Who ever can help diagnose my problem I will paypal you $10
10-10-2009, 02:33 PM
#1
Who ever can help diagnose my problem I will paypal you $10 Got your attention didn't I lol
Breakdown...1993' Z28, Sputters and sounds like a cam when im at idle, but goes away when cruise. Sometimes it randomly shuts off, and during a WOT run it kinda breaks up a bit then clears up.
Fuel pressure is at 42psi idle and WOT 54psi.
Has the following new parts.
Opti
Coil
ICM
Wires
Walbro pump
Racetronix harness
O2 sensors
Only thing I havent changed is the plugs...But there only couple months old, but there getting replaced regardless.
Breakdown...1993' Z28, Sputters and sounds like a cam when im at idle, but goes away when cruise. Sometimes it randomly shuts off, and during a WOT run it kinda breaks up a bit then clears up.
Fuel pressure is at 42psi idle and WOT 54psi.
Has the following new parts.
Opti
Coil
ICM
Wires
Walbro pump
Racetronix harness
O2 sensors
Only thing I havent changed is the plugs...But there only couple months old, but there getting replaced regardless.
10-10-2009, 02:39 PM
#2
Banned
iTrader: (8)
Join Date: Jun 2007
Location: san fernando valley, california
Posts: 3,093
Likes: 0
Received 1 Like
on
1 Post
have you checked for any vacum leaks? could also be a clogged injector if it also misses when its a WOT. try disconnecting each injector while the car is running and see which one makes the least change in rpm when you are disconnecting the injectors, maybe you can pinpoint it to 1 cylinder that way. i had the same symthoms when i had a cracked #4 spark plug porcilin, it still had spArk to the cylinder but it was a very weak spark.
10-10-2009, 05:08 PM
#7
TECH Addict
Join Date: Jun 2009
Location: Tulsa, OK
Posts: 2,012
Likes: 0
Received 0 Likes
on
0 Posts
Trending Topics
10-11-2009, 07:56 AM
#12
Why is your fuel pressure so high? It should be 43.5 psi at WOT, and around 39-40 at idle. For example if you are running 24# injectors, the system is feeding enough fuel for 27# injectors. So, if you are tuned for 24# injectors, your ECM fueling tables are off, which can cause most of the symptoms you are describing. Put a scanner on it and look at your BLMs, they are most likely off.
10-11-2009, 09:34 PM
#14
I have one wire that is literally 3-4mm away from one of my pipes, but I know it cannot ever touch it no matter what and its perfect, not discolored or melted at all.
...is your maf clean....
.
10-11-2009, 10:11 PM
#15
Maybe that wire is bouncing into the pipe after its hot. Even if that isn;'t the problem....get that wire completely OFF the pipe and make sure it never is able to touch a pipe while driving. If its melted, you know for sure its touching the pipe.
I have one wire that is literally 3-4mm away from one of my pipes, but I know it cannot ever touch it no matter what and its perfect, not discolored or melted at all.
...is your maf clean....
.
I have one wire that is literally 3-4mm away from one of my pipes, but I know it cannot ever touch it no matter what and its perfect, not discolored or melted at all.
...is your maf clean....
.
My car doesn't have a MAF, its SD tuned in 93'.
10-12-2009, 01:10 AM
#16
Also did you watch it running in the dark? If its arching you should see it in the dark. Have a buddy hold the pedal, or pull the throttle cable and try and look. You will hear/see it if it does.
replacing the plugs and wires will be fun lol.
Last edited by vff_jeff; 10-12-2009 at 01:22 AM.
10-12-2009, 01:33 AM
#17
TECH Junkie
iTrader: (10)
Join Date: Oct 2007
Location: Tucson AZ
Posts: 3,261
Likes: 0
Received 0 Likes
on
0 Posts
try replacing wire in question that is discolored. They arent a solid wire in there, its like a graphite powder and its relatively easy for that stuff to get broken up in there even if the wire isnt visibly cut open or whatever. See if that helps, covering a problem doesnt help it
10-12-2009, 09:43 AM
#18
TECH Enthusiast
iTrader: (5)
Join Date: Jun 2009
Location: McKinney, Tx
Posts: 732
Likes: 0
Received 0 Likes
on
0 Posts
I just changed the angle on the boot and zip tied it loosely away from the header, problem solved.
BTW, mine wasn't touching either, it was slightly gray on the wire from how close it was, lucky it didn't burn through lol.
10-13-2009, 12:25 PM
#19
On The Tree
iTrader: (3)
Join Date: Aug 2006
Location: Palm Beach, FL
Posts: 155
Likes: 0
Received 0 Likes
on
0 Posts
it could be your block off plates from your EGR or AIR. If they weren't sealed properly, it would sounds like a sowing machine. Mine does that, makes it sound like a bent pushrod when accelerating but stops when I'm cruising.
