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98 Mustang GT...Running rough, tailpipes black with soot

  • Thread starter Thread starter sanitarium16
  • Start date Start date Jun 8, 2006
S

sanitarium16

New Member
Oct 17, 2004
15
0
0
Jun 8, 2006
#1
  • Jun 8, 2006
  • #1
My car was perfect up until a few weeks ago. My car is modified with the following: Mac CAI, FRPP 70mm Throttle Body, BBK Intake Plenum, FRPP PI Intake Manifold, Mac Off-road h-pipe,Flowmaster super 40 catback, Trans-go shift kit, Diablosport predator tuner premium fuel tune.
I have my rear o2 sensors shut off via the predator tuners so i am not throwing any codes or CEL. All 02 sensors were replaced with Bosch last year and the car has brand new plugs, wires, MAF sensor,IAC,cleaned the EGR Valve, cleaned throttle body and new fuel filter. Using the diagnostics feature of my diablo predator i am able to read multiple things. My tail pipes are black with soot and have always been since i put on the off road h pipe. My 02 sensor readings fluctuate from 0.1 to 0.7. I was told this is normal. My MAF voltage is .76 idle. My idle is jumpy....goes from 620,650,700 and fluxuates in between there. There is no pinging or detonating going on that i can hear and i fill up on 93. Do i have to buy a new h-pipe with high flow cats in order to fix this problem? Another note is that my spark advance is jumping around too. 17 to 18 to 19 at idle. I have it raised a little (8% throughout entire rpm range) but i have always had it on this setting. Another thing to mention.....there are no vaccum leaks...sorry for the long post but im trying to be as detailed as possible.
 

squares98

Member
Aug 20, 2004
852
0
17
Orange,ca
Jun 8, 2006
#2
  • Jun 8, 2006
  • #2
You will get that soot you are talking about with an off road h pipe.
Have you ever seen how it runs with the stock tune? Over Oiled Air Filter?
 
S

sanitarium16

New Member
Oct 17, 2004
15
0
0
Jun 8, 2006
#3
  • Jun 8, 2006
  • #3
It does it with the stock tune as well. It JUST started happening the tune wasnt changed at all.....air filter is a new AEM dryflow oil-less air filter.
 
R

RoadconeTuning

New Member
Apr 4, 2006
458
0
0
Upstate, SC
Jun 8, 2006
#4
  • Jun 8, 2006
  • #4
so the idle is fluctuating 80rpm.. thats not all that bad... and the soot is unburnd fuel that is normally caught and burned in the cats... if it pulls fine doesnt ping and gets ok gas mileage its fine....
 
S

sanitarium16

New Member
Oct 17, 2004
15
0
0
Jun 8, 2006
#5
  • Jun 8, 2006
  • #5
I can feel it through the steering wheel and that drives me nuts cause it never did it before. On an off releated topic, do you guys know anyone who does custom tuning for the diablosport preadtor?
 

squares98

Member
Aug 20, 2004
852
0
17
Orange,ca
Jun 8, 2006
#6
  • Jun 8, 2006
  • #6
any chipmaster revolution dealer.
 
R

RoadconeTuning

New Member
Apr 4, 2006
458
0
0
Upstate, SC
Jun 8, 2006
#7
  • Jun 8, 2006
  • #7
well what is it doing... you really havent said anything specific as to how its running rough...

have you changed the spark plugs? checked the wires? fuel filter?
 

Mike97gt

it doe snot
Founding Member
Jan 26, 1999
10,633
7
89
the people's republic of massachusetts
Jun 8, 2006
#8
  • Jun 8, 2006
  • #8
does it feel like it's misfiring, try going up a hill a low rpm's with the converter locked if your a auto. or in 4th gear under 2k if a stick. and see if it feels like it jerks or bucks at all.
 
S

sanitarium16

New Member
Oct 17, 2004
15
0
0
Jun 8, 2006
#9
  • Jun 8, 2006
  • #9
Yes, i have changed everything. spark plugs are brand new motorcraft, wires brand new frpp 9mm and new motorcraft fuel filter. Every matainence item is perfect i am tedious when it comes to that. It doesn't feel like a misfire and when i rev the engine it is perfect.....just idle....it is driving me nuts. It just started happening all of a sudden!
 

speedfreak98r

Banned
Jan 31, 2006
0
0
0
Houston Area
Jun 8, 2006
#10
  • Jun 8, 2006
  • #10
svttech76 said:
does it feel like it's misfiring, try going up a hill a low rpm's with the converter locked if your a auto. or in 4th gear under 2k if a stick. and see if it feels like it jerks or bucks at all.
Click to expand...
Mine does that..Whats myproblem?
 
