Outdrive1

Here's what I got. 502 mag (MEFI 3) with Dart Pro 1 heads, full roller, cam with 632 lift @ 246 duration intake and exhaust, Vortech supercharger, extrune honed intake and Lightning headers. I ran it with the blower on the stock motor for a a hundred hours before the heads and new cam. After the top end rebuild I had it over to AZSM to tune. They ran it, blew up the drive and gave it back to me three weeks later dirtier than my boat has ever been. Especially since I put a new Pirelli floor in it this winter and redid half of my panels. So I refuse to take it back to them. They welded the clutch cone to the drive shaft so that means they shifted it at high rpm, that's their fault as far as I'm concerned.
Any how, the first trip out it ran really well, I had it up to 5000 or so rpm and it had gobs of power, the idle sucks but I understand the cam doesn't give my map sensor much to go off of.
Second trip out, I changed the plugs and wires, trying to get a little bit hotter plug and putting some new wires on since my old ones were stock. Getting on plane it wouldn't rev over 3500 rpm (might be a little less or more). I figured my plugs were too hot and maybe my knock sensor was going off.
Third trip, I changed plugs back, same thing. 3500 again. I figured maybe my knock sensor was putting it into reduced power mode?
I have now changed back to my original wires, cleared my codes (I have a scan tool), put a new knock sensor in, changed my IAC motor (thought it would help with my idle problem), changed my coil, checked all my ground and positive wires ( have 12.6 at the alternator, starter, battery and both sides of the ignition switch), changed my fuel pump (brand new Aeromotive 11108) ditched the cheesy Carter AZSM put on, checked for pressure at the manifold while running (40 to 60 at idle 70 to 80 at higher rpm), changed the fuel separator. I don't know what else to throw at it. I even found the white wire that comes of the j2 side of the plug that's set up to be grounded and give you a rev limiter in neutral (mine has a plug and goes right to ground), I ran a new ground there just in case. Still doing it on the hose........ WTF could be going on? I'm at a loss and refuse to send my boat back to AZS and Latrine..... Can someone else do my computer without actually running the boat? Or where can I take it in Phx or LHC?

fishead

This is not an insult and dont take it personally,but this is from personal experience and it took me a long time to figure out.I did the same things with plugs and WIRES.Found out after some long trouble shooting I F***ed up the wires because they are difficult to see with all the exhaust and crap.It was only two wires swapped.Made them right and fixed the problem.I hope that is all that it is.

Outdrive1

It's worth a shot, I'll double check tommorrow. I could have mixed one up, when I put the old plugs wires back on I just started at one end and finished at the other.

fishead

If you put the new wires on wrong then just did what you said with the old wires it would still be messed up.

Outdrive1

I wish it would have been that easy, wires look to be in the right places. 18436572. What's wierd is that sometimes if I hold it open it will kinda shut off at 3500 but then rev all the way up to 5k or so. It's like the motor has a big flat spot right in the middle.

stevesxm

let me say that that fuel pressure sounds very very hi to me...and im assuming that you don't see a dramatic drop when the thing goes flat...

at anyrate... my 502 did the same thing.... turned out to be 1 bad injector shorted electrically... and because the fire in groups of 4 it was doing something very bizzare to the other three.... at anyrate... i took out all the injectors and used the scan tool pulse function to check them... found the bad one, changed it out and everything was fine. and i had spent any number of hours checking everything else first...

i drained 200 gals of fuel ...convinced it was bad... etc etc... bottom line... one bad injector did exactly what you describe to me.

Outdrive1

Well something I changed fixed the problem, ran fine today, although I'm not opposed to pulse testing my injectors. I don't what it was that was bad but one of those items must have needed addressing. I agree the fuel pressure is high but I'm also running 72lb injectors. I don't think that cam gives me much vacuum at idle either, and I need a better regulator, I'll order an Aeromotive regulator and plumb it back to the tank instead of the separator. Right now the pump is before the the separator, so the pressure is staying on the wrong side, I also think that's the reason I have surge at idle sometimes or it will stall and I have to give it half throttle to start it up again (like it's flooded).
So the running problem has disappeared but I'm running way too rich. The way it was programmed before the heads and cam, must have the map sensor dumping fuel to compensate for the amount of air that's in there. I still need the computer remapped by someone other than who I've used before.
Anybody have a person that I could talk to about remapping my ecm??

Hey Artic Friends (Smitty), send me a pm explaining what parts you have on your fuel system, where I can get them, and how I should plumb it to make it work.