WOT problem

JasonMiller94SC

Registered User
My Girlfriend's 94 SC has a problem at wide open throttle.
You only start to notice it in 2nd and 3rd gear but I'm sure it's there in 1st as well.

When you stand on it the car just seems to not pull very hard above 3000 rpm. However, if you back off the throttle every so slightly the car seems to pickup and pull harder but then will shift sooner. I've replaced and adjusted the throttle position sensor and that didn't seem to help. The only mods to the car has are a cone filter and a computer chip. The chip dosen't affect this problem as the car will do it with and without the chip in it.
Any ideas on what I should check?
 
The fuel filter I changed when I bought it a year ago. I suppose it could be the balancer but how would I check that? I've taken the belts off and tried to move the crank pully and it was tight.
Wouldn't a balancer affect it at all RPM ranges?
 
WOT Miss

Fuel Filter was the same thing I was thinking. Easiest to replace that first. You should also (even if it's just a year old) check your existing one by removing it and blowing through it and seeing if it has any clogging or resistance to it. All it takes is one cra*py tank full, to clog it up.
You do need the special spring compressing tool to get it out.
They are under 10 bucks and commonly available.
There is also the possibility of a bad fuel regulator or weak fuel pump.
Check the fuel psi at the fuel rail (via the cap w/ the schrader valve underneath it), you should see at leat 35-40 lbs regardless of rpm's.
If you know that's good, and it's getting fuel (here's where it also might help to run a good injector cleaner through the fuel system to clean the injectors), then the next thing I would suspect is an ignition problem.
Put it on a scope and check the coil packs, wires and plugs. Replace anything with too high of resistance. When were the plugs/wires last replaced? All it takes is one plug fouled or breaking down.
See if you can duplicate the problem without it being under load.
Take a look under the hood at night and see if you can see anything obvious such as sparking from a wire, or the crackle of a voltage leak.
Another place it could be is in the coil pack. These are known to fail and deteroriate, causing weak spark and a miss, most notably at WOT and at higher rpm's, as the stronger the signal, the more they break down.
There are many things that can cause this problem, but these areas are where I would check first... Start simple with the usual suspects. If they all check good, then move on to the more complicated things..... Chances are one of these things could be causing her SC miss....
After all, we don't want her losing to any Mustang's she may run across.. LOL
Hope this helps. ~Dave
 
Well she just takes my car for a ride when she wants to pick on mustangs. :)

Let's see.
Plugs have been in there about a year. The are NGK iridums. I put new wires on it in march as I had one go bad so I just did the whole set.

I'll have to get a gauge and check the fuel pressure.

The car dosen't seem to have a miss at all. I fixed that when I put wires on it. It just seems to stop pulling hard on the top end. All it takes is backing off the throttle just a hair and it seems to pull harder.

I could put my old coil pack on the car. I don't think it's a lack of spark. I think you would feel it missing if that was the case.

I've got a tank of gas in the car with injector cleaner in it now. She's trying to drive it clean this week but we'll see what happens.

I'm starting to wonder if it might be the oxygen sensors. The car has thrown a CEL a couple of times this month but each time it cleared it's self about 2 miles down the road.
 
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