Question: Seems like unstable mixture problem - 95 Corolla

Hello,

I'm currently facing trying to troubleshoot a 95 Corolla which seems to ping and stutter (shake) on acceleration, I think it's alternating between rich and lean mixture (based on the dark deposits by tailpipe).

The pinging went away after switching to plus fuel octane, but it's starting to come back now despite that. The vibration in the engine during acceleration is so unusual that I was convinced that the (auto) transmission was slipping, until a transmission shop told me otherwise. It actually seemed to be happening only in 2nd gear, but I'm guessing that it has more with the rpm-load relationship.

I plan on changing plugs/wires/cap/rotor (even though I've changed them about 30K ago (platinum plugs, etc)... And then go through diagnostics on the coil and whatever else I can find in the Chiltons book...

Any other suggestions or does this sound familiar to anyone?

Thanks, Alex

Reply to
Benevolent, The
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Did you use factory or aftermarket secondary ignition components? Consensus of opinion seems quite clear that you need to use Toyota wires, cap and rotor, with ND or NGK plugs to get decent results. This seems to be the single most critical area to use dealer parts. If you already have . . . then you'll need to look elsewhere. If they're stock plug wires, you can save the cost of replacement if they read less than 25K ohms. If you can find a manual, there are resistance checks for the primary and secondary windings on the coil also. If it is, in fact, unstable fuel mixture, you might try Red Line complete fuel system cleaner.

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Reply to
Daniel M. Dreifus

Thanks for your advice.

I happened to have just bought aftermarket parts to put in there, including Bosch platinum plugs, Bord Warner Select wires/cap/rotor. (Forgot the PCV valve). I realize that they're not Toyota made but I'm hoping these parts are decent enough to do. I may be wrong.

The plugs already in there were also Bosch platinum, but I'm changing them again just to rule that out. The other components are also already aftermarket and they did work for at least 10K fine before the problems developed. I guess it's possible that they deteriorated.

Oh and I do have the Chilton's for the car, it's just too cold in NJ this week to be doing this.

Thanks for the info.

PS: I am an Amsoil preferred customer, so I'd be cheating if I went with Redline :)

Reply to
Benevolent, The

Hi, All 4 vehicles in my familiy is Japanese cars. From my experience, they don't like Bosch plugs. I always use NGK Platinum or Iridium ones. They work well. Tony

Reply to
Tony Hwang

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