91 f150 xlt lariat 2wd 302 5.0 v8 started a bit weak as I drove off my battery light came on and truck cut off. It will turn over strongly but not start. Plenty of power to everything

Tried starting it again and noticed that the fuel pump was not turning on..
this is not true done wrong,
and spark is first never ever fuel first, fuel does not burn lacking spark (gas)
if spark is bad on all spark plugs then fix spark. (all plugs dead)
you really really need to end that fixaction on fuel, spark is bad
the pump only pumps cranked and running not key on
most do a 1second prime most noobs never see or know how to find that out (a fuel pressure gauge is that tool) (a 2 man job)
one at key, 1 at gauge, or voltmeter at pump wires rear. 2man not 1 or learn to crank and see fuel pressure good
and learn this fact, too, the ECU on all cars made cuts fuel if the ECU brain detects spark loss to end crash and burn as seen on TV>
this is done 1 or 2ways or both cuts injectors and cuts the pump dead , on newer cars crash switches cut fuel too, so 3ways
end fuel , deals back to SPARK


its bad wiring for spark and using a voltmeter to the correct spot when spark fails is the only test to do.
91'F150 Pickup, not econoline 4.9L gas.
it has a distributor or TFI-I or TFI-iv system
the ICM must be thermal pasted new install or fails hot.
the SM book shows it has TFI spark. in the real 4.9 schematic.
lets focus ******* TFI 4.9L
AS YOU CAN SEE , ANY OF ALL THIS CAN FAIL AND DO THIS OLD.
BEST IS NEW FULLY LOADED DISTRIBUTOR THIS OLD !
Tests:
1: the red wire must be hot keyon, at spark lost or BINGO1
2:the ecu detectS spark loss at pin 4. input. and cuts fuel faST.
3:The TFI IS the ignitor acts like old points did it charges up the coil then fires it.
4: spark is lost we always check for spark directly at the COIN.
if dead there we know coil bad or all part to the left and below bad.
5:the red/light green wire must also be 12vdc hot keyon,
6: the noise cap not missing ,dead or bad or noise can make the TFI module misfire or act up at random, noise is not good here.
7: that is for power loss etc. the problem seems like wiring bad./loose., if spark is good at coil say so. as it might be and only the ignition suppressor is bad and this cuts fuel dead if bad.
the supressor name is not good, better is spark detection read back filter. if bad ECU CAN NOT SEE SPARK HAPPEN
heck it can even lost or its pins rust after 31 year on the road.


FULL SIZED HERE

https://imgur.com/a/5wCgHKp

FIXYA MESS BELOW.

I would look at the exhaust manifolds on the engine from under the truck. Look for exhaust soot that may be coming from a crack.

Have you checked the battery? That's what it sounds like to me. Classic symptoms. You battery has enough juice for the accessories but a LOT is required to crank the engine. If your battery is weak it won't start. Try jumping it, see if it starts. If so, you need a new battery.

Do you have power at the wiper motor ?

Check the modules. And fuel pump

Had a problem like this before and it was the computer..But you could faintly smell something like burnt wires..The computer should be down by the kick panel on the driverside..See if you smell anything on that side

There is a small voltage regulator in side the dash that controls the gages its on the back of the instrument panal over the speedometer you need to remove the panal to get is it conects almost like a 9 volt battery that the conector likes like but its a lot smaller in side

what is the 8th digit of the vin

U are going to have to replace the fuel pump, the pump is located in the fuel tank.

Here is a link that might be relevant for your problem although its Mazda truck, but give it a shot:
http://www.fixya.com/support/t659042-truck_start