1984 Honda Accord – broken timing belt :(

Original title: 1984 Honda Accord won’t stay running when below 70F
I’ve had this car since January and this problem started in March, gradually getting worse every month. It has 122K miles on it. The car will not stay running when the outside temperature is below 70F. In fact, the hotter it is outside, the better the car runs – opposite of most cars. I’ve replaced all of the following:

Ignition switch
Ignition coil
Distributor (TEC), cap, rotor
Spark plugs & wires
Carburetor was rebuilt last month (damaged power valve)
Air filter

This car is ’84 so it has no computer of any sort, nor does any sort of check engine light exist on this car. No vacuum leaks. Cooling system works fine, the car has never overheated on me – although the thermostat housing leaks coolant quite a bit, so I have to refill it every couple of months. Oil was changed in December. Catalytic converter is not new, but it passed smog in March. EGR valve is ok. The best the car ever ran was on a 119-degree day three weeks ago. When the temperature sinks below 70F for a while, the car will start, but it will either stall immediately, or run fine for about 5 minutes and then stall down the road. Mechanics say something is causing resistance in the distributor, to which I agree – something is draining/killing the spark when the temperature gets below 70F. It is not a fuel/air problem, I’ve ruled that out. The stalling occurs regardless of whether gas is being applied or not, although it does tend to stall faster when giving it gas. After it stalls, it’s difficult to start again – and when it finally starts, it only stays on for a few seconds before dying again. If you try to accelerate during this short time frame, the car has extremely low power and will move very slowly, until it dies again.

During the day, sometimes I smell a strong odor of raw gasoline when coming to a complete stop. Sometimes, when going down the road, the engine will randomly misfire really badly for a second (feels like the transmission is harshly downshifting and like the car is going to stall), but always recovers immediately. The car also acts strange when you start it up after its been sitting for a few hours – it will act as though there is a vacuum leak (bouncing RPM needle, high idle, hesitation) but it always goes away after two minutes. On really hot days (110F+), this problem doesn’t occur at all.

Here’s an excerpt from a post I posted on another forum a couple of days ago, describing the last time I tried to drive the car at night:

[spoiler]Okay so last night I actually drove the car around for a while, and it stalled after a few minutes. But this was the strangest, more bizarre stall I’ve ever experienced in this car.

Temperature was about 65F outside, about 2 AM. Car ran fine for the first few minutes. I was going a steady 45-50mph on a straight, flat road with no traffic. All of a sudden, I can feel the car just beginning to slow down for no apparent reason, and my eyes quickly turn to the RPMs to see the needle very slowly sinking (from about 2200 since my foot was on the gas pedal). It was dropping very slowly – so slowly that it took about 15-20 seconds for the car to actually stall after I noticed the decrease in power. I could tell that the car was probably about to die so I steered to a safe spot where I could leave the car overnight, then walk home (only a few minutes away). But while the car was slowing down and RPMs sinking, I kept my foot on the gas pedal (not increasing nor decreasing it, just keeping it the same). I could feel less and less response from the gas pedal beneath my foot, until eventually there was no response at all.

I reached to turn on my hazards since I was still on a main road, but here’s where it gets really interesting: the hazards did not work when I hit the switch. I then noticed that the backlight(s) on my instrument panel were dimming, as well as my headlights. So now, not only was the engine slowly shutting down – but now my electrical was affected too. That’s never happened before since I got this car. There was a bit of shuddering, like the engine was suddenly running on just 3 cylinders, and then two (if that’s even possible) so I finally let my foot off the gas (which wasn’t working anymore anyway). Suddenly, my instrument panel and headlights were fine again and my hazards worked. After the car finally came to a complete stop, everything else was fairly typical. Hard starting, but eventually successful (only to have the car immediately die again within two seconds every time). After waiting a few minutes, then starting the car up again – it would start and run for a little longer, like 10-15 seconds before cutting out. Each of those times, when I tried to accelerate (limping the car down the shoulder just to see how far I could get it) – extreme lack of power. RPM would not go past 1400, and the car would move like a grandma – no matter how hard I pressed the gas. Very low power, and eventually stalling.

So I figure this episode of stalling might actually be a little helpful, just given how particularly bizarre and oddly-specific the process of stalling was. My car’s electrical being affected (lights dimming) was a first, especially since it only did that while I had the gas pedal pressed while the car was slowly dying. How extremely odd. The sheer lack of power was surreal, I wish I could have recorded it. And of course, all of this occurs within the context of the outside temperature being below 70F.[/spoiler]

I had the alternator and battery tested at AutoZone this afternoon. Both tested perfectly fine, but the “starter failed the test” according to their mechanic. He didn’t give me any more details about the specifics. The starter seems fine to me and unrelated to my stalling problem. Anyway, what could be killing the spark when the temperature gets below 70F outside? I can’t find any answers to this anywhere on the internet and mechanics are just as baffled as I am. I’ve had a couple of users suggest that there could be some intermittent ground fault somewhere on the car…