help me i have problem with my 99stang. The problem is that when i do full throttle at 3d gear and the RPM comes at 5500 exactly my stang lagging or something semellar to cut off and come back to normal and lagging again and back to normal until it reach the red line and some times this thing come when i am at 140KM speed for lone time suddenly it comes out like cut off. There were no codes for my car just the 02 please help me

 

Sounds like your fuel pump or regulator is dying. Perhaps as simple as a new fuel filter will fix the problem. Mark

 

Good lord, was that even english? [8D] Just messin. Try changing the fuel filter as said above and just for the sake of maintanence change the plugs too.

 

For plugs I have had very good luck with NGK platinums. Pre gapped with a pencil point center electrode. Actually picked up .1 according to the timer I use for street testing. Well worth the $3. each. Mark

 

i chaged my plugs and nothing changed.

the problem now is when the rpm reachs 5300-5500 in 3d gear only it cut off like it reaches the red line some friend told me to change the computer and i want to know is it the computer or i have to change the ful filter and plugs wires.

and forgive me for this bad english and i hope u understand me

 

I don't see the computer going bad and affecting only third gear between 5300-5500 rpm. It does not make any sense. It could be a number of things. Maybe even O2 sensors.

A new fuel filter never hurts. Maybe a pump or regulator, but that doesn't really fit. When you say "cut off," what exactly do you mean? A loss of power or the engine shuts down? The lack of codes does not help at all.


What type of transmission do you have? Guys, could this be caused by a slip in the clutch or maybe a bad stall?

 

sorry to say, but your friend doesn't know what he's talking about. besides you always find the cheap fixes before you start looking for the expensive problems.

 

hi guys, i mean by cut off is that the rpm stop like he reached the red line and also the speed stop i dont think the 02 sensor will do this by the way even if it was in the 4th gear and reached the same speed or more a little it will do the same thing. i hope guys u understand me now if u didnt told me to explain more.

 

sounds like a fuel filter or fuel pump try the filter first tho its cheaper

 

if you're in an AUTOMATIC this is perfectly normal, unless you force the gear, your auto wont rev past 5,300-5,500 on its own....

if its NOT an automatic, i dont see the FUEL pump causing a problem, considering it should be pumping more gas to the engine at 4,500-5,200 rpms compared to the 5,300-5,500 hes troubling with. but eh, who knows. just wouldnt pinpoint that myself as the culprit. from your first description it seems like you can still rev up to redline, but it hesitates/jumps around from 5,500 to redline. how often does this car been operated at these rpms? and it could be your power just cutting out, 4.6's lose power around 5,400, quite significantly, although the other night when i took my auto to 6,200 rpms i didnt feel any cut out, but it was the first time i had ever done it.


does the car have a tuner or any major mods?