Accidentprone

I have a 1994 GT, in the last week I've noticed a large power loss around 4000-4500 RPM. I've owned the car for two years, so I know that the power curve drops off in the upper RPM, but this is a lot more loss than normal. The acceleration stops completely and the engine revs very slowly at that point.

I'm thinking that it could be the fuel pump, but that's just a semi-educated guess so I'd like another opinion. The spark plugs have maybe 7,000 miles on them and are properly gapped, the fuel filter has about 3,000 on it.

Is there something else that it would be more likely to be, or would the fuel pump be a good guess?

Canary94GT

Could be clogged catalytic converters

You might also try cleaning the MAF sensor with some MAF sensor cleaner, just something that is a good thing to do if it hasn't been done in a while.

How many miles are on it?

Accidentprone

About 110,000.

Accidentprone

Since I can't find edit post I'm going to double post, if it was clogged catalytic converters how would I check? The MAF sensor hasn't been cleaned since I've owned the car, I've been hesitant to do it because a friend of mine used the cleaner on his car and it ran poorly for a few weeks afterwards.

Canary94GT

Well as long as you use MAF sensor cleaner spray and are delicate with handling it, you should be fine. Here's a guide: http://www.mikefordmustang.com/write...ustang-maf.php

You can test your catalytic converters by hooking up a vacuum gauge to the car. When hooked up and the engine is warm, hold the throttle at around 2500-3500 rpm and watch the vacuum gauge to see if it drops over time, this would indicate a build up of a pressure by clogged cats.

There are other ways to test, such as connecting a pressure gauge to the exhaust from in front of the cats and see if the pressure is in excess of about 1.5psi. If it is, you need new cats.

You can also buy an infrared thermometer gun and check to see the temperature of before and after the cat, it should be hotter after the cat than before. If it's not hotter, your cat is probably clogged.

Accidentprone

Alright, a friend of mine has an infrared thermometer gun so I'll try to get that from him and check with that. How urgent would it be if this were the problem, I ask because it is my daily driver and I drive to college every day. My fall break starts next Thursday, so if I waited until then would it be a problem?

I'll get some MAF cleaner and do that over the weekend, thanks for the link on that.

If neither of those are the issue, could anything else be the cause?

Thanks for your answers and help so far.

And for some reason now the edit box is showing up. Oh well.

Bubba 95SN

Hook up fuel pressure gauge go for a run. Do EEC 1V tests, post results.

Canary94GT

oh derp, good point Bubba, you should do the self tests first : http://www.muscularmustangs.com/test1.php

They'll help a lot with the diagnosis of whats wrong if the computer has detected a problem. Post back here what codes you get.

Also, you should be fine continuing to drive it as long as it doesn't get worse and it's secluded to the 4000-4500 rpm range. Keep an eye out for noises or abnormal gauge readings just in case though to be extra safe.

But the self tests are something you can do quickly and right now with just a paperclip, piece of paper and a pencil and will tell you a lot.

Accidentprone

I realized that I never replied to this thread, on the off-chance that either of the people who were helping me sees this I just wanted to say thanks. I was able to get ahold of a pressure gauge and found that the cats were clogged. I had them replaced and its been running smooth since. Thanks again.