I have an 86 XT 1.8 non-turbon MPFI that is giving me fits. I overhauled the engine 2 years ago, and everything has been working fine, until lately when I have been having trouble getting it started in the mornings. I have to crank and crank and finally one cylinder will kick in and then gradually the engine comes up. Once it is up and running it runs ok, no driveability problems, and I can restart with no problems. It seems like the issue is related to the outside temperature, and it seems to have a pattern where if the weather is very warm (+90) it starts ok, but around 70 or so (like in the morning) I have the problem.
The ECS light doesn't come on, and it doesn't flash a code. I ran through the ECS diagnostic program that is described in my Subaru factory repair manual, but it says everything is ok.
Checked the compression on each cylinder and it seems ok.
I checked if it was getting a spark when it wouldn't start, and it was so the ignition seems to be ok.
Can someone give some advice on how to troubleshoot this problem? Thanks so much in advance for any help!