slowcobra24

I just got an 03 Cobra with high mileage. Anyway, it's got aftermarket exhaust(high flow cats with xpipe and mufflers), CAI, and quick shifter.

I'm having a few problems. The first is a slight stumble/miss when under load. Regular driving I have no problems, but start pushing down the pedal, and it starts sputtering(especially above 3k rpm)...I believe it is either the MAF or the fuel pressure sensor. I cleaned the MAF and no difference.

Another is, does anyone have any pictures of the factory pvc lines routing? The p/o cut the two lines and has them just tied off and leaking oil from under the motor.(guess there are two of them as there are two lines, one from each valve cover) Where are these supposed to go? Also, after a hard run, it noticed quite a bit of smoke coming out of these. Is this normal?

Another noob question, the clutch is way at the bottom and he said it was only about a year old with less than 20k miles...It is moderately hard to shift, and start from a standstill. Plus, when I go WOT from 1st through 4th gear, it's like it doesn't want to do it. It pulls fine through first, push in clutch, shift, let out, hit gas. Nothing for a split second, then it grabs and jerks you back. Should it do this? If I slow down the shifting alot and ease through the gears while accelerating, it does fine, but I like to shift quickly as not to waste time/speed lol...

thanks in advance and sorry for the noob questions...I have tried searching/looking at pictures for 2 days and can't figure it out.

5.0 85 GT

dude, sounds likee the car needs a few things...no biggie, well with the pvc...was the car ever boosted big time? like diff blower on it or turbo and he converted back to stock? how many miles, and the clutch needs to be adjusted....if not you need a new one, it shouldnt do that....and he car could have a mis fire..if not try that fuel pressure reg sensor...i would change the plugs on the car...etc..do fluid flush on it....uhh but try to get the clutch adjusted, but if it grabs at the bottom you should be ok, but if it grabs up top shes on her way out....hope that helps...good luck..also the car should no tbe blowing coal out the back....my 97 did it when i had a small oil leak so those lines are pushing oil out then...keep an eye on your oil

slowcobra24

Got two of my problems fixed: I ran the pcv lines into the intake, and adjusted the clutch. Lets out about a 1/3 of the way up, just the way I like it. And it shifts alot better too. Now onto my final issue.

I cleaned the MAF sensor and IAT(or IAC) sensor, and I still have the miss. Bought a fuel filter but didn't get it put on yet. Plugs are supposed to be newer. I am either going to replace the fuel rail pressure sensor or the maf, which one is my question? Is there any way to test these before i go out and make a purchase? I unplugged the MAF and road around with no difference in the miss. It almost feels like it's getting too rich and backfiring when pulling from about 3200rpm to 6000.

Also, when I shift on quick runs, it's almost like the thing just dies when I hit another gear, then comes back to life a split second later. Here's a rundown:

Run gear up to about 6000, push in clutch, shift gear, let out clutch, hit gas, nothing for split second. It's like I'm not pushing on the gas at all and it's all the way to the floor. Then all of a sudden it picks back up like it's supposed to until I shift to the next gear and it starts over. If I get in it, and don't shift quick and don't stomp the gas when I dump the clutch(just ease in on the gas) it does okay...I'm stumped on that one...could this be the MAF or a different sensor? Thanks again!!!

5.0 85 GT

i do not think it is your maf....i owuld change your plugs, wires and coil packs....the plugs may be newer, but it may have a slight misfire.....i also would check your alternator...my buddies car ran like **** and his alternator was the cause...and mine just did the same...i would change t esp. with hi miles....

NotStok

+1 on checking the plugs regardless. When I changed my plugs for my pulley swap and tune, I ran a set of Autolite 103's, and the car ran like absolute crap between 1500 and 2000 rpm, stumbling and sputtering. I swapped in a set of NGK TR6's and it's been running like a champ ever since.

Definitely check your alternator as well. Mine just left took a crap on me, and I'm only at 52k. They're notorious for going out on these cars, and they ain't cheap.