Hey Folks, I'm newer to V8 Buick so bare with me. Got a 70 GS 350 w/ Air which I just got running. When the car is cold it will start just fine but if you get it warmed up like idle for 15-20 minutes or take it around the block a few times and shut it off it will not start back up. It seam to me that there's no spark and cranks slow. On ocasion while on a short drive it started running rough then cut out and wouldn't restart until I let it sit overnight. I've replaced battery cables and coil with no luck. It has a newer cap and rotor. Could this be the condenser under the Cap? Any help here would be greatly appreciated. As with most of you my budgets tight and I don't really want to just start throwing parts at it until it's fixed. Hoping someone has had the same issue at one time and knows the fix. Thanks Matt
just a thought but is the choke opening as car warms up? if you have spark to start the car you should have enough to run the engine, right?
Is it that the engine won't start, or won't crank? If it cranks very slowly, or hardly at all when hot, that's heat affecting the starter. Your initial timing could also be too high. Could also be vapor lock combined with a tired starter. Does the motor run hot, and does it have headers. Do you have an HEI (Big cap ) distributor? Are you getting 12 volts to it?
I'll try to answer the questions. First off to the best of my knowledge it's a stock 350 no headers. No, the motor doesn't over heat I was just trying to say that at operating temp I have this problem. I could check the choke spring in the intake and maybe watch for movement the next time I run the car. The starter will crank when this problem happens. It's a little slow but should be more than enough to fire the engine. I can check the timing again but this was hapening before I adjusted the timing about two weeks ago. I haven't really had the car running before this point. o No:
Did you tune it up? Replace plugs, wires, and cap? If not, that is the first place to start. Also, is the gas in the tank stale? Has it been sitting for awhile?
Did cap, rotor, plugs, wires, and coil prior to start-up. Fresh gas too. I also changed the battery cable to the starter. Checked negative cable but didn't replace. Battery strong and thye charging system is working good too.
Get a helper and a volt/ohm meter and check the available volts at the + side of the coil while cranking when hot, you should have battery voltage while turning over. Could be solonoid trouble because that's where your coil is energized from when the key is in the start position. Power comes from the I terminal. Dave Berry
I appreciate all the comments. Dave, you led me down the right path to solve my problem. I checked the voltage from + of the coil to the - of the battery with the ignition on. 5.7 volts. Car won't start! I ran from the battery + to the coil + with a jumper and she's ready to shread the hides. Now if I understand this correctly you shouldn't have a full 12 V at the Coil + but actuall 9.5 or something close to that. The wire running from the starter to the coil + is some kind of resister wire that cuts the voltage down. This is what's bad on my GS. What is this resistive wire called? Where can I get this wire or is it as simple as getting a new 12 gauge wire in series with the correct resister to knock 12 volts down to 9.5 volts?
It sounds like it is two wires that are bad. The resistance wire come from the main motor plug on the firewall (brown wire that is wraped differently that the rest of the wires). If your wiring under your hood is orginal than you should have a yellow wire coming from your starter (R terminal) to your coil +. During cranking of the motor 12 volts is sent to the coil by the yellow wire, When you release the key (in the run position) voltage then gets to the coil by the resentce wire (about 9.5 volts). You should have 12 volts while you are cranking the motor and about 9.5 volts when the key is released. The wire from the selniod is not a resistance wire.
Michael, thanks for the information. I currently only have one wire to the coil+ and it's red. If I am understanding what your saying I should have two wires. One from the firewall and one from the starter. ou:
So it's the R terminal, thanks Mike for the heads up and the pic, actually been looking for that myself for a while. Do those wire color codes stay the same from 70 through 72 Skylark/GS. Now Matt the wire from the solenoid comes up in a harness and is spliced into your coil coil wire somewhere in the wiring harness running accross the valve cover. From that point one or the other source is feeding your ignition. While cranking the R terminal at the solenoid supplys battery voltage to the coil, and when the key is resleased to the run position the resistor wire supplys the power. You need to check your voltage to the coil while cranking and see what that is too. Both of these will have to be fixed for your car to operate correctly. Good luck!! Dave B
I tried to put a temp fix using a balast Resister which would take 12 volts from the ignition and kick it down to 9.8. This didn't work, car still won't start. In run I had the correct voltage on the coil but still wouldn't run. Dave, I'll try to track the original wire back to the firewall or where ever it meets the other wire to see what I can do. This weekend is shot for me and I won't be able to get back to the car until Thursday. I'll let you guys know what I find out. Anyone close to Wickliffe Ohio who might be familiar with this and could stop by?
won't start when hot All standard four stroke motors need more fuel when cold which is why carbs have chokes.....to restrict air flow and produce a richer air/fuel mixture. As the engine warms the choke should open to allow a leaner mixture. It is possible that your carb is set to run to rich causing your spark plugs to foul. In combination with weak coil field would leave you sitting for a while. Try keeping throttle plate open with a screwdriver for a few minutes then cranking it over. If it starts, remove screwdriver before RPM's get to high or you'll over rev and cause serious damage, that is proof of to rich. Check float level, Idle/Air mixture, rods/jets, etc. If not the problem, do you have mechanical fuel pump? If so and it is old/ worn-out they loose pressure when hot. Causing a vapor-lock situation. Hope that helps! Ryan in Wyoming
Great News! I'm on the road again! Thanks to everyone for their input, if it didn't directly fix my problem it gave me insight into other areas that I wan't clear on. Okay for my temp fix the Balast resister works. Long term will be to get the correct resister wiring replaced. The new Points and Condenser were bad out of the box and giving me the additional no spark issues. New set took care of this issue. I was running rich so I leaned the carb out a little and readjusted timing.
