93 tercel engine issue

I have a 93 tercel that has developed a weird engine problem. It starts fine and will drive fine for about half hour. If u stop after half hour and shut engine off and 5 minutes later try to restart and it will crank over for at least 10 seconds before it restarts. After it is running again it seems to have a serious stutter and doesnt want to idle. When u shift into drive it stalls and you have to crank engine for another 10 or more seconds before it will start again, and when it does start it still stuttering and wanting to stall. If you keep foot on brake and other foot on gas it can be driven and once the car is moving over 10 mph it runs fine. Any ideas out there in cartalk land ? Ps. the wires have been changed and the rotor and the cap and also timing belt replaced. Plugs also were pulled and inspected. Showed sighns of wear but all were nice tan color and looked good.

Does your Tercel have fuel injection?
If it does, I suspect that you have leaking fuel injectors.

My guess would ne that something in the ignition system is becoming heat sensitive. When you shut a hot engine down, the temperature rises in the engine compartment as the engine’s internal temperature dissipates out the top and sides. Something that’s become heat sensitive can fail at that time. If my memory serves, this vehicle has COPs and it could be those, but there’s also the igniter and the crank position sensor that might be failing.

“there’s also the igniter and the crank position sensor that might be failing.”

Yes, the igniters on these old Toyotas were problematic.
In my experience, they usually just…suddenly suffer a total death…but I suppose that they could become dicey before they totally die.

I was a passenger in two different Toyotas of that era that suddenly died at high speed and needed to be towed, and in both cases, it was the igniter that had failed.

The thing that catches my eye is the fact that if the OP keeps one foot on the gas and one foot on the brake it will keep running. I’m suspecting the IAC (idle air control).

I have a 1994 Tercel sitting in my driveway right now . . . exact same body style and engine, but mine is a 4speed stick. And it sounds like OP has an automatic

OP’s car does not have COP ignition. It has a distributor ignition, but I believe the coil is inside the distributor, under the rotor. The igniter is external

It has EFI ignition, but not sequential. It’s batch fire, as far as I know

I’m also leaning towards IAC and maybe a dirty throttle body. I’d clean those first

Another thing to keep in mind . . . this engine does have an adjustable idle speed. On mine, after doing a full ignition tune-up, I had to ever so slightly adjust it, to bring it within specs for the last emissions test

A misfire will be less apparent once the car is driven. Meaning you’ll feel it much less, versus at idle.

I might be wrong, but I’m fairly certain this car doesn’t have a CKP sensor

It would be a good idea to tee a fuel pressure gauge into the system. I said tee because as far as I know, no Toyota engine has ever had a fuel pressure test port. Maybe in very recent years, but I doubt it. My brother’s 2008 Toyota doesn’t have one, for what it’s worth

I’m inclined to agree with a leaky injector, but I would also bleed the cooling system to make sure there isn’t an air bubble forming around the coolant temp sensor.

The only thing that troubles me about the leaky injector theory . . . OP says the cars initially “starts fine”

I’m wondering if my definition of OP’s definition of “starts fine” matches mine

But as I said earlier, teeing in a fuel pressure gauge should answer a lot of questions

Driveway diy’er here, I’ve owned a similar vintage Corolla for 20+ years. Could be a heat sensitive component in the ignition system – igniter, coil, pick up coil – but I’m thinking more along the lines of a fuel pressure problem. Pump, check-valve, pressure regulator, EVAP problem. Possibly a leaky injector, but less likely.

One thing you could try, see if it helps to loosen the gas cap when this happens. If you hear a rush of air as you loosen the cap, and it starts and runs fine then, you probably have a vacuum developing in the gas tank preventing fuel from reaching the engine.

If that doesn’t help, and a visual spark test shows the spark at the plug is ok, a fuel pressure measurement is probably next.

And if you haven’t checked the computer’s diagnostic codes, now is definitely the time to do that.