1995 GT Engine Lacking Power
 

I am new to the mustang world as I just picked up a 95GT Convertible today. It is an Automatic transmission with the 5.0 Engine. The problem I noticed right away is that the engine seems to loose pretty much all power at anything over 3500rpm. Is there something I am missing here or is it the fact that it has 146k miles on it? It runs awesome on the Low end of the RPM scale. Any Ideas?

it may have clogged cats, if they are on the car, or maf may be dirty, also first in line to check would be run a koer test and see if any culprit codes exist:)

tune up, new plugs, cap n rotor, wires, fuel filter, clean the MAF, check fuel pressure (~45 psi static), look at the trans fluid, change the oil (use an FL-1A Motorcraft filter).

the problem is called E7TE heads btw...

Thanks for the ideas! I have always been a GM guy so I have a bit of learning to do. Is the "koer" test the same as an OBD scan?

Key On Engine Running test. Yes, it is an OBD scan. Search the forum threads for the method to do this. I would also suggest you get a shop manual for your car. It is filled with good diagnostic methods.

I had a spark plug come loose and it would not rev past 3000.

oh yeah, check and see if the air filter is dirty, mine was and when i got a CAI it was a night and day difference...

if you want one, dont bother with a name brand, get a no name off American Muscle, theyre all the same.

Ok I have done the KOEO test first. Definitely a 33 right away... THen it looks like 14,44,95,42,53..... They run pretty fast! I'll look up the codes and start there. Wouldn't it be easier to just hook a scanner up to it? Is there something that we get this way that won't show on a scanner? Is a 95 OBDI or OBDII?

Alllllll Right... I broke down and bought a scanner. I got a 113 which is Intake air charge Temp. Sensor Fault (Low Volts)
157 - MAF Sensor Fault (Low Volts)
158 - MAF Sensor Fault (High Volts)
172 - HEGO (HO2S) Sensor Fault Lean
176 - HEGO (HO2S) Sensor Falut Always Lean

Now I am wondering if the first 3 codes are from me disconnecting the MAF and Temp Sensor when I was removing it to clean it off.

I am going to see if I can actually clear the memory and have it regenerate new codes.... At this point my money is on the cats being plugged!

I had a simular issue with my wifes '95 GT,seemed kinda down on power.I have drove and rode in other 5.0 Mustangs in the past and new something was not right.

What i did/had done...

New plugs and wires,tranny service w/ shift kit,bump up timing,fuel filter,cleaned MAF and K&N filter,seafoam treatment through the intake.

Before the car would have a hard time even pulling to 70mph and was always bogging down.Now she'll pull hard to 100mph no problem.Better mpg,better throttle response,better shifts,shoother idel,ect...

Her car has a off road H pipe so cats were not an issue.

If its running lean, its not going to have any power.

I would start with cleaning the MAF as suggested by everyone else, then run the KOEO and KOER codes AFTER the codes have been cleared once the MAF is clean. If the same codes come up, you will have to test the MAF unit with a DVOM and a wiring diagram :)