truck wont start, sputters and backfires out intake! - Diesel Forum

farnereinar · 07-20-2009, 08:48 PM

i picked up a 2001 f-350 5.4 for a steal of a deal, the guy said the motor was knocking, but ran still when it was parked, 3 months ago

i picked up the truck and put in a new battery (so now i have no codes) and upon starting it wants to backfire out the intake, will barely run on ether....i can hear the fuel pump working & verified the truck has fuel

almost sounds like when my other 5.4 had mass airflow sensor problems, you can put the pedal to the floor, and sounds like it wants to fire up, but wont

any ideas? i think its electrical.....being that if im shooting either in it...its doing the same thing as if no ether..

hco4x4 · 07-21-2009, 10:33 PM

check to make sure all your hoses are hooked up. mine did the same when i had a hose off

fulltimer50 · 07-24-2009, 01:23 AM

Firing out the intake is almost always a timing or wiring problem. Check the plug wiring with the firing order to be sure they are correct. Not sure about how to check the time on the new engines, but basic timing must be the same as it always was. Check with a timing light.

akrewat · 07-25-2009, 02:15 PM

A couple of easy things to check.

Check the fuel pressure and make sure as you cycle the key a few times that you have 38-40 pounds or so at the fuel rail.

Check the red wire at the injectors, with the key on, and make sure you have 12V.

See if you can verify that the injectors are getting a signal. A digital volt meter with a "peak" setting, or set to AC volts, connected to an injector connector, and crank and see what you get.

You could also try disconnecting the MAF entirely and see if it'll start.