Even better than the catco piece...

MagnaFlow 93307

Take a look at the sexy mandrel bends... Not only would that fix your clogged cat problem if that's the problem, it'll make more HP than the stock Y pipe ever did brand new...

MagnaFlow 93307 - MagnaFlow Direct Fit Catalytic Converters - Overview - SummitRacing.com

 

MagnaFlow 93307 - MagnaFlow Direct Fit Catalytic Converters - Overview - SummitRacing.com[/quote]


I really like this one. When I get a chance I'll check fuel pressure and post it up here.

 

For the love of gawd check the fuel pressure already, a 5.0 of this vintage isn't exactly a powerhouse but with a manual trans and 4.10 gears it won't have any problems pulling away from a stop or cruising at 60 to 70mph... when everythig is working as it should.

One other thing I don't think anybody has mentioned is the fan clutch, does your truck sound like it's trying to suck the grill in when the motor is reved? With the engine off can you turn the fan by hand? It should move with a little resistance meaning it won't spin freely if you flick it but you shouldn't need to push on it very hard either. If the fan won't spin at all or you really have to lean on it to move it that means the fan clutch is seized and that will suck the life out of the motor, I mean literally consume half the engine output so it needs to be replaced asap.

 

Fan spins fine by hand and at higher speeds

 

EVERYONE THE FUEL PRESSURE IS 31 PSI when the truck is on the fuel pump and 31 psi when the trucks running

 

Then it's down to fuel pressure and/or a clogged cat. If you only have about 20psi at the fuel rail the motor won't make any power, it will run but it will just fall on it's face at 2500rpm. You should see at least 40psi at the fuel rail with a couple prime cycles... that's the 1-2 second pump when the key is first turned to run. The system should also hold this pressure it should not bleed off. With the engine running you should get 32-35psi with vacuum attached to the regulator and 40-45psi with vacuum detatched or a quick blip of the throttle.. which also reduces vacuum signal momentarally. If you don't get those numbers and the truck has dual tanks then you could have a bad fuel transfer problem which not only syphons off half the fuel but half the fuel pressure, or the pump could simply be weak or maybe it's not getting full voltage due to a corroded connector or bad ground.

 

Just a heads up on the magnaflow y pipe you can find some on ebay for 225 shipped. Waiting on some money to do this and a few other things

 

Summit's price is $224.22 with free shipping...

31psi with the key on, engine off sounds a little low. Try disconnecting the vacuum line while the engine is running and see what you get. If it's still 31 that's a problem. It should be in the 40's at least. Also, if you can, try to drive it with the gauge hooked up and see what the pressure is. If drops into the 20's under load that is definitely a problem.

 

The hose from the connection to the gauge isnt long enough. Is there another way to test? Could I have a friend rev the truck while I read the values at certain incriments

 

If you don't get those numbers and the truck has dual tanks then you could have a bad fuel transfer problem which not only syphons off half the fuel but half the fuel pressure, or the pump could simply be weak or maybe it's not getting full voltage due to a corroded connector or bad ground.[/quote]

If I get a voltmeter to test the fuel pump ground. Where do I test it and what volts should I be getting to tell if the ground is good?

 

Under load is best, but since you can't do that...

With the truck warmed up, check the FP at idle with the vacuum line attached. Then disconect the vacuum line. FP should rise 10-15psi. Then, with the vacuum line back on have a friend quickly rev the engine. This should cause a drop in manifold vacuum and signal a rise in FP. Since the engine is revving the computer will add more fuel. The pump should still be able to keep up and you should still see a similar rise in FP as the first test. It's probably not going to be exactly the same but if it doesn't move or drops you definitely have a problem. Also during the first test if FP doesn't rise you have a problem.

Also, if you have a vacuum gauge, hook it to the engine. At idle it should be at say 20" or so. If you rev the engine to 1800 or 2000 rpm in neutral and hold it steady you should have a similar amount of vacuum. If it is significantly lower like say 15" or less then you have a clogged cat. Or so I'm told by my mechanic friend who has 30+ years experience.

 

OK Ill try that and get back to you

 

So in terms of a clogged cat, I will disconnect my exhaust at the manifolds and see if I have an increase in performance. I can hit 5000 rpm when driving but the truck feels restricted and having to really push so I'll give tat a try as well

 

That works too...

 

But ill do what you said to test for low fuel pressure. I'm thinking now its a combo of low fuel and bad cat.