anyone have an idea as to what is wrong with my 5.0

[95.0mark]

Hi, i have a 95 stock gt and from the day i got it, when i accelarate moderatly to hard, when i pass around 3,000 rpm it seems as if i hit a wall of hard wind and would take a looooong time to pull to 6k.

and when this happens, my check engine light gos on and only stays on for 10-20 seconds and gos back off.

as i said the car is 100% stock.
so, what could cause this....i have had the car for about 8 months, and it does it multiple times a day, but the c.e.l always gos back off?

so any suggestions would be great, thanks. mark

p.s this is my first post and im glad to be aboard, you guys all seem to know alot about mustangs, so i hope you can help with this one.

 

[JJ95GTID]

Well I would say it is most likely the O2 sensors causing an over rich condition. Do you notice that your car smells like it is running rich? Has anyone told you that you car smells rich that was following you? Are you getting bad gas milage? A 'yes' to any of these can point to the O2 sensors. OR, there is also the IAT (incoming air temp) sensor and the ECT (engine coolant temp) sensor that are used to determine Air/Fuel ratio. Those are inexpensive and easy to replace. Could be a malfunctioning MAF too. Do you have an automatic? If so it could be something to do with the tranny since it is partially controlled by the EEC. I am sure there is more just can't think of any right now. Good Luck!

 

[95.0mark]

to answer your questions..no its a 5spd, and it gets 20 mpg city/highway...and i never smell raw fuel.
any other ideas, ive been told i should clean my maf, so i will try that.

any other ideas would be great. thanks

 

[FastmanGT]

I don't think its an O2 sensor. My car ran fine for 4 days w/o O2 sensors waiting for my O2 Extenders.

Replace your fuel filter. Its cheap at any O'Reileys or Autozone and you can do it in less than 20 minutes in your driveway.

 

[95.0mark]

fastman, do you think the fuel filter would trip the check engine light? i dident think it could, but i could definatly be wrong?

 

[FastmanGT]

If its clogged up enough it could throw a CEL relating to a lean condition, yes. If you haven't replaced the fuel filter since you got your car, just do it. Like I said, its cheap insurance and you can rule out one more problem.

 

[95.0mark]

good idea i will change it. i am going to get the codes pulled also. any other ideas. thanks, mark

 

[mo_dingo]

The codes should tell you what's going on. Obviously the comp knows something is wrong. When you do, post back.

Here is a link to running the codes without a code scanner. Get your haynes manual, because there are specific steps you need to follow inbetween KOEO and KOER.

If the computer can't adapt to the lean/rich condition, it will set off a CEL. My guess is either one/both or your O2 sensors are bad, or your MAF. But lets see what the codes come up with.

Don't replace anything until you post back here with the pulled codes. Sometimes the codes can be deceiving.

For instance, if you get the codes 172 & 176 (O2 sensors indicate lean, both sides), your O2's are probably working just fine, and they are telling you something else is making the car run really lean (i.e. MAF, etc).

Quick question.....Does the car hit this "Wall" when the car is bone cold? Try it out if you haven't all ready. That will eliminate some variables out of the equation.
Scott
Scott

 

[HISSIN50]

if im not mistaken, input from the lambdas is not used during WOT. you said that it happened when accelerating "from moderate to hard" so that could be a little test to help w/ diagnostics (like Scott suggested, little tests and CODES are paramount. i agree in full with his assessment, whatever my two cents are worth ).
it could be as simple as a dirty MAF wire (esp likely if you have a K & N and have oiled it lately - atleast on foxes it is).
good luck.

 

[BlackVert]

Subscribing because my car feels sluggish and I have been getting intermittent CE lights too after trying to accelerate hard (but not WOT).

FWIW, I just installed brand new O2 sensors because I got a TwEECer and I wanted to be sure I was getting good, consistant readings. So I doubt is it bad O2 sensors. I haven't installed the TwEECer yet though.

 

[jmuva44]

If you get a CEL and your car runs sluggish, the only thing you should do is check the codes. Your car is trying to tell you what is wrong....you need to listen to it.

 

[95.0mark]

to answer your question modingo, it happens cold and hot...makes no difference.
i usually try to not get on it to hard when cold, but its anytime.

and for your question hissin50, no it has the stock airfilter,which i replaced about 2 mo ago. any other ideas, i will hopefully pull the codes on wedsday.