To All Terminator Junkies please help !!!

[2003 SVT ROUSH]

Ok i have a big problem with my cobra right now if anybody could help me or has experienced simllar please dont hesitate to input.

So once apon my last tune i made the power that is in the third bullet in my sig and have been verry happy with it ( note the A/F was 11.7 across.. So as of about two weeks ago my car started to spuraticly missfire ... at idle you can hear a dead hole here and there .. then if i give it a lil gas and hold at 1500 to 2200 rpm the car has a funky pattern of misses .. and the car shakes ... its a crappy sputter .. if i drive the car and im just cruising i can feel llittle pulses of dead spots and you can hear the thing missing in various patterns .. so i hit the dyno with it and this time around it was leaning 13.2 ish so instatly got out if it .. my tuner put more fuel in it and managed to get the a/f around 11.8 and the car made dog %&^t power 391 rwhp 399 rwtq !! that close to a 90 rwtq loss and 50-60 rwhp loss .. so i changed the plugs .. we tried again same thing .. same Correction factors /dyno .. even my IAT's were 30 degrees cooler this time due to my new H/E and dual spal fans .... the car runs like poo .

so heres what iv done to trouble shoot so far.

Did a compression text .. perfect across the board every cylinder the same . number 8 was just a couple psi higher ... this motor is only 6k old and built stout .. checked the coil packs .. all of them spark .. i even grabbed the coild out of my friends terminator and put em in mine and still ran like poo .. Hooked a smoker up to it and smoked the crap out of the thing and i have no vaccum leaks what so ever. ... changed plugs again .. no check engine light ... put a modis on it and it didnt give any codes ...
Hooked a fuel pressure gauge up to it and it only reads 27 28 psi at idle ... but the funny thing is the FRPS reads 39 40 psi according to the modis ... iv tried two really nice compression gauges to make sure it wasnt the gauges ans same thing .. so i didnt think that sounded right .. fuel filter checked good... so now im down to possibly faulty fuel pump ??... but why does the computer think the pressure is normal but the gauge reads low....?
and the other thing that has not been checked into yet is fuel injectors maybe a clog in or miss fire ... does anybody have any suggestions or ideas or simillar things in the past???? if any body could help me with this problem that would be great.

thank you for reading

 

[2003 SVT ROUSH]

Oh ad i even put a new Fuel rail pressure sensor on to make sure that thing wasnt crappin out and same thing

 

[BoostFiend]

Man I wish I could help, sounds like quite the dilemma. I would get the injectors flow tested.

 

[T-Pain808]

Damn dude sounds like you check it pretty good, I would have to take it to a proffesional, and just pay somebody already. I know it easy to do, but have them check it out.

 

[2003 SVT ROUSH]

Man I wish I could help, sounds like quite the dilemma. I would get the injectors flow tested.

Call me a doof but how would i get the injectors flow tested?? do sertain shops have a machine to do that ? ... so i just hooked up the Fuel pressure gauge to my buddys cobra that runs good and his read the same fuel pressure ... so i guess the damn FRPS reads about 10 psi higher on these things ..two gauges ...same deal . so it looks like i have narrowed the problem down to the injectors .. i have heard things about injector problems before .. its not crayz often but it does happen i just hope i can figure it out ..
Iv tried to spend as little as possible on the diagnosis but it looks like im gunna have to dish out regaurdless

 

[gray03beast]

if you have a fenderwell cold air check the maf meter for dirt and trash this could be giveing you the lean a/f you saw

 

[99riocobra]

28psi is the normal rail pressure at idle, just so you know.

 

[2003 SVT ROUSH]

Yeah ifigure the fuel pressure is good considering iv tried it on 3 cars now and all the same ... it has to be injectors at this point .

I dont have a in fender intake

 

[HEMIHUNTER]

I would check the injectors too. Maybe your tuner can do it/suggest a shop.
How about the fuel filter? [ start cheap ]
Hows your battery, could a bad battery effect your injectors? [ not enough spark? ]
Are they stock injectors?
Just thinkin' out loud. Good luck.

