88 f150 still havin problems starting.

:banghead: I'm still havin problems with my 88 f150 4.9 6cly .
i wrote before about this truck, changed some things and still nothing.I'll try to make it short but detailed as poss. any sugg. would be great.
I had my boys in the truck when we were up in the fields we hit a rut which was deep enough to stop the truck (about 12 inches deep) when we stopped the truck stalled and would not start back up. we got it to the barn. and started lookin for the problem. we first put about 15 gal. gas in. in case my guage was not workin. we then changed the fuel pump on the frame because it wasnt running right. (the pump). tried it nothin. we then changed the filter. nothin. then checked for spark wasnt gettin nothin off the coil, we changed the coil and changed the plugs, cap, rotor, wires, dist.mod. mod. was only readin 1 1/2 which the auto shop said it should be about seven. still wont start . truck is fuel injected. we shot startin fluid in and truck will start with that but stall when evaporated. i changed the fuel regulator and checked the fuel pressure its about 57lbs. which 3 out of seven shops said that was good pressure. i even bought a ford LED. tester for computer codes but it didnt work because we had to disconnect the battery to change the fuel pump which then messed up the computer readout. I think it boils down to the fuel injector pulse wires .
But here comes the questions, how do you check the elec. pulse can I put a tester on the plug to the injector with the key on or in the start position. and where does the wires come from and go to, maybe sensors? does the computer control the pulse? Please help. :angryfire :dunno: we even checked out the reset switch behind the clutch ped. we tried it in both positions and nothin. thanks for any help.and checked all fuses , there good. pump in tank is workin too.
help!

I would say its your inertia switch. how did you check the fuel pressure? did you have to jump it or just turn the key to crank?

why would you say its the switch, we checked the pressure with a fuel pressure guage with both turnin the key and trin to crank it over , no jump.
thx.does that switch turn off the pulse to the injectors

why would you say its the switch, we checked the pressure with a fuel pressure guage with both turnin the key and trin to crank it over , no jump.
thx.does that switch turn off the pulse to the injectors
well the switch cuts the power to the pumps when your in a hard impack
no it doesnt turn off the injectors, thats what I was wondering just to make sure you didnt have to jump it. have you tried spaying some starting fluid in it just to make sure your problem is fuel?

yes , we tried to spray starting fluid in it , it will start and run until the fluid evaporates we have fuel pressure but im not sure if the pulse is workin (i dont know too much with the injectors) which i think the pulse is what releases gas spray through the injectors?

I think you need 60 to 65 PSI of fuel pressure to start that truck not saying that 57 will not do it. I would call and ask a dealership to find out for sure. Also the injector get their signal from the ECM so check and make sure the ECM is pluged in good.

yes , we tried to spray starting fluid in it , it will start and run until the fluid evaporates we have fuel pressure but im not sure if the pulse is workin (i dont know too much with the injectors) which i think the pulse is what releases gas spray through the injectors?
the book calls for 50 to 60 psi have you check the ignition mod?

yes we changed the mod, have a ?. how do i know what fuel pressure should be, when i called dealers, engine builders, parts stores, all types of garages, and everyone gives me different answers. answers were anywhere from 45lbs to 95lbs. i checked mine with a pressure guage 5 times and reads about 57lbs. "still tryin " also there are two small black boxes mounted to the side of valve cover with elec. connectors and two small hoses on each box, connections i think comes from or to injectors (elec. wire) could these be relays for pulse? also the inertia switch, we checked a switch that is behind the clutch ped. its a small black box with a red button on top. both pumps, the tank and frame still run with red button in both positions, i could be wrong but does it matter if that is the inertia switch , is bad. as long as the pumps are workin ?

you may not want to hear from me after my clutch blunder but here goes.... as i read about your problem i was screaming inerta switch!!!.. if it was doing good before the bump ... i think i would check further into that switch that is what its job is... to shut off the fuel pumps in case of an accident.... ive saw them just bump a curb in the parkin lot and shut off... but if the pumps are running then it seems the switch has been reset... just something to think about....

try unplugging the computer and battery both posts for 30 mins. then hook them back up. what about your solenid? try cranking it using a screwdriver get someone to turn the key all the way while you use the screwdriver on the 2 posts on the solenoid

Try this to see if your injectors are working or at least getting the pulse. First, get a light probe, little device you ground to the frame and when you touch something hot (has voltage) it lights up. Stick this probe in the back of the connector of the injector connector and it should light showing you have voltage. Then have someone crank the truck while haveing the probe stuck in the connector and see if it flashes. If it doesn't, try the second wire. These injectors should have a constant 12 Volts supplied to them (when the key is in start or run) and the computer turns on and off the ground. If the light does not flash at all while the engine is cranking, check the computer, grounds and wiring harnase. It would definatly help if you purchased a chiltons or hayns manual to assist in wiring diagrams if you have not already done so. I can also say that these trucks will run with atleast 35 to 40.

Anyone know why an inline 6 cyl ford would flood out after it warms up. It runs really rich and the stalls out if the rpms are not kept above 1200. Does not do it badwhile cold. Thanks

my .02....

a similiar problem occured to me with a newer model 150 fourwheelin... after countless hours, $$ , curses, and bruised knuckes cause i mistook the fender for a punching bag... it turned out to be the PCM.. what had happened waaaaaas......

the main ground cable going to the PCM had kinked/jarred or frayed loose, causing a sparking effect to the PCM... affectively sending it on a permanent vacation.... it took about 1-2 seconds for the damage to happen, took me a while to replay the event in my head..( t to mention 2 pcm's) but i finally remembered the engine was idling for 1-2 seconds after my sudden stop and then died and that was it... during that idling time... the engine light flickered which was what intially draw my attention to the dash....

also...
you check the pulse to the injector with an ohm meter.. i dont know the values required... but thats the ONLY tool you can use to check the resistance of the pulse.. the values change according to throttle position

good luck