S

sanitarium16

New Member
Oct 17, 2004
15
0
0
Jun 8, 2006
#11
  • Jun 8, 2006
  • #11
Tps is reading .097 volts.
Here are some other readings in the "gas fuel" selection. not sure what they all mean

31.84V CAS GRND
2.26V FLI V
2.7V FRP V
5.0V FTPV
3.6-3.7MS FUELPW1
3.6-3.7MS FUELPW2
2.69V IAT V
.94V EGR VALVE
2.32V EFTA
100% FP
 

DTNODYA

Member
Dec 15, 2005
831
1
16
Jun 9, 2006
#12
  • Jun 9, 2006
  • #12
PCV ???

Some crappy gas?

 

speedfreak98r

Banned
Jan 31, 2006
0
0
0
Houston Area
Jun 9, 2006
#13
  • Jun 9, 2006
  • #13
ttt
 
R

RoadconeTuning

New Member
Apr 4, 2006
458
0
0
Upstate, SC
Jun 9, 2006
#14
  • Jun 9, 2006
  • #14
if fp is for fuel pump duty then your dumping a LOT of fuel in at idle... our car uses the fuel pump to adjust flow instead of a regulator so thecontrol for the pump might be shot causing a lot of fuel to be dumped into teh engine and the car probably burns it just fine off of idle but it struggles at idle...

<---- took a wild guess.
 

speedfreak98r

Banned
Jan 31, 2006
0
0
0
Houston Area
Jun 9, 2006
#15
  • Jun 9, 2006
  • #15
TTT
 

1fast03pony

Member
Jul 1, 2003
749
0
17
New york
Jun 9, 2006
#16
  • Jun 9, 2006
  • #16
sanitarium16 said:
My car was perfect up until a few weeks ago. My car is modified with the following: Mac CAI, FRPP 70mm Throttle Body, BBK Intake Plenum, FRPP PI Intake Manifold, Mac Off-road h-pipe,Flowmaster super 40 catback, Trans-go shift kit, Diablosport predator tuner premium fuel tune.
I have my rear o2 sensors shut off via the predator tuners so i am not throwing any codes or CEL. All 02 sensors were replaced with Bosch last year and the car has brand new plugs, wires, MAF sensor,IAC,cleaned the EGR Valve, cleaned throttle body and new fuel filter. Using the diagnostics feature of my diablo predator i am able to read multiple things. My tail pipes are black with soot and have always been since i put on the off road h pipe. My 02 sensor readings fluctuate from 0.1 to 0.7. I was told this is normal. My MAF voltage is .76 idle. My idle is jumpy....goes from 620,650,700 and fluxuates in between there. There is no pinging or detonating going on that i can hear and i fill up on 93. Do i have to buy a new h-pipe with high flow cats in order to fix this problem? Another note is that my spark advance is jumping around too. 17 to 18 to 19 at idle. I have it raised a little (8% throughout entire rpm range) but i have always had it on this setting. Another thing to mention.....there are no vaccum leaks...sorry for the long post but im trying to be as detailed as possible.
Click to expand...



JP i thought you fixed this with the coil packs!
 
S

sanitarium16

New Member
Oct 17, 2004
15
0
0
Jun 9, 2006
#17
  • Jun 9, 2006
  • #17
i thought so too......new MSD replacement coil packs arrived today.....will give them a try.....maybe my stocks are messed up too.
 

1fast03pony

Member
Jul 1, 2003
749
0
17
New york
Jun 9, 2006
#18
  • Jun 9, 2006
  • #18
let me know if you need a hand puttin them in.. tomorrow im free as you know
 

four six

Member
Jan 19, 2006
506
2
18
Hobart, IN
Jun 9, 2006
#19
  • Jun 9, 2006
  • #19
MAF? My Exploder had a similar problem
 
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