1987 turbo II has maybe 30 minutes of run time on fresh rebuild. When cold it starts up like a carburated car without the choke on... I have to flutter the pedal and keep the rpms up to keep it running after a minute or so it idles ok. Then once hot I have to hold it to the floor to get it start. I need ideas of what could be the problem. I am leaning toward the coolant temp sensor, or connector. Any ideas would be appreciated... It has no emmisions, throttle body mod done and new O2 sensor... if that makes any diference.
Thanks
Keith

 

could be a number of things.

Vacuum leaks
Compression
Leaky/dirty injectors
Plugs
Timing
TPS/working thermowax/etc.

 

I checked comression it is good, holds 15-20 psi vac at idle, injectors no leaky, and were just cleaned.

I suppose my timing could be off a little still and plugs possibly.

Coolant temp sensor??

 

Probably has something to do with the throttle body mod. Since all the stuff you remove when doing the throttle body mod is responsible for keeping the car running when it's cold. Not sure about the hot start problem though. I have the TB mod done to one of my FCs, and the cold-start symptoms are basically exactly the same; a small amount of throttle when cranking, some light throttle modulation for the first 2-3 minutes of operation.

 

That sounds about right. I am thinking about the coolant temp sensor being bad because it seems like it runs the cold startup map on hot starts. The CTS tells the ecu that the engine is hot, if its not working it keeps running the cold map... Causing it to be to rich... Am I right?

 

So someone searching knows, it was the Coolant temp sensor that was giving it fits. Put a new/different one in it and all is good.

 

Kinda but, you're backwards. with a faulty ECT sensor, the ECU uses a default value of 180 degrees and spits fuel accordingly. so when you car is cold, it's running a "hot map".

 

Both carburetors and fcs use the pedal on the floor as a deflooding method.

Is your afm in spec?