New mustang, few problems, please help!!!

slowcobra24 · Sep 14, 2009

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? The p/o cut the two lines and has them just tied off and leaking oil from under the motor. 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.

twogts4us · Sep 14, 2009

No offense, but why did you buy this car with all these issues? A dream car can turn into a nightmare very quickly.
Did you clean the MAF with the proper spray chemical? Others can leave a residue that will wreak havoc on the MAF. I'd bet it's the fuel filter - a cheap and easy fix. Follow the instructions on this link for both cleaning the MAF and changing the fuel filter. Link is for a Bullitt Mustang, but it's all the same, and it's a great reference site. BULLITT Archive Mustang Maintenance
Regarding smoke, you should try to find where the smoke is coming from. If it's leaking oil, where is the oil coming from? If the PVC is "tied off" then it very well could be coming from there. Especially with a boosted motor, it needs to vent. On the pass side it SHOULD be connected to the intake tract.

The clutch, quite honestly, sounds like a shadetree mechanic installed it. You can somewhat adjust the friction point with an aftermarket quadrant and firewall adjuster. Do you know if it has these already? Ck under the dash (you really have to squeeze in there to see - take a flashlight) and look for an anodized aluminum gimmick like this - this is a quadrant.

The OEM one is plastic.

Under the hood, ck on the firewall and locate where the clutch cable comes out. It's on the drivers side. There are only two possibilities and its not the throttle cable. The clutch cable will wind down underneath the engine (obviously!). Does the firewall gimmick look like this? (If it's plastic it's OEM)

Let's start there and see if we can get you somewhere.
Congrats on the Cobra purchase. The Terminators are just awesome.

slowcobra24 · Sep 15, 2009

Thanks for the help. The guy was letting it go REALLY cheap because of the problems so I picked it up. Anyway, I do have an aftermarket quadrant. How is it adjusted on the cobras? I saw how to do it on the regular GT's, but I'm sure it's probably different. I am going to change the fuel filter and the fuel rail pressure sensor to see if it gets rid of the slight miss. It still runs decent and pulls hard, just like it's "burping" when going through the rpms lol.

The pcv valve line is about 4ft long and ziptied to the bottom of the motor, with a cut end letting oil and smoke come out of it. The "valve" on the driver side valve cover is the same way. Where does the one on the driver's side plug in on the intake? And the pcv valve should go in the air intake, correct? It has a Kenne Bell cai on it...

Thanks again!!!

Kilgore Trout · Sep 15, 2009

I would suggest taking it to a good stealership and having them go over the car. The clutch issue could be anything from out of adjustment to needing to redo a poor install. Cost will be between $0 and $1000 to correct.

The PCV system sounds like it is really messed up but it is common for fools to do this.

Have the car gone over by a good mechanic who knows Cobras.

Good luck, you are going to need it.

trombonedemon · Sep 15, 2009

How much gas is in the car when it starts to sputter. It could be the fuel pump. Put a full tank of gas in it. If it goes away its the fuel pump!

dustang50 · Sep 15, 2009

trombonedemon said:
How much gas is in the car when it starts to sputter. It could be the fuel pump. Put a full tank of gas in it. If it goes away its the fuel pump!

+1 on the fuel pump. Check out the old one & see what kind of stuff is in it. You may have a clogged injector, too.

wmburns · Sep 15, 2009

If the p/o cut and tied off the PCV line, is it possible the line is NOT air tight on the intake side? If so, unmetered air could be entering through the PVC line. This unmetered air will cause the mixture to be lean because the PCM can not accurately compute the fuel injector pulse.

Going out on a limb here. The P/O cut the PCV line because of excessive blow by. Likely that if the spark plugs are inspected, they will be fouled. Suggest checking the spark plugs.

If blow by is the root problem, a compression and leak down test may be in order.

Yes it is normal to get some blow-by after a hard run. However, for stock cars, the blow-by is not normally seen because it is vented back into the intake. It is not normal to have large amounts of raw oil pooled inside the intake. Obviously, there is enough blow-by oil for it to be visable. Many people will install an oil separator in the PCV line to keep the oil out of the intake. Steeda makes one that is popular.

GDawg · Sep 15, 2009

PVC I would check. New valve... $6. IAC may need to be cleaned. Plugs may be bad. Plug wires may be bad. Fuel filter should be replaced often (I replace mine once a year but it can go a bit longer).

BUT, something no one checks... Alternator AC ripple. My alternator would charge just fine. I had a "bucking" under WOT. I checked my alternator AC ripple with a DMM (Digital Multi-Meter) and it looked fine (.27 vac) but when I ran it through a "D-Tech" diagnostic machine, my alternator came up with .48 vac which it failed the test. .40 vac is acceptable but no more. AC ripple is dead diodes in your alternator and if there is too much it messes with your computers. I swapped out my alternator and retested. I got .03 vac which was well within spec and guess what? My "bucking" went away!

On Edit: Btw, I needed an oil separator and you can buy one from Home Depot or Lowes for ~$20 as opposed to huge amounts of money from Steeda. I made my own. See below...

fast97gt · Sep 15, 2009

might outa look at the TPS it can be bad especially with a hesitation.

slowcobra24 · Sep 15, 2009

Okay, so I have about $1000 worth of sensors/parts suggested to replace lol...Is there any way to check these things before I replace them? I got the pcv lines ran into the intake and my clutch adjusted.

I also just noticed the car doesn't seem to have the EGR on it. Basically everything on the driver side of the blower is gone, but the fuel rails...I'm not throwing any codes so I'm guessing there is a tune on the car.

Now onto my final issue.

I cleaned the MAF sensor and IAC, 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/or almost 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 punches back to life 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!!!

wmburns · Sep 15, 2009

IMO no one has suggest that you change any sensors. The suggestion was to check. Throwing parts at today's cars is usually a money loosing activity.

