95' Cobra SVT Problems

[xspektrex]

just paid 7g's for 95' Cobra SVT (240hp V8) with 114,000 miles:

Known Problems:

- Really hard/irregular idle even for a CAM change
- Fuel/Air gauge on dash is reading lean when:
--> during idle and acceleration
- Fuel/Air gauge on dash is reading rich when:
--> during driving when coasting (no gas pedal contact)
- Smell of Gas constantly while driving
- Exhaust Leak on Passenger Side
- Bad vibration during 4000-5000rpm range (every gear)
- Popping sound (not trans mount) during some shifts
- Low Grade Alternator (Sound System Seems to be Maxing it)
- Low Grade Battery (Speed Star???) (who the hell does this?)
- AC clutch never engages but pulley on compress moving fine

Known Mods on Stang:

- MSD ignition
- N.O.S (not direct jet) - (currently not using)
- CAM of unknown manufacturer
- Headers and straight pipes
- Cold Air Induction (wheel well, not the fake shite)
--> Stock MAF ()
- High Performance Tranny (unknown manufacturer at this time)
- High Performance Clutch (unknown manufacture at this time)
- Possible High Performance Fuel Pump

Ready to get my baby in tiptop like she needs to be so any advice or known fixes would be great.

I know the MAF needs to be "Pro-M" for the CAI...it's in the mail!

Thanks,...

[1234]

One thing that will help is a tune. More specificly a dyno tune.

[Scut95]

if it has stock gears, i'd say go for a set of 3.73 or 4.10's

[xspektrex]

...that's not all that helpful plus i don't wanna spend money on a dyno right now. Dropped 2 paychecks on her and i'm broke so ineed some decent advice (mechanically) to get me on the right path...Ima hook her up to an ODB2 terminal today and get some error/fault codes flowing...

[1234]

When you get the codes post them and we should be able to help more. It tough diagnosing over the web.

[xspektrex]

went and borrowed and actron OBDII and the code reader error'd trying to comm. with the pcm/ecu/whatever they call it...hehe...so...

I figure there may be a software flash in it that locks out scanners etc...

[Benjytps]

fix the exhaust leak or you will never get an accurate afr reading especially if the leak is at the head. Do you have a wide band afr gaugeor a narrow band? Check all of the free items you can check ie.. plugs (including the gap)wires, cap ,rotor ,timing ,vacuum lines, fluids. Eliminate all of your free possibilites first then fix the known issues such as the ex leak. Your 3rd step will be a tune, either a mail order tune or a dyno tune would be a very good investment. Contact us at TPS Performance and we will build you a tune that will correct any afr and drivability issues you may have with the tuning.

[Scut95]

Quote: went and borrowed and actron OBDII and the code reader error'd trying to comm. with the pcm/ecu/whatever they call it...hehe...so... I figure there may be a software flash in it that locks out scanners etc...

95 is still OBD I so the scanner you plugged in won't work. I know the diagnostic ports are there for OBD II but ford was just getting ready for 96. You can get a code scanner for OBD I but you have to sit there and count the beeps and their length, then look them up in the book that comes with it.

[bbunt302]

You're best bet would be to take the AFR gauge and throw it in the trash. Judging by the other parts on the car, it is probably a cheap Autozone narrow band meter that will do you more good in a landfill than it will on the car. They are extremely inaccurate and are probably giving you false information about what the car is really doing.

For the other issues, start out fixing what you know is wrong: the exhaust leak. That, along with running rich, is probably where your smell of gas is coming from. Then if you haven't already done so, give the car a full tune-up with plugs, wires, distributor cap and rotor, fuel filter, a transmission flush, all the fun stuff.

Next, reset your base idle. Follow the procedures here: The Corral - 302/351 Idle Adjustment and Reset

Also, take a look at your fuel injectors and see what color the caps are. The 95 Cobra should have 24# injectors, which will have a blue top. 19# injectors are yellow and 30# injectors are red. You will have to ensure that you get the correct MAF to match your injector size. Also be aware that the Cobras have a different ECU than the GTs that are calibrated to work with the injectors. This means you need to ensure that the MAF you are buying will work correctly with not only the injectors, but also the Cobra ECU. You will probably need to do some more research to find exactly which MAF you need.

As for some of the other items, I'd also take the straight pipes off and place them right next to the AFR gauge in the dumpster. Then invest in either a catted or non-catted X or H pipe (lots of options here depending on personal preference). You will gain power and have a much better sound (IMO) than the straight pipes. If the "popping sound during shifts" is coming from the exhaust (which it very likely is with straight pipes), this will fix it.

As for the alternator, the stock alternator is a 3G 130 Amp alternator. You shouldn't be having any problems with it outputting enough juice. If so, you may have a wiring problem.

