you identify the color wires you can start tracing back to narrow your problem a little. Also if you put the voltmeter on the wires when the problem is happening and you confirm power then you could suspect yet another bad starter, which in the days of Chinese made crap is still a possibility.

[70RAlll]

Originally Posted by tsmith455

I really appreciate the replies. If it were the spring...which I did replace, and measured, even if it were weak....wouldn't I hear the clicking sound of the solenoid? When this happens...its nothing. I have wrapped the entire positive cable and starter wiring within 1.5inches of the terminals with "cool tape" insulating tape. I also have a factory heat shield on the solenoid, and still have the issue. I also examined and wrapped any wear spots with rubber hose, thinking the positive cable could have thin insulation somewhere and be grounding out and losing voltage. I am beginning to think its an under dash wiring issue also, however baffles me on why it happens after I have been driving it....and the car is hot. I don't understand what would get hot under the dash that would cause an "open" in the wiring on starting, however allows the car to run perfectly once started.

Also, why can I start the car with the ignition on and jumping across the terminals, however not with the key and ignition switch. Is there something in the column or ignition switch that could be getting hot? I have also replaced the switch down on the column when this all started as well.

I seem to not feel like its the starter......just not sure what to replace next.

Thank you,

Tom

Tom-
I guess I should have said this another way.. STOP BUYING parts.. If you have all new wiring, new starters, new springs etc.. There is a simple problem somewhere..the design of these cars, even 40 odd years, if restored with new parts will operate perfectly well without shielding, tape etc.. . Check to make sure you bought a wiring harness made for your exact car...I know the automatics had a circle around the column, just forward of the steering wheel, that if your linkage was not set right, when you put in park the car would not start. I could grab it turning it counter clockwise,which should be fully in Park, and my car started right up. I just had to adjust the length of the rod that drops down from the steering column near the firewall and brake booster. Cannot recall if manuals have thi, think not.. but it is just an example of what appears as a problems ends up being a simple fix.. I truly believe you will find this as I have.. I cannot tell you,and sure others here have done the same, how many times I have bought part after part thinking(hoping) to correct a problem..

Hope this helps.. sounds like your car is ok, just something is crossed or possibly you have the wrong harness?