Still losing power at high rpms WTF!!!

chuckystang

New Member
Jul 12, 2004
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The past month or so I have noticed about 50% of the time when I go wide open throttle and I get above 4k there is a very noticealbe drop in power and noise. I hear nothing that sounds broken or terrible or anything like that, it just gives you that same feeling like when you have the traction control on and your spinning the tires and the computer kills your power to stop them from spinning. Thats just how I describe how it feels but that is not the problem because I made sure that it was off! My air filter is clean and my fuel filter is new. My car has 78k miles (99 cobra) with the original spark plugs and coils for all I know. Could it just be that they need replacing? Or should I check something else? I notice this drop in power the most in 1st gear, but Im ruling out the clutch, transmission and/or the rear end just because my gut instinct says that aint it. I just cant stand it anymore when I mash the gas to only have my car feel like its literally being held back. Not enough fuel? or? Just seems like there could be way too many things that could cause it but other than this my car runs fine, idles great and starts right up. thanks alot!
 
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Check your sparkplugs. Might want to replace 'em anyways w/ that much mileage. It's possible a coilpack could be bad.
Also, is the check engine light on (it doesn't sound like it is, but just checking - perhaps a misfire has been detected)? :shrug: If the light is on, get the computer scanned for diagnostic trouble codes (DTCs) and proceed to troubleshoot/repair.
 
Thanks, no check engine light that I have noticed but I will look for it next time. I had my engine washed apparently incorrectly last summer and had to have the spark plugs or coils or something all blowed and dried out to get it running right, they said last year that they saved them but maybe they have just passed their time, do you know how much those run, and I don't really under stand how the coil on plug design works? Im used to the old distributor with some spark plugs to replace. I have heard its expensive to do this on a cobra :(
 
coil packs are way easy and dont cost that much either I wana say like 70 each I could be wrong but there not that bad to install. And Im not sure if they have them ont he 99s but on my 97 at 4 grand is when my IMRC open to let more air in maybe thats it.
 
You don't have IMRC's....

The coil over plug design is nice because it can support upward of 650RWHP without modification. If you do have a bad coil over, it's as simple as pluging in a new one...the bad thing is the aren't cheap. I think they are like $80 a piece...and I'm not sure how you find out which one is bad. If you want to replace all 8 that would cost around $640 from the dealer.

I found a place on the web that sold them for like $45 each...I purchased two when I developed a misfire in the upper RPM's under boost. I looked at them all and found two that didn't look good, so I replaced those and luckily it fixed the misfire.

To start though, I would replace the sparkplugs and see if that fixes it. The coil in the back on the passenger side likes to hold water....just bad design from Ford.

Start with the plugs and go from there.

Edit....could possible be a fuel problem too....pump might be failing or an injector could be plugged.
 
99SVTAddict said:
You don't have IMRC's....


Heh, I think chuckystang knew that, and Bobby didn't...

Esp since he thinks his open at 4k when they actually open at 3250...

Ahh, but these Cobra's can be sneaky, and seems like whenever there's a problem with them it has to be something dealing with the IMRC's...even if they don't have them... :p
 
Thanks guys, Ill start with the plugs and go from there and hope that I dont need all 8 coils, but the clogged fuel lines is always possible because it literally feels like it just falls flat on its face at about 4k makeing the car ridiculously slow! The thing that may or may not be weird is that it does not do it all the time and I mostly notice it in 1st. But I would say its time for new plugs anyway lol
 
I have some power loss in my 97 as well. There are new MSD coil packs on order right now as well as new plugs and wires. Fuel filter was just changed and injector cleaner ran through the fuel system. I'm hoping this will take care of the problem. The "power curve" around 3200 rpm's is what seems to be missing in my car. It was there a couple of months ago, but all of a sudden disappeared. Good luck.