Please Help !!!!!!

[stumpr]

I have had my SHO MTX for almost a year. When I purchased the car I put new Tyler spark plug wires and Bosch 4 series Platinum 4 plugs. Soon after I put in a K&N air filter. Three months later, I installed a MTX Y-Pipe and Dyno-Tech exhaust. The car runs well but seems to lack power and accelleration past 5000 RPM. I recently had my SHO on a dyno last week and I discovered that I am only generating 150 HP at red line (7,000 RPM). To be on the safe side, I also had a compression test to determine if there was a problem with my cylinders. The compression test results indicated no compression problems. Does anyone have any ideas what could be wrong? Have talked with several mechanics who want nothing to do with diagnosing SHO problems.

Even if you have no ideas concerning my problem, does anyone know and good SHO mechanics in the Northern Virginia or Maryland suburbs of Washington DC?

 

[Mr Anonymous]

First, toss the Bosch plugs in the trash and go with stock Motorcraft or Autolite double platinum plugs. What kind of maintenance history does the car have besides the plugs and wires?

 

[somedude_001]

let us try and help you before you go taking your car to someone else.

there has been quite a few people on here that have had problems with the +4 plugs infact everyone I know that has used them has had problems with them. maby not toss them because they are expensive but go back to the parts store and see if they can exchange them for another brand or something, only motorcraft or autolite double platium.

 

[rangerj]

Look in the search feature for "pulling the codes". If the problem is electronic the computer will store codes. If you do not have any codes, the problem is mechanical and not electronic. For example, the timing belt could be off one tooth.

You do not need any special tools to access the codes. A simple paper clip or short jumper wire will work. However there is a procedure to follow, so read up on it and get back to us if you have questions. In fact I think Auto Zone will check your car for codes for free, so you could also thry that if there is an Auto Zone near you. rangerj

 

[stumpr]

Thanks everyone................I guess I will try the stock Motorcraft plugs and see if that helps. Will also try and read the codes to see if it could be an electrical issue but so fat, there is no yellow light.

 

[Whiner]

Does the car use more gas then it should? Or misfire? Maybe the air silencer is clogged with leaves/debris?

 

[I'll sho u]

you should also sheck to see if the gas filter is dirty and check to see if the fuel pressure is up to *****.If it is not that could cause real problems especially at high rpm

 

[stumpr]

the car really runs good no type of misfire or anything like that. I will check the gas filter because the car really does have a problem at the higher rpm. Thanks

 

[Bizzy]

Codes, codes, codes. Get the codes first before doing anything else aside from replacing the plugs. Verify that the plug wires are seated properly. Verify that your secondaries are opening up when they should be. Check your fuel pressure at the rail prior to replacing the fuel filter or pump. If the pressure is good then there's no need to replace either.


I'm assuming that the y-pipe you put on has cats. You might consider taking a moment to verify that the cats aren't damaged inside, they can cause some serious power loss as well as being quite dangerous.