Sorry to start a new thread but I can't seem to find the one I wanted to add to. It dealt with a problem with restarting once the engine had been warmed and had sat for a while. The consensus was that it was due to heat soak into the injectors themselves, and that on cars later than mine (1970) "phenolic" washers had been fitted at the factory to insulate the aluminum injector holders. It also noted that larger diameter o-ring seals would need to be fitted to compensate for the added space.

If anyone is interested in making this mod, you may find the cost of phenolic washers to be exorbitant (you need eight of them), I found an economical supplier: Bicknee Tattoo Supply Company. Yes, it seems like the perfect-sized phenolic washers are also widely used in the tattoo trade. And instead of $2.50 to $7.00 each, they’re just 25 cents. If you call the order in you can also get them to mail them to you for $2.00, instead of their normal $15 FedEx shipping.

As to the O-rings, I sourced Viton rings from The O-Ring Store. Viton is high-heat compatible. Their P.N was V75208 (7/8 OD x 5/8 ID X 1/8 Thick). This were 30 cents each, so I got an extra set. Shipping was $5.65. You probably need to get new cap screws because of the increased number of components. Stock is one-inch. You need at least 1-1/4”. I had to run to the local hardware store in the middle of the project and settle for 1-1/2” and then cut them down as there is limited depth to the mounting holes.

Popped the injectors out and laid them on top of the valve cover, taking care not to damage the pintels. This is a great time to clean everything up, including the injector passage into the cylinder, to check the injector washers and also to check for leaking injectors and for proper spray pattern.

I followed Phi S’ recommendation, but added a lock washer. So: bolt/lock washer/flat washer/phenolic washer/injector holder/phenolic washer.

Everything went together quite smoothly (don’t try to stick the injectors back in without first removing the washers from the holders and putting them on the injectors…and use a little Teflon lube on all the flexible components.). I look forward to testing the theory that this is the cause of my embarrassing inability to restart the car smoothly when it’s sat for 10-25 minutes on a warm day. I’ll report back when testing is complete.