Need help!! Almost tried everything!!!

[phen0m]

Hi all. I'm going crazy with this issue I've been having with my 2001 mustang gt and could really use advice. While driving in lower rpm 1000-2500 and in all gears except 1st, there is a small bucking/chugging while driving. It's not very noticeable by the passenger in the car but its there. It's really noticeable while driving up hills in lower rpm. If you give it a good amount of throttle or wot its not there, only when easy on the gas. Its been this way since I bought the car used, and I've been working to fix it ever since (1 year plus) below is a list of things I have changed in hoping to fix the problem.

-8 new c.o.p.
-new spark plugs
-new fprs
-new 02 sensors
-new egr gasket
-new tps
-cleaned MAF (also swapped with another car to test with no luck)

The mods on the car

-aftermarket throttlebody
-trick flow plenum
-jlt rai
-bbk catted X
-flowmaster catback
-SCT tuned on dyno

There may have been some other stuff but I can't remember. I've been looking for threads on this issue and am coming up dry. I really appreciate any help you guys can give. Thanks. :shrug:

 

[CobraBob]

Have you owned Mustangs prior to this one? You said you've noticed this chugging since you first bought the car (used). So I'm wondering if it is a non-issue, especially if passengers don't notice it. Sometimes our minds can make a relatively minor thing become a major thing. And the longer we sense it the bigger it becomes to us.

You checked all of the right things but you might want to data-log with a wide-band and maybe something will show up. That would be my recommendation.

 

[phen0m]

Thanks for the reply cobrabob. I own a cobra too and can feel somethings up with the gt. I don't know how to go about data-logging though.

 

[bs46488]

I have some of the same noises/issues. One suggestion I got was u-joints. I haven't replaced mine, so I don't know how valid of a suggestion it was. Thought I'd throw it out there.

Good luck. Keep us posted

 

[94-427]

I would be looking for a small Vacuum leak useally at PCV lines [moled from ford], elbos get soft and colapce and suck in

 

[bs46488]

Not to hyjack this, but what is the best way to look for a vacuum leak?

 

[phen0m]

I would be looking for a small Vacuum leak useally at PCV lines [moled from ford], elbos get soft and colapce and suck in

Thanks for the reply. I actually replaced all the pcv lines so I know thats not the issue. The car drives great, gets great gas mileage, plenty of power...do you guys think it might be injector related?

 

[DaBigBone]

I had the same issue twice.

First time, it was my PCV Line
Second time, my Air intake tube was cracked pretty bad on the bottom.

 

[Sheriff41]

Sounds like a problem I had with my car--turned out to be dirty MAF sensors. Cleaned 'em up and its run great since.

 

[Hissss5]

It could be your throttle position sensor. Its a black sensor on the side of the throttlebody.It has one plug plugged into it that has 3 pins in it.

 

[02steedakbgt]

I had that same problem and it was the EGR valve. Also check the vacuum lines going to and from the egr "or any vacuum lines at that". Hope this helps

 

[phen0m]

WIN! I swapped the fuel injectors and it cured the problem. I hope this helps save somebody a lot of effort and headache...

*update*
EGR was acting up too. Was more the EGR than anything else. I bought a block plate and sct tuned it out. Easy fix.