Please help troubleshoot my problem.

[tanion]

I have a 2001 GT automatic with 47K miles. Only engine mods are a K&N intake kit and steeda underdrive pulleys which have been on for a long while. The problem is that the car often jolts while cruising along. It's most noticeable when trying to just maintain a low speed, holding it between 1000 and 1500 RPM. It's been doing this for quite some time. However, it seems to be getting progressively worse. I now can sometimes feel this jolting while accelerating although it's much less noticeable when I'm on the gas. The car is past due for a fuel filter replacement as prescribed by the recommended maintenance schedule. I plan to check the MAF to see if there is possible some oil from the K&N causing problems. Any suggestions will be greatly appreciated.

 

[ACSPONY]

I would bet it's the MAF. Especially at low speeds at the rpm you specified. When did you oil the K&N?

 

[Kilgore Trout]

Could be MAF. Could also be tranny related. Have you even changed the fluid and filter?

 

[tanion]

It's been about 3 or 4 months since I last cleaned and oiled the air filter. So checking the MAF will be my next option. When I first noticed this happening the first thing I did was have the tranny fluid changed since it was overdue anyway but that did not help. I've tried resetting the computer by disconnecting the battery for a few minutes but that did not help either. As I said earlier, the fuel filter is overdue to be changed but I don't know if that is the problem. The sensation when it happens is kind of hard to describe. Like brief pulses of hesitation, it's definitely become more noticeable over the past few weeks.

 

[Jackie Chan]

could be the ac kicking on and off

 

[MineralG2k2GT]

It very well could be the MAF..when i cleaned my K&N i used the recharger kit and definitly put to much oil on the filter..it got all over the MAF and my car ran like ass as a result. Once I took it off and cleaned it with some car cleaner it ran great again

 

[tanion]

could be the ac kicking on and off

No, it's definitely not the AC.

 

[Kilgore Trout]

If you cleaned the K&N 3-4 months ago it is defintely the MAF.

 

[ACSPONY]

Cleaning the MAF

 

[ACSPONY]

wtf, damn double posts...

 

[Kilgore Trout]

Step by step with pictures:
http://www.bullittarchive.com/html/modules/articles/article.php?id=77

 

[tanion]

Step by step with pictures:
http://www.bullittarchive.com/html/modules/articles/article.php?id=77

Thanks for the pictures. Hopefully cleaning the MAF will work because right now the car is running like crap.

 

[Kilgore Trout]

Thanks for the pictures. Hopefully cleaning the MAF will work because right now the car is running like crap.

I am starting to think paper filters > K&N

 

[chimchim]

When you say "past due" on that fuel filter, do you mean it's never been changed in 47,000 miles? If so, change it. For like 10 bucks and twenty minutes, it's worth a try. I had an S-10 truck with 80,000 miles and I never changed the fuel filter. It got so bad that it felt like turning the ignition on and off. Anyway, after I changed it the truck ran better than it had in YEARS. From just the fuel filter. Try the cheapest stuff first.

 

[Kilgore Trout]

Step by step fuel filter change with pics:
http://www.bullittarchive.com/html/modules/articles/article.php?id=73

 

[Red2000GT]

A bad oxygen sensor will cause that problem too.

 

[MidnightBlk98GT]

A bad oxygen sensor will cause that problem too.

But that would trigger something in the computer and the CHECK ENGINE light would come on even if it's just a split second hesitation. If the the upstream sensors had a problem, you'd probablly notice instantly but maybe not so with the downstream sensors.

 

[Kilgore Trout]

It is the MAF, it has oil on it from the filter.

 

[tanion]

Thanks for all the suggestions and pictures. I'll be cleaning the MAF and changing the fuel filter this weekend. By Monday hopefully everything will be fine. I must admit I've been kind of neglecting my stang a little since I started riding motorcycles a couple years ago. Time to show the stang more tlc.

 

[GTron]

Sounds exactly like the problem I've been having. If it is, it will progressively get worse and worse. Mine's to the point that when the A/C is running, I can't get up to 30 mph. I've tried cleaning the MAF, new plugs, fuel filter all kinds of stuff. Now, I'm just waiting on my Xcal II so that I can datalog the computer and send the info off to be analyzed. Nobody has had an answer on this.