The engine in my '86 T/A is from a '91 T/A. The '86 intake base isn't compatible with the '91 heads so I used the '91 TPI as well but I'm still using the '86 harness and ecm. I have almost everything with this swap sorted out except one thing. On the '86 intake base there is a provision for a large temp sensor with an injector style plug on it that I'm told is the coolant temp sensor for the fan. The '91 intake doesn't have this provision. Is there a work-around for this or another location for the sensor? There is a threaded hole in the pass side head that will accept the sensor, but it is right below the headers and I'm thinking it will get very hot! Anyone got any ideas?

 

That is the cold start switch, for the cold start injector. Without it, might have hard starts but I've run a car without one hooked up before.

 

The T/A isn't going to see any cold weather driving and the '91 TPI has no 9th injector so I guess I'll just plug that hole. There is another smaller temp sensor in the front of the intake manifold and one in the driver side head as well. What are those for? I'm guessing one is for the gauges and one for the fan? Doesn't the ecm need to know the coolant temp as well?

 

the sender in the dr head is for the guage, the coolant temp sensor is on the front of the manifold, if you have a fan switch it would be in the pass head, but you may not need it if your car only has one fan.

 

You just elongate the two center holes on the intake to suit the different bolt angle and use washers or angled spacers .Plenty have done it
In any case if you got a memcal or tune from a engine without the cold start injector it will have the correct cold start fueling programmed in

 

Wouldn't all '165 ECM memcals have the cold start injector programmed in?

 

'89 '165 had no CSI and start up enrichment was done on the programming adding extra fuel through the injectors

CSI control is from the standalone switch at front of intake that you mention; is not connected to ECM .
Simple switch arrangement .Engine cold it adds fuel through the cold start injector when cranking; engine over a certain temp it doesn't