Changed fluids, now crank/ no start

1987 Ford F150 v8 5.0 302 automatic, 123k miles

After a lengthy struggle to get the truck running reliably, I’ve been driving it daily for 2 months. I had 20w50 oil for about 1000 miles, then yesterday I changed the rear differential fluid, atf fluid, fuel filter, and oil (10w40) with filter. A few hours passed and I went to drive it, and it cranks but doesn’t start. Swapped the ignition module and ignition coil with the spares, still no start (swapped them back after attempting to start). Unplugged the map sensor and tried to start with no luck. It cranks just fine (smacked the starter just in case it was stuck), the fuel pump primes and the relay clicks. The cap and rotor are fine, no moisture or cracks. The only thing I can’t really check for is spark, as I don’t have anyone to turn the key. Any ideas? It was running so we’ll up until yesterday morning’s fluid changes

Spray some starter fluid into the intake and see if it sputters. This will indicate if you have duel delivery problem. Changing fuel filter, maybe something got messed up there…

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I actually changed the fuel filter after I found out it wouldn’t start. I’ll give the starting fluid a shot and see

If there’s no spark, it can be caused by a faulty pick-up coil in the distributor.


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That part has been replaced already and is functioning. This literally happened after changing the oil yesterday. It has driven perfectly well until yesterday morning when I changed the fluids

Was able to check spark, it has spark at the plugs and ignition coil. Also detached the fuel line before and after the fuel filter and primed/ cranked both ways, and gas sprayed out

Swapped fuel pump relays. Attached a cheap fuel pressure tester and was getting no fuel pressure, but the shrader valve leaked a little gas when I removed it. The fuel pressure regulator was dry when I removed the plug attached to it

The dash gauges are all working. It shows that I have a quarter tank of gas and the oil pressure needle rises while it cranks

That really makes no sense. Why would you hit a starter that was already cranking?

At any rate if you have no fuel pressure, that’s your problem. Dribbling a little gas out of the valve does not mean you are getting adequate gas. If you are saying the fuel pump is running (are you sure?) go back and check your work. Do you have an open fuel line, crimped line, etc. I once took the seats out to shampoo the carpet and somehow pulled the fuse to the computer. Cost me a tow and an hour of diagnostic time to find the missing fuse.

I talked to my mechanic and tried the starter fluid spray. It fired up and died. Repeated a few times. I guess that’s now the diagnosis. I don’t know if I screwed something up or bumped something, but I’ll find out the diagnosis soon

Take a rubber mallet and bang on the gas tank and then try starting the engine.

If the engine starts, the fuel pump is going out.


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