[xspektrex]

What a fun day...Throw out bearing is going bad now...so ima replace the throw-out-bearing, clutch plate, and flywhell all in one hit; roughly 700bux for premier shite but worth it in the long run. Changed out the IAT, for literally no change in running condition even though the IAT was burnt up due to a poor install on the CAI. Previous owner installed a CAI where it goes a lil sumtin like this:

wheel well -> MAF (80mm); MAF-> IAT (bevel from 70-80mm); IAT-> Throttle Body (80mm bevel to 70mm)

what where they thinking causing a trainwreck of air before,during,and after imp. sensors.....

Research has shown that even the "narrowband" FAR is good for sumthing so long as the 02 sensor it's hookd to isn't blown... (im sure it is at this point). Still however going to invest in a wideband digital FAR that also does a few other neat tricks.

As far as running lean im at a loss...I'm taking a shot in the dark and saying alot of that is coming from the incorrect MAF and B.S. CAI install.

As for the injectors, they are 24# and look to be in good shape considering the age of the car...(still going to buy new ones when I can).

Something has "got-to-give"!!! 50miles/quarter tank of gas is B.S.

Keep picking your brains gent's as I am a mustang noob (owned everything but, so I made the conversion back to American Muscle)

[Scut95]

Quote: Something has "got-to-give"!!! 50miles/quarter tank of gas is B.S.

I use a 1/4 of gas around 50 miles when im driving around town. I think that is about all you're going to get, haha.Highway is different though obviously

[xspektrex]

just did some "in-town" driving for 2-days and got 72 miles to 1/2 tank roughly...coming from 07' VW GTI MKV I think I just need to get use to 5.0L 240hp engine as opposed to the MKV's 2.0T w/200hp (turbo'd 4-cyl). It got about 200miles to 1/2 tank "in-town" and "highway" driving combined. Just hurts a lil with gas prices the way they are u know...She's so pretty and needs to be seen and heard!

[xspektrex]

For the RECORD...you guys rock! I know my baby needs some work and I might possibly become annoying within this forum with an over abundance of questions (pro from yesteryear turned noob). Just wanna let you stangers know I appreciate all the advice and thoughts given thus far. I'll need plenty more I'm sure...just bear with me; I'll get there. Just on what ya'll have told me so far and research regarding your thoughts I have learned and retained alot. I almost feel like tearing down the engine and puttin er' back together again just to kill time.

Again though, THANKS!!!
You Guys Rock!!!

[1234]

Thats not to bad i get 80 on half a tank city and highway combined. Now on highway alone i get 24 mpg.

[xspektrex]

Done alot of research on the narrow and wide band FAR's and compared what I see on mine to what others say they do. My "phantom" narrow-band seems to always run in the red "lean" when into the pedal be it hard or not. The only time it is running in the yellow "Stoich" is when coasting or sitting still at idle. I have yet to see it within the green "Rich" area. The gauge itself is digital and professionally installed but I'm trying to determine the source of the vehicle running lean. Now, based on mid-level mechanic knowledge I know the smell of gas would indicate a running "rich" condition and not "lean". Any ideas aside from the obvious like the fuel filter/fuel pump? Possibly an injector detinating early? Also the interior of the car is getting really hot. If the windows are up your sweating and the windows are fogging. Common with ponies or big arse engines?

Hit me with knowledge gents, hit me hard...

[xspektrex]

----------------------------------------------
KOEO (Key Off Engine Off) Code Scan Results
----------------------------------------------
- 111 -> System Pass. No problem found by computer during KOEO Self-Test.

---------------------------------------------------
CMC (Continuous Memory Codes) Code Scan Results
----------------------------------------------------
- 172 -> Heated Exhaust Gas Oxygen (HEGO) Sensor – voltage signal indicates running “lean” (Bank #1)

- 177 -> Heated Exhaust Gas Oxygen (HEGO) Sensor – voltage signal indicates running “rich” (Bank #2)

- 181 -> Heated Exhaust Gas Oxygen (HEGO) Sensor – voltage signal not switching: indicates “lean” during part throttle engine operation (Bank #1)

- 186 -> Injector pulse width lower than expected or Mass Air Flow (MAF) sensor signal is lower than expected

-189 -> Heated Exhaust Gas Oxygen (HEGO) Sensor – voltage signal not switching: indicates “lean” during part throttle engine operation (Bank #2)

-------------------------------------------------
KOER (Key On Engine Running) Code Scan Results
-------------------------------------------------
- 4 -> Indicates V8 Engine

- 314 -> Thermactor Air System inactive during Engine Run Self-Test (Bank #2 with dual oxygen sensors)



Seems like the issues are interrelated to the MAF and O2 sensors; if this is the case I'm smiling cause that's not so exspensive to fix. Your thoughts gents.

[PureVenom]

Sounds like you definitely want to swap out your O2's....once those codes go away, it would be interesting to see if the MAF code goes away since the computer will not be puking on itself with all the O2 codes. It very well could be just a secondary code being thrown because the computer is going nuts trying to figure out the O2 situation.