LT1 POWR

The first run (5) is the stock tune with the original computer.

The second run (1) is with the mailorder OBD1 conversion.

And the third run (9) is the stock computer with some dyno tuneing.

These are all with the mods in my sig from about 4-5 months ago.

Let me know if everything looks alright. Im still trying to figure out some knock problems, which i think are false.

BlackScreaminMachine

It was pulling nicely until 5 k rpms. One thing I would look at is fuel, put a pressure guage on it, run it on the dyno and see if its dropping. I know the A/F looks good.

LT1 POWR

Will do. But where can i get one. I would also like to mount one inside the cabin so electrical preferably.

Do most stock valvetrains keep pulling past 5000 rpm.

WS Sick

You shouldnt have any problems with a healthy stock valvetrain up to around 58 to 6000 rpms on a regular basis.

Summit and Jegs both sell an electical FP gauge and sender.

MeanGreen97Z

It will level off but should pull strong until about 5400 rpm then begin to decrease rapidly. How many miles on this motor? I'm thinking you might have some bad valve springs.

BlackScreaminMachine

just for now you cang et a guage from auto zone thathooks up to the fuel rail, just for now, and you can use it on all cars

LT1 POWR

Shes got about 77,000 miles on her. Mostly highway though. In her former life she was daily driven about 100 miles a day to and from work.

And that fuel pressure guage just mounts to the schrader valve right?

MeanGreen97Z

Your graphs arent showing up for me. Can you email them to me? Maybe post a link?

BlackScreaminMachine

yea, mounts to the valve, with the hood open you can tape it to the windshield.

HOw do your plugs look, any of them rich/lean??

LT1 POWR

I havent pulled the plugs to look, not sure what rich/lean plugs would look like anyway.
Here is a link that might work fo you.
http://www.gmmodernmuscle.com/fileup...ited_copy1.jpg

MeanGreen97Z

Im calling valve float.... worn valve springs. There is no consistant decline to the hp above 5000rpm. There may be something else amiss but the valve springs are definately not helping.

LT1 POWR

So what should my fuel pressure be at idel/cruiseing/and WOT.

johnny3986

My fuel pressure at idle is ~34-36. Cruising it is around 42, and WOT it is at 42-45. I dunno bout the WOT, my eyes are usually on the road.

Lean plugs are white.
Rich plugs are black.
Stoich plugs are tan. (.....right??)