The fact of the matter is that each one of the items mentioned can cause problems. Sometimes you have to take the steps.

Have you been able to determine if the engine is allowing excessive oil in the blow-by during a hard run?

GDawg · Sep 15, 2009

KISS...

Keep it simple stupid...

This last week I had a guy tow in a truck cause he thought his starter was out so he bought a starter and it still didn't work. I showed him it was a bad cable. Now he owns two starters.

This last week I had a guy bring in a car with a bad alternator and then he replaced it and the new one didn't work either. It was a 175 amp maxi fuse at the fire wall NOT in the high amp box in the engine bay or in the IP fuse box in the cab. It was a $12 fuse. Now he owns two alternators.

Try the AC ripple test first... it's free if you have a digital multi-meter. With that same meter, do a free ohm test on your spark plug cables. Plugs are cheap and if they are old, you should replace them regardless. Oil separator... ok... pull your intake tube off and get a flashlight and look beyond your TB into your intake and see if you can see signs of excessive oil. That's free too.

Then get back to us.

slowcobra24 · Sep 15, 2009

Yes, there is more blowby after a hard run...that is how I noticed the pcv was not right. Smoke coming from under the front of the car. Looked and saw some oil hanging off a cut off line. It was a line running from the pcv valve. I don't believe the blowby is too excessive, but the undercarriage has some oil spread around on it. Stupid p/o... But all I did was connect both of the holes on the valve cover gaskets with a "T" and ran that into the intake. No more smoke, no more oil drips.

I really want to believe my problem is a sensor, but don't know how to check them. Do I need some kind of meter to run an ohm test or something on them? On other vehicles I've had, a certain sensor made certain things happen when it was going bad. I've replaced 2 MAF sensors on GM vehicles that were doing about the same thing, but they were throwing a code.

Would the EGR being deleted throw a code? If so, it has to have been tuned out or the bulb taken out of the actual light. Opinions on this? If it does turn out to have a tune and it's wrong, could it cause my symptoms? Anyway, thanks again for any advice!!!

twogts4us · Sep 15, 2009

slowcobra24 said:
On other vehicles I've had, a certain sensor made certain things happen when it was going bad. I've replaced 2 MAF sensors on GM vehicles that were doing about the same thing, but they were throwing a code.

Just because another car had a sensor go bad doesn't mean this one's issue is the same.
That said, I am interested in your comment about the MAF making no difference whether is was plugged in or not... Sounds like a bad MAF (or bad connectors?)

Do you have any pictures of the engine?

Kilgore Trout · Sep 16, 2009

If all the stuff is removed from the driver's side of the blower and the PCV and EGR systems have been messed with then I must assume the car is pretty highly modified.

Can you talk to the seller? He could provide the best guidance.

What are your plans for the car? Keep modding or return to stock? Did you realize what you were buying here?

GDawg · Sep 16, 2009

Where do you live? If in Colorado, I can help you do the tests.

slowcobra24 · Sep 16, 2009

Thanks so much but I'm in Alabama. I just found out it used to have a KB 2.2 on it...so it has been highly modded before. Didn't know that before I bought it. I didn't really plan on modding it anymore. It is already almost too fast for me. I just want to get the miss out of it. I am going to replace the fuel pump hopefully Friday(busy and just got the right tool lol). If that doesn't work, I'm going to go with the fuel rail pressure sensor since I have read it is a common issue that causes this kinda miss...$106.

CAN ANYONE TELL ME OR GIVE ME A LINK ON HOW TO CHECK THE OTHER SENSORS? Like the MAF, TPS, etc...

And the car didn't run any different at all when I unplugged the MAF. I did unplug it while the car was not running. Then crunk it up and took off. Didn't throw a code either...

Would the other 2.2 supercharger require a different MAF, or injectors, etc that if not changed when the supercharger was returned back to stock cause this problem? thanks

slowcobra24 · Sep 16, 2009

I have posted a picture below. The things with red on them I do not have. The ones with blue I do have. And the green arrow goes to a port on the side of that black thing. It was just open when I got the car. I put a vacuum plug on it. Where is it supposed to run to? I'm pretty sure it has something to do with the boost. My boost gauge doesn't work by the way. Also, I have a metal intercooler resevoir...

I don't know if you can tell by this picture, but this is all I have on the drivers side of the supercharger: that black thing that's missing that line(I'm pointing at), and the fuel rail...that's it. Pic:

slowcobra24 · Sep 16, 2009

Also, could the egr not being there cause my problems? No egr means it would change the a/f ratio if the stock tune has been installed, but wouldn't a service engine light come up? Just venting ideas here. Thanks again for the help. I know it's not anything mechanical causing the miss because it runs good and the supercharger pulls good, just that "burp." I think it's a sensor or the fuel filter...I'm also going to get out there one night and see if I can see anything arcing when I rev it up(plugs, etc...)

New mustang, few problems, please help!!!

slowcobra24

New Member

twogts4us

slowcobra24

New Member

Kilgore Trout

Fried or Broiled ?

trombonedemon

Well-Known Member

dustang50

Member

wmburns

GDawg

fast97gt

Active Member

slowcobra24

New Member

wmburns

GDawg

slowcobra24

New Member

twogts4us

Kilgore Trout

Fried or Broiled ?

GDawg

slowcobra24

New Member

slowcobra24

New Member

slowcobra24

New Member

Similar threads

New mustang, few problems, please help!!!

New Member

New Member

Fried or Broiled ?

Well-Known Member

Member

Active Member

New Member

New Member

Fried or Broiled ?

New Member

New Member

New Member

Similar threads

Privacy & Transparency

Privacy & Transparency