Thread: 5.7 Vortec. No Power

no problem. I found a wealth of knowledge right here among new friends. thanks to everyone!!

nestech has a real good point about the cats if the back pressure at the 02 bungs seems high at all and you can't find a weak cylinder as mentioned above I would consider unbolting the Y pipe at the manifolds(depending on the studs condition of course) or the cat and run it open exhaust somewhere you aren't going to get a ticket if it livens right up you have your culprit also a plugged cat gets the exhaust crazy hot which would...

Happy to hear you got it straightened out. Thanks for posting back with the update.

Quote: Originally Posted by B&B Now where did you learn that little test from? A little birdie told me......

Quote: Originally Posted by Racer593 Nout sure but probably just pressure. You know small town, small shops...AND a tight a$$ that just can't bear to take it to the stealership.(one of my guys IS a Goodwrench service manager with a Tech II at home though!!!!) Chris Even with a tech 2 It is only as good as the guy using it.

60 - 65 psi is the correct fuel pressure. If it maintains 62 psi while running, the pump is fine.

I was just thinking ....... 62psi seems low. I thought the fuel pressure test was to put the gauge on. Turn the key to build fuel line pressure. I believe 70-90 psi. Then turn the key and see where the pressure is at 1 minute. If it drops below 68 then your pump is bad. I remember going through 3 brand new GM pumps before finding a good one. It can happen.

Yea check it out FORSURE, Dont assume becuase it does sound 100% like what mine did. I had to replace it 2 times in 2 years on one truck. They are not expensive to buy. If I remember they under 20 bucks. I'm betting its the TPS but if its not just return the part. They give you a hard time returning it, tell them its not the right one and you already got the right one from another store Only thing that makes me wonder is why you dont have...

What was the final verdict????

Vac leak/intake gaskets?