Well the temperature finally got above 60* and there the hot start is, she has been waiting for me. All winter long, she showed her face a few times in the so called louisiana "winters" but was a long gone nuisance when I got up here to illinois.

Well now its warming up and there she is ugly as ever.

Besides moving to canada does anyone have any guesses as what it could be or how I could figure it out? The difference between 55 and 60* is like night and day. My coolant temperature never gets above 186 so I doubt its something actually ON the engine. Something is getting heat soaked it seems.

I dont think its..

Fuel pump [why would 60* make a difference?]
Fuel filter
Fuel temp [tested fine..]
Fuel relay.

 

i guess I could start heating up sensors individually on a cold start?

 

still a possibility of injector [think I tested this] coil pack? I heard someone with similar exp. and it was FPR

I will, and incase anyone else has this problem unhook FPR and stop vaccum obviously, and this should increase the fuel pressure and prove if its the FPR.. ???

 

Have you checked the continuity of the wire harness between the sensors used on startup and the ECM (fuel temp, coolant temp, IAT, IACV etc)?

What kind of data can you gather with your Scangauge?

 

search for posts on the fuel temp sensor, mounted on the lh side of the fuel rail, I think recently Cosmic88 has given us some test values, to my knowledge this sensor controls fuel injector pulse length @ warm engine start-up

 

How about start with what you have checked before, when was it last tuned along with wires, what octane gas are you burning, what is your fuel pressure before and after a cold start? Be specific.

 

does anyone make a block "chiller"

If the issue is so related to ambient temps I keep thinking it may be that FTS.... I was about to search through all your recent threads to find the tested values you got from your sensors but then I thought..." just ask him"

measuring the FTS after a hot shutdown, every few minutes until it reaches ambient temps what are your ohm readings?

Like Jull mentioned... it may be worth taking those ohm readings at the ECM plug (disconnected of course) rather than at the posts on the sensor itself just to be certain the signal is actually getting back there.

 

What about Alaska?