That's pretty much not debatable - get it done!

I agree - ignition.

 

No way in hell that is valve float. I know valve float, and that aint valve float. Valve float will look like a fast power fall off around 6K or so.

Put a fuel pressure gauge on and rule the pump out for good. The stock fuel pump should be fine for your setup. I am still running the 14 year old stocker on my setup.

Lifter preload also has nothing to do with it. Run 1/4 TPZL and lock it down.

This absolutely looks like ignition to me. Maybe a bad plug wire or the optispark. Check the wires for damage and other possible loose connections.

Make damn sure the plug wires are on the right plugs. As simple and stupid as that sounds, mine was recentrly running like *** and found I mixed up 3 & 7. Make sure the injectors are hooked up right. Since you are OBD 2, maybe there is a code.

 

That is the first thing I thought too when I looked at the graph.

 

If you end up getting a opti I would order one from thepartsladi on ebay. They have gm delphi opti's for $255 shipped.

 

Ok, I think I found my pink elephant. I checked all the springs while I was setting my lash to 1/4 turn, they all looked good (I expected that). I was going through the spark plug wires, then noticed the #6 wire was a little loose. I look inside the boot, and there's white powder. I'm guessing it worked itself loose and the wire was arcing to the plug.

Cleaned it out and put it back on. I plan on changing it out when I get a new one. I was going to pull the plug to check for fouling, but I don't have my SLP plug socket.

I'm still waiting on the power drill to charge so I can remount my 6AL on the firewall. After that I'll try to find an empty road where I can take it to redline and see what happens.

 

there you go, white residue is from arching

arching causes high rpm miss

 

So if it was a loose plug wire, it should have idled like crap and produced a definitive missfire which OBD2 should have recognized. Sounds like your almost there.

 

not necessarily if it wasn't a huge arch

sometimes an arch can only cause problems under a load

 

I had two wires crossed and really couldn't tell it, at idle. I guess the cam camoflauged it.

 

Depends on the two wires. Different incorrect connections will do different things. When I had 3 & 7 crossed, it had a funny idle and started to pop especially under load.

 

It's not crossed wires, I checked them all. It's a fried #6 wire (arcing in the boot). MSD is sending me a replacement free of charge and I'm going to pick up another plug from Autozone. The miss is worse and I can definitely feel it at idle. Still no SES light. My scanner is in the mail so I'll be able to check my misfires soon.

 

Where did you have the dyno done and what did they charge? I am thinking of putting my car on the dyno.

 

well I was goin to suggest also checking for what you found. and yes, mis.s can feel alot diff. from time to time, depending on how its bad and how bad it is. and yes, sometimes only can be felt under load as suggested. anyways, Id say you still need a real tune. atleast send it back to pcm4less and have them adj. it for better WOT afr.

good luck and let us know of the results when your done. my auto with MY ported heads on a MUSTANG dyno through a 3800 stall put down 320rwhp unlocked. so your knowwhere near where you should be. Id guess you should be somewhere around 400rwhp on a dynojet. although admitadly I have no idea what your cam specs are. Id guess 2teens duration?

btw, my weak 383 ran consistant 11.7's but I know there was more in it. just didnt have the money to change out other things for a better combo.

 

The high RPM miss threw me off a little because at first it was only under load. It would rev to redline in neutral just fine. But now there is an all time miss, so I hope this will fix my problem.

The cam is 222/230, so I'm hoping to be close to 400. And I definitely want to get a dyno tune sometime, except I just spent money on a good scanner so it will have to wait.

 

oh yeah, also thought Id add. my mail order tune drove perfect (madwolf) except a little black smoke at WOT. got a real quickie dyno tune (2 pulls, one before and only one after minor tweaks to the tune to lean it out a bit) and picked up 20rwhp on that mustang dyno. so I know it had a little more left in the tune even after that. so Im curious how much of your problem is the tune being off compared to how much of it due to the misfire.

good luck dude.