Need some help with no start- really stumped
93 GC 4.0L. 300K+ miles. Was running great, no symptoms, just passed emissions, then a week laterwouldn't start. Cranks over fine and tries to start (gets a few combustions-- like you get when flooded). OK compression, 38 psi at rail, confirmed hot spark, new and tested CPS, tested both ASD and fuel pump relay, tested cam position sensor (so know rotor is moving), coil, plugs, inspected rotor and cap, no wobble on distributor shaft (aftermarket distributor installed 50K miles ago). TPS and NSS switch test OK and security system seems OK. PCM is alive and seems fine. Only error codes are usual 12 and 55 (but I disconnected the battery as part of the testing early on). I've let it sit overnight as thought was flooded, but no help and the plugs look dry. If I pump the pedal while trying to start I can smell gas so it's getting gas. The only suspicious thing is when checking spark, it seems that I get a spark only every second or so, which seems way too slow. The starter is kicking it over at normal rpm. I even sprayed some starter fluid in the throttle body with no effect. I'm out of ideas other than just start replacing things. Any thoughts? Thanks!