I have a year 1989 5.0L EFI that will crank for days but refuses to turn over. I've been working on it for about 8 or 9 months now returning the engine to stock conditions, I've pulled the engine twice and replaced almost everything besides the pistons crank and camshaft. It does however have new heads pulled off of a 302 mustang (don't recall the year, believe it was mid 80s). All gaskets are new, most of the sensors are new (o2, MAP, TBP, PIP, IAC), EGR valve and the pipe line that runs into the lower intake manifold is new, and a couple other things. The main ones are the timing chain and gears are new and the distributor cap is new, aswell as the plug wires. everything else was on the truck and it was running, reason i took the engine out again was to change the timing chain and gears.
Now that you know what work has been done I'll tell you about the problem. She cranks with no problems but will not start. I've gone through the checklist and I have the basic three; air, fuel and spark.
I checked the spark on the coil wire and got a good visible spark, I then check cylinder #1 spark and that was good too.
I have fuel pressure and the electric pump primes just fine. I checked my injectors and injector pigtails with a multi meter and both read good. Also even after checking that I sprayed starter fluid into the intake and attempted a start with no luck.
Timing has been double, triple checked, firing order is as follows: 1 5 4 2 6 3 7 8. Rotor on the distributor spins good aswell.
Ran a compression test too because I couldn't find a problem, all cylinders were between 135-145 psi besides cylinder 6 which ran high at 158 twice, only thing strange with that which is somethin to look into but I don't think that's the reason shes not starting.
I've hit rock bottom here gents and I'm hoping somebody has an idea of whats goin on, somethin I've missed or some magical start my truck juice. Please ask questions if I left somethin out or if I need to clarify and I'll get back to you as soon as possible. Thanks much -Ben