Why is My Car Slow??

[rude_life]

Why is My Car SOOOOOOO Slow??

I have a stock 95 GT Vert. with 145,000..basicly stock, K&N Filter and Flowmaster Mufflers. I dont understand what the problem is..My car just doesent have any power..I have changed the spark plugs,Cleaned the MAF,Cleaned the K&N Air filter,New plug wires,New PVC...The best way i can describe it is it just feels like its being starved of something...When i stomp on it WOT,It just doesent go anywhere..But if i go about 5%-10% throttle and hold it there all the way up to almost redline, it runs a lot smoother..Its like it cant handle WOT. Its like it can only let a little bit of fuel (or air) in but full throttle just makes it lag and run like crap. What does this sound like guys? I was thinking fuel filter or pump. What are the symptoms of a faulty fuel pump or filter? MAybe my injectors are clogged?? Please Help

 

[Venom351R]

I have a stock 95 GT Vert. with 145,000..basicly stock, K&N Filter and Flowmaster Mufflers.

Theres your answer.

 

[final5-0]

If the fuel filter has never been changed with that many miles if just might be time to replace it.

A clogged filter can make it very slow to build rpm's even if you got the skinny pedal all the way down.

Later
Grady

 

[Venom351R]

wouldent doubt it if the 02's were shot as well.

 

[DFG 5OH]

change the fuel filter, and O2's, see how it is then. Run the codes too.

 

[ALMOSTFINISHED]

Sounds like the cats are clogged and blocking the exhaust from exiting. Full throttle has to breath ALOT. If you gradually hit the throttle and it accelerates then the exhaust can exit because its not all getting "pushed" out at once, if that makes sense. Like blowing thru a straw, if you blow real hard it has restriciton, blow at a lesser rate and its easier. Sounds like the brick inside the cat has gone solid.

Nick

 

[final5-0]

Sounds like the cats are clogged and blocking the exhaust from exiting. Full throttle has to breath ALOT. If you gradually hit the throttle and it accelerates then the exhaust can exit because its not all getting "pushed" out at once, if that makes sense. Like blowing thru a straw, if you blow real hard it has restriciton, blow at a lesser rate and its easier. Sounds like the brick inside the cat has gone solid.

Nick

Nick has a very good point as I've seen the thing you talk about happen with clogged cats. Time for a upgraded mid pipe anyway ............

On the O2's you need to know they are kinda pricey, lol. Another thing about the O2's is they drop out of play when the hammer is down so you may want to hold off a bit on them for replacement.

Later
Grady

 

[rude_life]

O2 sensors very rarely go bad without throwing a code..No check engine light guys.Ever. I used to get them all the time before i cleaned the MAF about a month ago and i had the codes read but it kept saying my 02 sensors were bad. But i cleaned the MAF and immediately the car ran 100% better. No Check engine light since. But now it just runs crappy. New BBK Full Length Headers and off road H-Pipe are on their way from UPS. Should be here any day now..and yes i bought the 02 harness extensions.

Nick you had a very good point on the cat's but wouldnt the same theory apply to a faulty fuel filter?

 

[mootang]

get a new cap and rotor/$20, fuel filter $15, plugs and wires, and see what happens. if you still have the problem then we can go from there.

 

[rude_life]

I have new FRPP 9mm wires and new Autolite plugs. Cap and rotor arent new but they dont look very worn. I will get the new Fuel Filter though my friends. Thank you Mootang, and everybody else. You guys are always very helpful indeed.

 

[mootang]

if you continue to have the problems after the new filter check your fuel pressure and if you can do a compression test. if you don't find any problems with the tests then put your new exhaust on and see if it was the cats.

also check your timing.

 

[rude_life]

Where can i get a compression test done sir?

 

[sociopath5.0]

Yeah man. Good luck. I would check the fuel filter, and install the new exhuast pieces and see how she runs.

 

[mootang]

don't know if anyone rents them or not. but you can get one for about $30. as for the fuel pressure gauge you can get one to mount on your fuel rail. that way you always know what your fuel pressure is. it costs about 50 bucks and goes in place of your shrader valve. just make sure to use thread sealer because you don't want to leak fuel and cause a fire.

 

[mootang]

not the best picture but it is right at the top left of the distributer.

 

[mustang479]

If your mustang seems to be running slower, then try to
remember when it started to run slower. What did you do to the car since you noticed it being slower :recent tune up,accident,noise coming from cats, engine mods. If you cant remember, then where in the rpm range is it weak?Sometimes the spout connector gets loose in Mustangs and then the timing cannot be adjusted by the computer as RPM's increase resulting in a very hard climb to high RPM range.

 

[rude_life]

Spout connector? never heard of it. What the heck is that and where is it located?

 

[Stanger007]

Spout connector? never heard of it. What the heck is that and where is it located?

The spout connector is on the passenger side of the car behind the airfilter. It's a little grey square about half and inch by half an inch. It is just a jumper (two metal prongs that make a circut).

When you pull it out and then start the car, the computer no longer adds timing ontop of the base setting which is 8-10* (stock). Most people with the stock heads go to 14* and if you have aluminum heads you can go even higher 16*+. Note that with increased timing comes the need for slower burning fuel (read: premium).

 

[5.0nmalecek]

Thats what happened to mine when i first bought it, the spout connecter was all jacked up so it was slower than shi*T. I cleaned the spout connecter up and fixed it and my mustang ran 85% better. It's still pretty slow because the fuel pump is on its way out, thats where the other 15% is. But ya if the spout circuit is open the computer is not compensating for the increase in engine rpms by advancing the spark. So the spark is igniting the fuel when the piston is already on it's way down on the power stroke. Pull codes by doing the KOEO and KOER test even if you don't have a check engine light. Mine came up with code 18 which is SPOUT circuit failure.

 

[rude_life]

OK well now im wondering about this spout connector..Where is it exactly and what does it look like? What exactly about it gets screwed up and what can i do to make it better?