 

[03dsgcobranc]

i would pm or call a reputable tuner and ask them what they thought

 

[BoostFiend]

Call me a doof but how would i get the injectors flow tested?? do sertain shops have a machine to do that ? ... so i just hooked up the Fuel pressure gauge to my buddys cobra that runs good and his read the same fuel pressure ... so i guess the damn FRPS reads about 10 psi higher on these things ..two gauges ...same deal . so it looks like i have narrowed the problem down to the injectors .. i have heard things about injector problems before .. its not crayz often but it does happen i just hope i can figure it out ..
Iv tried to spend as little as possible on the diagnosis but it looks like im gunna have to dish out regaurdless

I know Stiegemier does flow testing and flow matching. You could also just find somone with some good injectors, swap them out and see if that helps.

 

[2003 SVT ROUSH]

I would check the injectors too. Maybe your tuner can do it/suggest a shop.
How about the fuel filter? [ start cheap ]
Hows your battery, could a bad battery effect your injectors? [ not enough spark? ]
Are they stock injectors?
Just thinkin' out loud. Good luck.

The fuel filter i checked and blew into it both ways and is good .. just changed it about a month and a half ago.. but i suppose ill change it again anyways . The battery is a brand new Optima red top, and yes stock injectors

 

[2003 SVT ROUSH]

im deffinetly going to look into injector flow testing and cleaning, im going to try to talk my friend into letting me use his injectors on his cobra in the mean time

 

[2003 SVT ROUSH]

im financially in a hole right now hah this is driving me nuts .. iv treated this thing like a saint .. has a new stout short block a brand new $ 8500 paint job i maintnance it with a magnafying glass and she is giving me this so far phantom problem !! it makes me want to sell it .. hopefully this injector thing is it .. im well over 20k deep into this thing i dont care if its rare im just stressin ... hopefully she runs good and changes my mind

 

[Snakebite2k3]

$8500 paintjob? lets see some pix of this beast

 

[2003 SVT ROUSH]

Yeah it was expendy , its still redfire , its just alot better of quality the the ford paint and better clear coat , i have to leave for work but ill see if i can get some pics up when i get home

 

[Juruense]

Well, since you say you are short on cash...

Cleaning the MAF and resetting the PCM does not cost anything.

You never know, it might help...

 

[Roushman]

Had same problem. Changed plugs cleaned MAF sensor and it went away. That was around right after I got the car and did some modding. Also maybe you got some bad gas.

 

[HISSMAN]

Dude? $8500 for a paint job? Who did you piss off? Mine looks like a mirror and lays as flat as if it was a solid sheet of Torch Red metal, and not paint. I could have had my car painted almost three times for that. And they did tear the whole car apart and do a full repaint followed by wet sanding and all of the other show car finish particulars. They did give me a great deal, and I didn't have to pay very much for the materials and labor, but even if you add the discounted cost I am still about half of what you paid. They used Standox Automotive finish paint. Very good stuff.

On the original note, it sounds to me like an injector the more I think about it. Pull them, send them off and be sure. Also, try what kilgore suggested.

-Jeff

 

[2003 SVT ROUSH]

The paint job is what i myself paid minimally for . , a few months ago i had a truck on the freeway have some sand /small gravel freckle a bunch of nicks in my paint and windshelf so i called my insurance company and i picked the shop of my choice and had had to pay a deductable of course .. it ran me 1000 bucks and there was over 9 k worth of crap , a brand new windsheld new head lights and fog lamps and a complete paint job from scratch .. every couple of days i went and watched the progress it sure looks like a new car now not a micro scratch on it ,

I cleaned the MAF a few months ago but i will be sure to do that again .. and when you say reflashig my pcm ... do you mean just disconnecting my battery ?? and then reflashing my tune ??