Hard start when hot

[mroth]

I have a 1968 Camaro with a mild 350 and headers. I was out on a hot Sunday cruising to a local car show. I parked it and came back about 20 minutes later. When I tried to start it was almost like I had a dead battery and would not start very well. This happens a lot when hot but will start fine after letting it cool down for about an hour. I initially thought it was from the starter being hot from the headers but a buddy at work thought that my timing affects starting. I am running about 20 initial and around 38-40 total timing here at mile high Colorado. He uses a knob to set back the timing through an MSD 6AL box in his street rod. Any suggestions on what could be the problem. I plan on trying to set back the timing a little this weekend.

Thanks

Mike Roth from Denver

[Marty G Cars]

How about vapor lock from your fuel line getting too hot?

[parsonsj]

I'm betting vapor lock too.

[mroth]

I would think that it could be that but if I can get the motor to spin over it will start up. I always thought that vapor lock would still turn over the motor but just not start??????

[PonchoJohn]

This is the typical GM hot start issue.
Your timing can and does effect starting, but I'd be willing to bet that if you clean and tighten the terminals, battery connections, and especially the grounds, it'll start much better.
Start w/ these simple things. If it doesn't improve, come back for more.

[novanutcase]

How old is the battery and how much load do you put on it?(i.e. Do you have a big stereo system?)

John

[Yoda4561]

Headers are overheating the factory starter solenoid. Happened to me after I installed headers on my 72 cutlass. I bought a remote starter solenoid kit and had it installed by my mechanic, no more hot start issues. You could also try some heat wrap on the headers or fab a heatshield for the starter.

Edit: The kits like the one available from summit work great with a factory starter, apparently aftermarket starters may not work with the kit's wiring setup. This page seems to have some good info on that issue. http://www.novaresource.org/starter.htm

[MrQuick]

I agree. I would put a high quality mini starter in it and make sure you have a good connections at the positive and ground sources.

['70rs]

I believe it is heat soak from the headers. If your engine is "mild" the timing should not be the issue. The cheapest and easiest fix is a starter shield or wrap. Try that first. A remote solenoid is also a good idea as is a mini starter but you may not need to spend the money.

[79-TA]

I had this exact problem with my Trans Am. If the starter didn't get things moving right away, the battery would lose its edge and I'd be toast.

The problem was my engine was and is still a pretty fresh (read tight) build with tighter tolerances and a higher compression ratio. When hot, it was much harder to turn over than stock. The other part of the problem was the starter itself, the solenoid in particular, getting hot. When the hot start problem first arose, I could often fix it by tapping on the starter with a wrench.

For my first attempt to fix the problem, I replaced the battery thinking maybe just a little more "umph" would be enough to get things started when hot. When my shiny new AC Delco battery didn't do the trick, I stopped messing around and bought a high-torque ministarter. An original style starter tries to make grunt with a large number of coils. The mini-starter revs much higher and then gears down to multiply torque which results in much more torque than an older unit's blunt approach. Since I made the swap, I have had no issues with my car starting whatsoever. And to top things off, the mini-starter is lighter, so I saved a bit of weight too.


While this worked great for my car, you should still look into heat shielding as mentioned above. A mini starter will cost over 100 dollars. No longer routinely getting stuck at the gas station made it one of the best 150-ish dollars I ever spent. (I bought mine for 20% off when Classic Industries had a sale . . . which they are having again now, just mention it while ordering on the phone)


Conclusion:
High-torque mini starter = definitely worth a try.

[justasquid]

I had a bigblock in an 87 monte carlo ss that gave me the same issues. Turned out to be a bad ground to the engine, or I should say, not a sufficient one. but all good advice so far. a good amount of items to try.

[ProTouring442]

OK, here's how you fix it, and fix it for good...

1. Install a high-torque mini-starter

2. Install 1-gauge or larger battery cables (both).

3. Make sure you have a good battery.

Before the mini-starters came out, you had to go with even larger cables, but since they have become so commonplace the larger (0 or 00) cables are no longer necessary.

Shiny Side Up!
Bill

[shizzy]

I had the same issue on my Cutlass after putting headers on it too.

0 gauge cable, fresh fat ground strap between the block and frame and a remote solenoid cleared it right up.

BTW, the remote solenoid was done more to simplify pulling the starter due to tight clearence with the headers. Now I can simply disconnect the cable to the starter up top and drop the strater instead of having to lower the starter and then try to disconnect the wires while holding it with one hand and holding the header out of the way with my knee.

[Taylor1969]

I would check the battery. My dad had the same problem. Changed starters, put heat shield, ect. Finally he swapped batteries and it fired right up. Ended up that his alternator wasn't fully charging the battery. In the end he swapped to a high output alternator and the problem has completely gone away.

[mroth]

Thanks everybody! This is the first time I have ever used headers on a car due to the bolts coming loose. I found the right type of bolt to keep them tight but now I am experiencing the problem which I suspected was caused by the heat of the headers. I will check connections first and then work from the cheapest fix first. I am running a mini starter on my big block in a 67 Camaro and hopefully will be OK with that. I will make sure to run 1 awg wire to the starter for sure.