bignickwaite

Hey everyone! Thanks for all your help on the last few threads I've posted you have been much help. OK now heres the problem..lol .. 98 G.T. Vert . Once the car warms up and has been ran for about 5 minutes or so ( it gets progressively worse the more you drive it to the point of stalling out if you give it gas) your driving along at any speed lets say 4th gear 55mph you want to go so you press the gas pedal down and drop it into second, it starts to accelerate but it also starts to bog a little , it wants to go but it almost kinda go's, bogs,go's bogs kinda thing. Now after about 20-30 min of driving it won't go at all when your trying to accelerate not any gear. It idles fine but give it gas and it starts to bog down and shake and possibly stall. This happened at a stop light the other day and i couldent go anywhere it was embarrassing ..lol...I pushed it to the side of the road and let it sit for about 20 min. I then started it back up started to drive it and at about the 5 mile mark it started to lose power, I was consistently pushing the gas not on it or anything just trying to maintain speed and then it started to bog till it stalled and I had to pull over for another 20-30 min.OK now heres things I have done to try to fix it with no success.. Pulgs , Wires , Coil Packs , Cleaned the I.A.C. , Cleaned the M.A.F. , Going to change the fuel filter tomorrow. The plugs,wires,coil packs fixed the hesitaion problem I was having but no luck on the other problem. So if you have any suggestions any would be greatly appreciated. Thanks as always - Nick

Alex46

Sounds like we are going through the exact same thing. Mine started doing it Saturday out of nowhere. When I try to give it half or full throttle it wants to go but don't. If i ease on the gas it will speed up much faster than half throttle. I doubt it's the fuel filter. Was the first thing i tried. I got the error code of 'fuel line sensor malfunction' so i changed that, but all it did was not die on me. That is until i got a mile down the road luckily next to a parts store. Cleaned everything you mentioned except plugs. Left there and it would get going better than it had the whole time. Trouble was when i stopped. It was idling at half what it usually does and when the light went green it took about 200 yards for it to get going. At my friends i tried to leave and it just died. So i sprayed some throttle body cleaner in it and it was good enough to make it home. But still won't accelerate like it's suppose to at all. And when the A/C is on it's like i am losing over 100hp. I think it's gotta be something to do with the computer. Are all your gauges fine as well?

Alex46

Has anything you tried helped it?

This guy on this other message board gave me some really good advice. Here is the link

http://www.allfordmustangs.com/forum...ml#post2188167

bignickwaite

Nothing as far as the main problem .. plugs and wires coil pack fixed the hesitation problem I was having while driving at a constant speed but other than that nothing to fix the bogging down problem..My Gauges work fine execpt for the fuel. I changed the cluster with another one and everything worked fine till the other day and I filled it. Then it stayed on E for a while then it slowley went back up to full.

Alex46

Was yours not accelerating as normal when you hit the throttle and the plugs fixed that? Just want to make sure I'm reading that right

Also check that link above. That guy had some good tips to try

bignickwaite

No the problem the plugs coil packs wires fixed was when i was at a consistent speed it would miss a little a light buck you could say.. that is completely gone now. but the car warming up and losing power when i accelerate is still there..

uberstang1

It sounds like you changed almost everything involved in the ignition/fuel department minus a fuel filter/fuel pump/injectors. Is the CEL on? Also is this car an auto or standard? I'd try running a compression check as well. I blows out intake manifold gasket/plenum gasket may cause a problem like this, can u hear or feel any air pulling/pushing from these areas?

bignickwaite

LOL... Whats the C.E.L. ???? lol... Its an 5 speed as well. Ill tell my mechanic tomorrow to check the compression he has all the gauges to do it so that will help.Im going to go check in a little bit with some carb cleaned and listen for some leaks in the motor compartment. Thanks ill check these things and narrow it down some more.

03 GTswag

CEL= Check Engine Light, Do you have cats in the exhaust if they are old and clogged up that can create the same problem you describe, i had that happen on a car that was not a mustang, just my 2c

bignickwaite

Yea I'm and idiot ..lol..i should have figured out the CEL..lol.. yea I have cats on it and no after market exhaust so I plan on getting that done as soon as I have $500. to spend on it there is a bunch of heat that comes from the center console area from below the radio to behind the emergency brake. Now i just got back from discount auto parts had him put a computer to it and code p1131 came up which is :

P1131

Lack of Upstream Heated Oxygen Sensor Switch - Sensor Indicates Lean - Bank No. 1 .

So could this also be the problem an oxygen sensor?

Also I know I have 2 vacume lines off i posted it in my previous post and I still cant figure out where they go . I cant find anything missing of the plenum no nipples or anything so I'm so confused..lol.. but the one line sucks and if you suck on it when the car is off you can taste some gas fumes .. lol heres a link to the old post with pictures :

https://mustangforums.com/forum/4-6l...t-i-found.html