1995 Cobra "Fuel or Exhaust Issue"

[one95cobra]

Hi All
Love to read your posts and responses here. I have had my 95 Cobra Since 96 and love it, however It has lost half its power and can't breach the 3500 RPM mark anymore. I have replaced the plugs, fuel regulator, and fuel filter, air filter, O2 sensors, and airintake sensor. I am probably the poorest ot all Cobra owners so cost is a big issue here, but willing to spend thriftly to fix the right part.

I put a fuel pressure gauge on it and it was within limits but it was at the lower end of the scale. I pinched the return hose and the pressure shot up to twice the normal reading which the manual said was normal. However when I turned off the engine the pressure would not hold even with the new regulator. My question is, should I go with the pump or do you think the exhaust might have too much resistance to achieve the higher revs?

The engine idles fine and appears smooth but just stops at 3500rpm's. What should I try next?

Thanks for your help.

Mike

[lowflyn]

Are there any codes being thrown? Also, around how many miles do you have on the car? It could be the pump but might also be a restriction with clogged cats or something similar.

[one95cobra]

There was a code about the secondary voltage to the pump but I could not find out what that meant. Also the voltage measured at the shutoff switch to the pump is only 9V.. Not sure if this is a problem either. Oh! there is 150,000 miles on her.

[Zim]

are you cat converters clogged up??? Is the car mostly stock or what?

[one95cobra]

Would of liked to of increased the horse power a tad but haven't as of yet. So it is completely stock. Guess I should replace the exhaust system first. I have read some of your post on other threads. Would installing one of those Roush side exhaust systems be recommended? They sure look nice.

[Justin]

my car was doing something kinda like that before and i replaced my fuel pump...when it would get into the higher rpms it would sputter...

[MonteCitan]

if its not holding pressure it could be you have a bad injector or two..

[Zim]

I would say take it to midas or some other muffler place and have them check to see if you cats are clogged...

I remember my dad had a jeep cherokee that this happened to and the thing wouldnt top 40mph... its worth a shot.

[lugthug713]

I would say the cats are clogged

[one95cobra]

Well here's some updates of what it's not. Changed fuel pump... no help. Changer the ICM (ignition Control Module, no help other than the pressure now holds after engine turn off. had a suggestion to remove the O2 sensors to relieve pressure in the exhaust which will indicate for sure if the cats are clogged. So that's my next step. Thanks for all the suggestions. They do help.

Mike