Car doenst want to run right!

[sade04]

Ok guys ive had these little problems now for a little while now and havent had any time to seriously address them.

1. Most of the winter/now it "feels" like the car is down on power. Its really hard to describe but its almost like the car is only running on 7cylinders. During acceleration it feels really "airy" and weak. The exhaust doesnt even sound the same...just alot more hollow and not deep like usual. And the engine doesnt run as smooth. During the winter on really cold days the car would feel really really "brittle".

BUT ive noticed that when the weather gets nice (like last wed when it was 70) the car feels GREAT. VERY smooth, acceleration nice and torquey, and the exhaust was very deep.

2. Starting the car up the car makes Loud hissing noises like air escaping, or somehting. In feb when the temps were in single digits, in the mornigs there would also be a whining noise with the hissing. A vacuum leak? but would that cause intermittent driveability problems?

3. The car also seems to idle like it has a cam. I mean just the sound, the rpms stay dead steady, i think i remember thathas something to do with the egr?


(i had a ticking noise coming from my passenger side a little while ago and i was poking around to see if any of the header bolts were loose but it turned out that a spark plug was loose!! I pulled the plug and it looked a little white so i put in an autolite. so basically ive got 7fms plugs and 1 autolite. But suprisingly that didnt make a real difference. the car still has Good and Bad days)


Im sorry about the long post but if any of you guys have had these problems let me know! Thanks!

 

[OrangeMustangGt]

sounds like vac leak.

take a peice of hose, put it to your ear with the car running and scan some likely locations

 

[95BlueStallion]

Yeah, Ive thought the exact same thing with my car lately... I cant get the tires to break loose even... I used to hit the throttle and they would light up. I just bought new autolite plugs and fms 9 mm wires. Im going to put them on tomorrow, so Ill keep you posted if that helps. Otherwise I searched on here and found others saying EGR clogs at whatnot tend to create these symptoms. My clutch is worn out too, but I dont know how much that would affect acceleration once its fully released... If I find a cure for mine, Ill let you know what it was!

 

[greenstang1313]

sade04, its scaring me how similar your problems are to mine. Pretty much everything you described is extremely similar to the problems ive been having recently. Like the 'hissing sound' at startup like air is leaking, and the car feeling 'airy', quiter, and weak under accelleration.

I can tell you what I've done to try and fix this so you know what most like will NOT fix the problem.

-spark plugs
-spark plug wires
-new o2 sensors
-new fuel filter
-a bottle of seafoam
-a bottle of general fuel system cleaner
-a bottle of fuel injector cleaner

If anyone else is reading this thread and has other suggestions I'd like to hear them as well.

 

[sade04]

wow im glad that you guys understand the symptoms im describing

95bluestallion, I was tryin to do a search for the EGR but 3letter words dont work so if anyone has any suggestions. Im still on my stock clutch (113,000 miles), it doesnt slip or anything, its just very stiff. I dont know if that has anything to do with the engine feeling rough in general.

greenstang1313, ive done everything youve listed within the last year or so except for the oxygensensors.

^^also, do you guys have a problem shifting smoothly ? For me when the cars being ****ty, 1st to 2nd shift ALWAYS sucks, kinda jerky, as if i just started driving a 5spd. 2nd-3rd, still not smooth.

but when the car is being good, the shifts are as smooth as butter.

does this point to anything?



The biggest thing for me is that the driveability problems are intermittent. Like sometimes itll drive AWESOME, like everyhitng is just perfect. Then other times everything sucks.

 

[95BlueStallion]

I found the EGR issue came up when my check engine light started coming on and turning off irregularly. I did a search on CEL and found people saying that loss of power symptoms came from clogged EGR vacuum lines. So Im going to change my plugs, plug wires, clean my EGR system to the best of my abilities, and clean my throttle body for giggles... Well see, hopefully I have better luck than greenstang1313 did.

 

[HISSIN50]

You can pull the EGR and clean it (I use carb cleaner and a bore brush) - it takes 5 mins top to bottom to R/R and clean it. You can also do quick EGR diagnostics. You should note the EGR valve being closed at idle. If you connect spare vac hose to it, lightly suck on the hose (to simulate ~ 5" of vac). As the EGR starts to open, the car should start to shake and want to stall.

You can also wait disconnect the EGR vac line to the EGR valve. Drive the car (semi-gingerly since you might get some detonation if the computer hasnt realized there is an EGR issue and shut off the EGR function). See if the issue went away. If it did, I'd want to check for a leaking EVR.

All of that stuff should take about 20 mins to do (a test drive around your block would be all that's needed with the EGR vac line disconnected).

Also, if it idles crappy, run a cylinder balance test. It will pick up even minute misses as long as they are relegated to a cylinder systematically (not a random miss). The computer watches RPM drop and is much more specific than we (humans) are.

I will also say that I liked Kyle's opening remark about a vac leak. On a stockish cam, you should see about 20" hg at idle.

Good luck.

 

[95BlueStallion]

I lucked out. I changed my plugs, put on my 9mm plug wires, and sprayed out my throttle body with T/B cleaner. Shes running great! Idle is smoother, revs faster and smooth in neutral, and definitely feels more responsive! Also might help that I quit running 89 fuel with ethanol and changed to 93 octane.

 

[sade04]

Hissin, im definately going to try that out..thanks!!

bluestallion, ive actually never cleaned my t/b... ill be doing that in addition to the egr stuff.

Thanks guys

 

[95BlueStallion]

I spoke too soon! The car does get around town smoother, but out on the lonely blacktops of rural Iowa, Im still having problems! I decided the other day I wanted to see where my car would top out with the 3.73s... My stock '96 GT did 145mph for me, so I figured my car would do the same unless the gears limited it. But when I hit 120mph the car started making popping sounds out of the exhaust and wouldnt climb any further! I was only running 3500 rpms or so, its not like I was red-lining it! What would cause my car to start missing at high rpms? Lean fuel mixture? Bad timing? Please throw out some ideas!