Loss of power

I recently experienced a severe loss of power in my 89 SC, 140,000 miles. I changed the air and fuel filter but neither helped. The plugs have about 15,000 miles on them.
The car builds boost, but has no punch. I am thinking about looking into the fuel pump pressure, but am not sure how to test.
I have no evidence of bown head gasket, loss of compression or loss of fuel economy.
I am looking for suggestions...any would be appreciated....

this hot weather will greatly reduce power but when my balancer went bad it gradually got worse till it wouldnt go uphill.it would make boost like normal just wouldnt go , even reved slow in neutral like it was late on timing , and it had no wobbles , i hated to take it off when i wasnt sure . but that was it, you could also check and see if the maf is dirty . or it could be fuel pressure regulator try some stp gas treatment

I just replaced the fuel pump and monitored the fuel pressure. it runs about 40psi under idle and increases is the engine is revved. Am pretty suer at this point (i have also replaced the filter) that the issue is under the hood.

What is the MAF?

Ty Whutaker said:

I recently experienced a severe loss of power in my 89 SC, 140,000 miles. I changed the air and fuel filter but neither helped. The plugs have about 15,000 miles on them.
The car builds boost, but has no punch. I am thinking about looking into the fuel pump pressure, but am not sure how to test.
I have no evidence of bown head gasket, loss of compression or loss of fuel economy.
I am looking for suggestions...any would be appreciated....

Click to expand...

Without any further symptoms it's hard to tell what's going on. Maybe you could give a detailed discription of what's happening.

Check all vacuum lines for leaks. If none are found and the Fuel pressure is fine, it could be a sensor. Most common ones are the Cam and Crank Sensors.

If you have a code reader you should start there. download the codes and post here and someone should get back to you. You can get a cp9015 for about $30.00 at a parts store or find a document on shorting out the test connector.

I just replaced the fuel pump and monitored the fuel pressure. it runs about 40psi under idle and increases is the engine is revved. Am pretty suer at this point (i have also replaced the filter) that the issue is under the hood.

What is the MAF?

I would like it if there was a CE light, but there isn't. what other codes are available?

Wouldn't a cam or crank sensor fault cause the car to run rough? it really runs smooth, it just has no punch...

Ty Whutaker said:

I just replaced the fuel pump and monitored the fuel pressure. it runs about 40psi under idle and increases is the engine is revved. Am pretty suer at this point (i have also replaced the filter) that the issue is under the hood.

What is the MAF?

Click to expand...

The MAF is the Mass Air Filter. It's that metal piece that goes on to your plastice intake hose right after the air filter box.

Ty Whutaker said:

I would like it if there was a CE light, but there isn't. what other codes are available?

Wouldn't a cam or crank sensor fault cause the car to run rough? it really runs smooth, it just has no punch...

Click to expand...

Ok so you don't have a check engine light coming on. There may still be some codes. I don't know how, but there's a way to jumber off the diagnostics connector to get it to dispaly on your console's check engine light. If the light doesn't come on then, maybe the light is burnt out.

Some other check points...

• Plugs, how old are they?
• Wires (ditto).
• Air Filter (ditto again).
• Possible clogged injector.
• Oil, is there a lot of consuming?
• How much boost do you get a WOT?
• Is you blower belt slipping.
• Does your blower have fluid in it?
• Does your clutch or transmission slip?
• Is your TV cable attached to the accelerator linkage?
• Does the car over heat?
• Is the coolant requiring frequent replenishment?
• Possible clogged Catalytic Converter
• Loss of engine compression.
• Check the motor mounts to see if they’re shot.

These are just a few things.