5.3 surging when driving or in park/neutral and reving
#1
TECH Resident
Thread Starter
iTrader: (5)
Join Date: Nov 2006
Location: Houston
Posts: 780
Likes: 0
Received 0 Likes
on
0 Posts
5.3 surging when driving or in park/neutral and reving
I'm trying to diagnose a problem w/ a 5.3 truck engine that is in in a Jeep wrangler. It is running a flashed F-body PCM running the 5.3 program.
When you rev it to about 2k + it revs somewhat smooth but you can hear a change in tone every half a second
when you go to drive it, it bucks/surges and sometimes wants to die (mainly when you arn't on the gas and then give it gas)
I've check for vacuum leaks, I'm not perfect, but I'm sure I have cleared up any vacuum leaks. I checked the fuel pressure and it is getting over 50psi. I also switched out the throttle position sensor w/ one off another engine and it still does the problem. I also switched the MAF on it- still does the problem
what do you guys think I should do? could it maybe be one or two bad coils? anyone know how to checked the coils?
let me know anything you guys think I should try and I will, I need to get this thing fixed!
When you rev it to about 2k + it revs somewhat smooth but you can hear a change in tone every half a second
when you go to drive it, it bucks/surges and sometimes wants to die (mainly when you arn't on the gas and then give it gas)
I've check for vacuum leaks, I'm not perfect, but I'm sure I have cleared up any vacuum leaks. I checked the fuel pressure and it is getting over 50psi. I also switched out the throttle position sensor w/ one off another engine and it still does the problem. I also switched the MAF on it- still does the problem
what do you guys think I should do? could it maybe be one or two bad coils? anyone know how to checked the coils?
let me know anything you guys think I should try and I will, I need to get this thing fixed!
#2
TECH Fanatic
iTrader: (4)
Join Date: Mar 2004
Location: Fairfax, VA
Posts: 1,597
Likes: 0
Received 0 Likes
on
0 Posts
Scan and tun software? Could be a anything honestly...vacuum leak, fuel trims out of wack, air leak, spark tables out of wack, IFR out of wack, A LOT of possibilties...scan it and post it and your tune
#3
TECH Resident
Thread Starter
iTrader: (5)
Join Date: Nov 2006
Location: Houston
Posts: 780
Likes: 0
Received 0 Likes
on
0 Posts
I wish I had tuning software, the only scanner I have is OBD. Everything is normal with everything, except the oxygen sensors ST FTRM1 and 2 are jumping all over the place (going from -35% to +35%) I think the problem rests in the fact that it is a F-body PCM that the 5.3L program was put in. I think something got messed up with the tune
Thread
Thread Starter
Forum
Replies
Last Post
05GMC4.8
GMT 900 Trucks General Discussion
5
08-07-2015 09:55 PM