EFI engine wont start
EFI engine wont start
Yo all,
I have an 88 F250. Drove to work. Went to leave, started for 5 seconds and quit. Has not started since. Had it towed home.
Checked fuel pump output downstream of filter. Fuel pressure and flow. Connected pressure gage at fuel log shows 40 psi. I have spark at the coil out put wire into the distributor. Timing appears correct #1 near TDC.
Engine will not fire at all unless I spray starter fluid into the throttle body, wants to run on the starter fluid, but will not fire at all without it. Spark plugs bone dry. Seems to be lack of fuel, but I show 40 psi at the log. HELP!!!!
88 F250
99 4X4 Ranger
64 427 Fairlaine
I have an 88 F250. Drove to work. Went to leave, started for 5 seconds and quit. Has not started since. Had it towed home.
Checked fuel pump output downstream of filter. Fuel pressure and flow. Connected pressure gage at fuel log shows 40 psi. I have spark at the coil out put wire into the distributor. Timing appears correct #1 near TDC.
Engine will not fire at all unless I spray starter fluid into the throttle body, wants to run on the starter fluid, but will not fire at all without it. Spark plugs bone dry. Seems to be lack of fuel, but I show 40 psi at the log. HELP!!!!
88 F250
99 4X4 Ranger
64 427 Fairlaine
Spark plugs bone dry after checking for fuel psi leads me to believe that the PCM/ECM sees WOT when it doesn't exist. Try unplugging TPS sensor and try to start it. WOT shuts injectors off to prevent flooding.
My 89 did this once. Ended up being the ignition module in the distributor. It would spark enough to light the starting fluid (just barely) but not enough to light the gas. Replaced that and fired right up. I did all the usual checks and found all the same results you have. I know you can check the module in the truck but I can't remember how.
Depending on where you live, your engine computer could be corroded to the point that it won't tell the injectors to open. That happened to me and a $50 junkyard engine computer solved my problem. Check the computer case and if it looks at all corroded / rusty then it may be worth looking into.
What is WOT ? and TPS sensor?
Uncertain what WOT is of the 8 sensors which is the TPS?
WOT-Wide Open Throttle
Also similar when you have accelerator pressed to the floor. It does the opposite of our carbed days.
Also similar when you have accelerator pressed to the floor. It does the opposite of our carbed days.
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Dry plugs
My 89 did this once. Ended up being the ignition module in the distributor. It would spark enough to light the starting fluid (just barely) but not enough to light the gas. Replaced that and fired right up. I did all the usual checks and found all the same results you have. I know you can check the module in the truck but I can't remember how.
Lastest update
Thanks for the above input, I removed the TPS connector and tried to start it. Same results. None!
I attempted to get the KOEO codes but the check engine light has never worked. Still doesn't. Hooked up the volt meter as per the Haynes Manual. Showed battery voltage. Turned on key, voltage dropped to 5.17 and varied between 5.16 and 5.18 with no discernible codes. Don't own an old analog voltmeter, had to use my good digital. Maybe the test wont work with a digital meter??? Any way no codes.
I removed the computer and found some minor corrosion on both pin and socket sides. Sprayed with contact cleaner, they cleaned up OK. I'll reinstall it in the morning and try it again. I had to get the P/Ns to find another one anyway. If the cleaning did not work ( I'm doubtful ) I'm off to find a used computer.
Don't t0uch that dial!!
88 F250
99 4X4 Ranger
64 427 Fairlane
I attempted to get the KOEO codes but the check engine light has never worked. Still doesn't. Hooked up the volt meter as per the Haynes Manual. Showed battery voltage. Turned on key, voltage dropped to 5.17 and varied between 5.16 and 5.18 with no discernible codes. Don't own an old analog voltmeter, had to use my good digital. Maybe the test wont work with a digital meter??? Any way no codes.
I removed the computer and found some minor corrosion on both pin and socket sides. Sprayed with contact cleaner, they cleaned up OK. I'll reinstall it in the morning and try it again. I had to get the P/Ns to find another one anyway. If the cleaning did not work ( I'm doubtful ) I'm off to find a used computer.
Don't t0uch that dial!!
88 F250
99 4X4 Ranger
64 427 Fairlane
Problem solved
$60 junk yard computer fixed it. Apparently the computer would not send a signal to the injectors to open.
Thanks for all the suggestions.
Allyn
nice to see it resolved.
i am curious ... did you crack open the bad computer to have a look inside ... leaking capacitors are common and if you have one it will be fairly obvious when you open up the case.
i am curious ... did you crack open the bad computer to have a look inside ... leaking capacitors are common and if you have one it will be fairly obvious when you open up the case.
Glad you got it going. I can't understand why Ford put the computer so close to your feet where all the snow, salt, mud, etc get brought into the cab...
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