Recently purchased a 1988 IROCZ with 8600 original documented miles.
What is the proper gas to use such as what octane.
I've been told 89 octane is suffice.
Thank you.

 

Welcome Aboard!

89 should be sufficient with a stock TPI. There MAY be knock under certain conditions and the EST system should detect that and retard timing to prevent damage. 91 octane should almost certainly prevent knock unless there is substantial carbon accumulation in the chambers, but at that low mileage it probably is not an issue.

If the vehicle has been stored for an extended period, the first fill of fuel probably should be the LOWEST octane of good clean fuel that you can find. Any old, stale, stratified fuel left in the system will be better dissolved and re-mixed by the lower octane (more volatile) fuel. Lower octane with ethanol might be even more effective at cleaning.

I've stored my '86 TPI every winter, usually starting it only once a month to get it to temperature. Despite using fuel stabilizer, a filled tank and other additives the fuel will begin to lose volatility to a point where at about 60 days it has a noticeable affect on operation. The first refill in spring with low octane has helped.

If you are going to store it again, I have found that preparation for storage with about 2% two-cycle oil has helped me keep the pump and injectors intact for the past 20 years. Prior to that the injectors had to be removed and cleaned twice before the car had 18,000 miles. Since then? Well, I'm knocking on wood to chase off the trolls, but it's been no problem.

 

I have always run 89 or better in mine and never had any issues.

 

Thank you very much. You answered my question and then some.