1 1\2 turns out on my FMU, about 73 pounds of fuel pressure under boost and it breaks up almost immediately when i go into boost. Warm wheather here, about 80+ degrees, but that should make it rich, right? 30 lb injectors, ATI say's 2-3 turns out on the FMU and i'm at 1 1\2....No black from being rich and later in the evening when it cooled down it pretty much stopped "breaking up", Popping,etc...under boost....
Hmmmmmm, running Autolite 104's i think, with .040 gap and some wires that need replacement.....I know i have burnt 2 wires, but it didn't start that untill the hot days.....
Any suggestions?
Thanks

 

Not sure how much boost you are running but try gapping the plugs to .035. You should definitely use a wide band to see where your a/f is if you haven't already and maybe retard the timing a few degrees.

Kris

 

Thank you....I will be replacing plugs and wires soon...$ issues. as always ...
Definately going over the valve covers too! I just thought if it's burnt wires, why did it clear up in the cooler temps?
Superchargers... It's a learning experience!
Yes, wideband readings would be very helpful, but i need it running right first....
Thanks for any input
John

 

Have you scanned your ar during normal driving?. if so i would do so just incase you see anything wrong there and work from there. What pulley combo are you running and ho wmany psi of boost are you trying to get out of it?.

 

I'm running a P600b pulley'd for 9 psi....I believe the problem may be the in tank pump.
I was just watching the FP gauge under boost when it was breaking up and i only saw 60 psi max...
The rail pressure won't hold, the intank pump valve must be bad.
It was breaking up under boost, so i kept increasing fuel pressure with no help.....
I had seen 73 psi as i originally said, but i quess it's all over for the intank pump....
Any other suggestions? I will change plugs and wires in the next couple days, these are the plugs i used at initial startup and 2 burnt wires too... 2500 miles now...
Thanks

 

If your car is not holding steady fuel pressure than your pump is the problem. Are you still running an FMU? What is your fp at idle?

 

IDOXLR8.....FP at idle is 42-43....When i turn the key on the intank and the Aux. pump kick on and shut off at 42 psi...Then the pressure drops to zero within 5-10 seconds....
Running the FMU with 30lb injectors and PCMFORLESS tuning....
Just breaks up as soon as you go into boost....Bettor at night when it's cooler, and doesn't seem to do it much closed loop.
(everything pig rich i assume)....
New MSD wires,plugs and over valve cover looms on the way, along with a new intank pump....Granatelli 255 lph....
Going in from the top through the hatch, i am not dropping the rear end!
I hope this solves the "teething" problems from this new setup, i want to go and get kicked off the track!....No roll bar....
Thanks
John

 

Sounds like classic ignition break-down.

Mine did exactly that until I installed an MSD box.

Mike

 

Thank you mike, i am running an Accel 300+ with the plugs gapped .040, so if it's ignition related, i would have to blame wires and plugs.
Didn't have this problem initially,Though it hasn't held rail pressure in a long time....(but who wants to change that damn pump)....
Hopefully it will be cured by throwing more money at it!...
Thanks

 

Well, i changed plugs and wires and it didn't change anything....
I will install the new in tank pump this weekend.
I tried running 1-3 turns out on the FMU, not a lot if differance, still just "stutters" and breaks up under boost....Could it be a MAP sensor issue?....When i start the car cold, the Autometer AF gauge holds steady just into the "rich" zone ( i equate this to "open" loop....During this time it ( i wait untill the temp comes up) it will run under boost without falling on it's face...After the AF gauge starts sweeping from "lean" to Just into "rich" (what i assume is the correct reading) and what i assume is the change to "closed" loop, it will fall on it's face under boost!!!!
This thing is making me crazy.....if 1 more punk in an Acura rolls up next to me and throws me a rev, and i can't just waste him.... Very frustrating, i'm NOT a street racer but i didn't Build a SC'd engine to have to pass up a challenge from some backwards hat wearing punk!
Any help or suggestions are appreciated....
John

 

Mine broke up under boost with new plugs and wires. When I installed an MSD 6A, later a Crane HI-6, the problem went away completely.

Mike

 

Thank you engineermike, i am running the Accel 300+, Shouldn't that be sufficient? MSD "superconductors" and NGK tr55's gapped .038.....
Acted the same with Moroso "blue Max's" and Autolite 106's....
I'm just confused, keep thinking it's the in tank pump since it won't "hold" rail pressure, and i can't rule it out untill i change it...
Odd that it more or less "goes away" at night when it's cooler, or "open" loop....Do i have those mixed up?..open and closed?
Thanks for the help, i do appreciate it!
John

 

Hi, How old is you opti? The cap and rotor may have allot of carbon tracking on it preventing full energy from reaching the plugs....under high load (You might want to pop the cap off to take peek at the cap and rotor) This will happen allot faster when using after-market high out ignition systems (msd , crane etc)

You could also give the Delteq system a try.... This will light off anything you can throw at it without the need for a MSD box. There is a group special going on right know.
http://web.camaross.com/forums/showt...hreadid=263358

 

Well hell.....I will install the new Granetelli in tank pump this weekend, but if that doesn't do it......
I quess after that my 30k mile old AC Delco opti spark is next...
Thanks

 

if all else fails take a peek under the cap of the opti to see what's going on ..... .


Jim