Running Weird

[fiveliterstang]

Hi, I have a 95 GT 5.0. I have been having an odd problem with the car for little a while. The car has a rough iddle and when I and cruising along in any gear it pulses/surges (feels like some one was gently tapping the gas peddle.) The car also feels like it is down on power a bit. Then once in a while I will start the car and drive it down the street and it will all of a sudden just smooth out and run perfect like she use to (This doesn't last long usually a few min.). So far I have checked the plugs, they are fine. I have checked the fuel preasure at WOT and Iddle, thats normal. I have also changed the MAF, IAT and TPS sensors. Anyone have any ideas on what could be wrong?

 

[haulbalz]

Ttt

 

[Chythar]

Try checking for vacuum leaks. Perhaps a hose has cracked and is letting in unmetered air.

 

[95CobraMike]

yeah sounds like a vacuum leak, try looking at the PCV valve see if it popped out...or needs replaced
how many miles on the car?

 

[HISSIN50]

also check out the TPS for a bad spot along the range of its travel.

good luck.

 

[rude_life]

Make sure the Intake Manifold bolts are tightened down good. Also check the 02 Sensors and the Air Charge Temperature Sensor.. Just pull The ACT off and clean it, probably would help a little, maybe not be a smoking gun though

 

[fiveliterstang]

yeah sounds like a vacuum leak, try looking at the PCV valve see if it popped out...or needs replaced
how many miles on the car?

160k about, I don't think the PCV was ever changed by the previous owner, do you guys think that could be a possible smoking gun? As for the 02 sensors and the Air Charge Temp Sensor, I have already changed those and they made little to no difference. Are there any particular vacume lines that are prone to cracking on our motors or should I just run a general vacume leak test?

 

[CManT1914]

Might wanna pull the codes too. Autozone is supposed to do it for free, unless you get a jerk salesman (like I did), in which case order your own scanner for $35 from midwayautosupply.

 

[stangtoy1176]

Hey I'm having that exact problem you are describing. But I can pinpoint mine to the number two cylinder. Is yours accompanied by an exaust leak sound. Mine is, I can rev it up and you dont really notice it, but driving it feels like I'm about to run out of gas. I checked Mine by removing then replacing the spark plug wires one at a time to see if the stumble went away. I also did the same thing with the plugs on the fuel injectors...before I get replies saying I have a vacuum leak, I don't, I hooked it up to a smoker machine. Before you drain your bank account get a compression test and ar leakdown test, I guess thats my next step