[jimberg]

Originally posted by Stang_ROTY:
The car did come with the stock EFI harness so I do have the TFI unit and it is plugged into the distributor.

Okay, I guess I remembered wrong. I thought I read that you were using a separate ignition.

Also, I called my Edelbrock guy and he verified for me that my heads do have the passages already machined in so I do not have to remove them.

It's not the heads that need to be machined, it's the block itself.

As far as the water pump is concerned, I have a Edelbrock Victor high flow pump but if it isn't turning at the speed it was designed for (due to the pulley) than it's basically a normal flowing pump.

A stock pump with regular pulleys should be enough to keep your engine cool, or at least out of the ranges you're hitting.

Regarding open loop mode, won't the comp. stay in open loop without a thermostat?

No. It bases it on the temperature of the coolant provided by the ECT sensor. Your temp is rising to the range that the computer expects.

It would be cool if there was a way to hook up a little LED to indicate whether you are in closed-loop mode or not.

Any fault that would force open-loop mode should show a check engine light or at least generate and store a code.

And is it true that a lean running motor creates more heat??

Yes. When you're at cruise the computer will try to maintain a stoichiometric ratio of 14.7:1. The heat from this isn't a problem, though, since RPMs are low enough to give the cooling system time to remove the heat.

If, however, you try to maintain a 14.7:1 ratio under load and high RPMs, the combustion chamber (and the rest of the engine) will get real hot which would prevent some of your potential air flow. We make our best power at about 13:1 or lower because the rich air/fuel mixture keeps the combustion chamber and intake temps down allowing for a denser air charge.

The only way you are running lean is if you are stuck in open loop mode. Especially at idle and normal cruise.

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351W 89 Mustang GT Convertible