Truck running bad

itbrokeagain · 11-22-2008, 12:08 PM

Low speeds are fine. Get it onto the highway and push any more than ½ throttle and it seems like it is loading up and backfiresd a lot. Bad vaccum advance????

78 F-150 351m T-18

Thanks!

mike shelton · 11-22-2008, 01:35 PM

low fuel prussure? !!!!!!!!!!

JasonCJ7 · 11-22-2008, 10:59 PM

Check your fuel pump and fuel filter.

itbrokeagain · 12-30-2008, 12:19 PM

Getting plenty of fuel. Took the ignition box to Autozone and they tested it and it came up as bad. Changed it and it is doing the exact same thing.

At lower RPM it runs very well. At higher, getting on the highway or getting ready to change gears, it cuts out and backfires. As soon as I get off the gas it runs fine.

Arrrrrrrrrrrg. :mad:

eighty3bronco · 12-30-2008, 07:36 PM

Almost sounds like timing to me but could it be getting too much fuel and is choking it out? What does it act like without driving and you rev the engine?

itbrokeagain · 12-31-2008, 01:59 AM

No problem. Only acts up under a load

eighty3bronco · 12-31-2008, 03:27 AM

have you checked the vaccuum at all? Check the spark plugs. I think I had that problem with my 302 at some point and it may have been the plugs.

11-22-2008, 12:08 PM	#1
itbrokeagain Just Empty Every Pocket - CORE Member - Join Date: Feb 2007 Location: Amelia Posts: 1,435	Truck running bad Low speeds are fine. Get it onto the highway and push any more than ½ throttle and it seems like it is loading up and backfiresd a lot. Bad vaccum advance???? 78 F-150 351m T-18 Thanks! __________________ 91 fj 80 on 37 Nitto Muds with a 10k winch. Cage and sliders coming soon.

11-22-2008, 10:59 PM	#3
JasonCJ7 Throttle Jockey Join Date: Jan 2007 Location: Liberty Twp., Ohio Posts: 182	Check your fuel pump and fuel filter. __________________ 78 CJ-7, 350 V8, T-18a Tranny, Twin Stick Dana 300, Scout 44's, 4.27 Gears, 36" TSL's, Welded rear and Full Spool Front, Hi-Steer with GM Knuckles

12-30-2008, 12:19 PM	#4
itbrokeagain Just Empty Every Pocket - CORE Member - Join Date: Feb 2007 Location: Amelia Posts: 1,435	Getting plenty of fuel. Took the ignition box to Autozone and they tested it and it came up as bad. Changed it and it is doing the exact same thing. At lower RPM it runs very well. At higher, getting on the highway or getting ready to change gears, it cuts out and backfires. As soon as I get off the gas it runs fine. Arrrrrrrrrrrg. :mad: __________________ 91 fj 80 on 37 Nitto Muds with a 10k winch. Cage and sliders coming soon.

12-30-2008, 07:36 PM	#5
eighty3bronco anywhere but there Join Date: Jan 2007 Location: Blanchester, Oh Posts: 174	Almost sounds like timing to me but could it be getting too much fuel and is choking it out? What does it act like without driving and you rev the engine? __________________

12-31-2008, 01:59 AM	#6
itbrokeagain Just Empty Every Pocket - CORE Member - Join Date: Feb 2007 Location: Amelia Posts: 1,435	No problem. Only acts up under a load __________________ 91 fj 80 on 37 Nitto Muds with a 10k winch. Cage and sliders coming soon.

11-22-2008, 01:35 PM	#2
mike shelton Join Date: Jan 2007 Location: waco ky Posts: 211	low fuel prussure? !!!!!!!!!!

12-31-2008, 03:27 AM	#7
eighty3bronco anywhere but there Join Date: Jan 2007 Location: Blanchester, Oh Posts: 174	have you checked the vaccuum at all? Check the spark plugs. I think I had that problem with my 302 at some point and it may have been the plugs. __________________