Ford Mustang Forum banner

Status
Not open for further replies.
1 - 20 of 34 Posts

·
Registered
Joined
·
36 Posts
Discussion Starter #1
I have a 98 Gt, 4.6. It has been doing this for a while so I replaced the plugs and wires already. It has a K&n filter also. It is a 5sp.
In any gear, if I hit the gas to the floor, the car holds back and the rpms only go to maybe 4k or so. If I let off of the gas pedal a little, it actually improves the performance and will go to higher rpms and accelerate. Please help. Any suggestions?
 

·
Super Moderator
Joined
·
39,982 Posts
i would check the t.p.s.,,,you have any codes?
 

·
Registered
Joined
·
36 Posts
Discussion Starter #3
The check engine light isn't on. If I had any codes, wouldn't the light be on? Also, it runs smooth as if nothing is wrong. this condition is only noticed when you hit the gas to the floor.
 

·
Super Moderator
Joined
·
39,982 Posts
have you replaced the fuel filter lately?
 

·
Registered
Joined
·
36 Posts
Discussion Starter #5
Actually I never have since I've owned the car. Can you tell me where it's located. Any special tricks I should know about changing it, or is it like any other car.
 
R

·
Guest
Joined
·
0 Posts
i would check the t.p.s.,,,you have any codes?

nah the TPS's used on the modulars since 1994 have been almost 100% trouble free...I'd say it's either an O2 sensor issue or maybe a fuel pump going south...how many miles on it?
 

·
Registered
Joined
·
36 Posts
Discussion Starter #8
I have 39,000 on it. I think the fuel filter suggestion sounds like a possibility. you think it's a tps? The car has been sitting for years.
 

·
Registered
Joined
·
145 Posts
I had a similar problem. I would stomp it and it would only go to around 4000 rpm and stutter. It was the coil packs. I brought it to three different mechanics before they could figure out what the hell it was
 
R

·
Guest
Joined
·
0 Posts
I have 39,000 on it. I think the fuel filter suggestion sounds like a possibility. you think it's a tps? The car has been sitting for years.


no, leave the TPS alone:nono:..... so the car's been sitting awhile:scratchchin well could be the fuel in the tank has gone bad, gas starts to go stale after @30 days....drain and re-fill the tank, if you haven't done-so, replace the fuel filter and sea if that helps................
 

·
Registered
Joined
·
36 Posts
Discussion Starter #11
I'll change the filter probably tomorrow. i can leave a post to let you know if that fixed the prob or not. i hope it's not the coils, i hear they're kind of expensive. I should just sell my car. anyone want a 98gt with 39k original miles on it.
 
R

·
Guest
Joined
·
0 Posts
I doubt it's the coil packs, they are pretty much bullitt-proof, I've seen them go 10/12 years and over 150k wthout any issues....onemore thing to look at is check all the wires to make-sure some small furry animals didnt get in there and chew on 'em....
 

·
Registered
Joined
·
36 Posts
Discussion Starter #13
I actually did that already. however, it runs smooth and doesn't miss or anything. the only problem is when i try to hold my foot to the floor.
 

·
Registered
Joined
·
16 Posts
I am having that same problem as well!!!! I don't know what to do! I have an 02 Auto. If you happen to figure it out PLEEEEZE LET ME KNOW. I am still working on it so if I figure it out I will leave you a post.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #15
hey vinny boy, that is very interesting that you say you have the same problem. lets make sure we return to this post and update it when we find a resolution. yours is a 02 so it really shouldn't be a fuel filter problem. hmmmm. i wonder if this will solve my problem or not. we'll keep in touch.
 

·
Registered
Joined
·
36 Posts
Discussion Starter #18
I don't have a traction control system. Today i'm going to check the voltages on the tps. we'll see how that goes. I also read somewhere that it is important to replace items like this with oem ford parts and not aftermarket.
 
R

·
Guest
Joined
·
0 Posts
I don't have a traction control system. Today i'm going to check the voltages on the tps. we'll see how that goes. I also read somewhere that it is important to replace items like this with oem ford parts and not aftermarket.

dont bother as TPS voltage is reset each time you start the car and the TPS on our cars is has never been an issues like it was on the old 5.0's.....I'm still saying old/bad fuel or bad O2's, or a combo of both.....
 

·
Registered
Joined
·
36 Posts
Discussion Starter #20
I checked my tps voltages. the idle voltage was about 1, the full throttle was about 5 and the reference voltage was about 4. those are all within the normal range.
I won't be able to get my fuel filter put on until monday probably. i have my seat out because i am working on the power switch and i won't have the new switch until monday. although i know how to replace a fuel filter, you're not allowed to work on cars where i live here in south florida.
 
1 - 20 of 34 Posts
Status
Not open for further replies.
Top