I have a shutter at Idle that is intermitent. I only happens when it is cold(at idle) or has been shut off for an hour or so. It has given a "random misfire" code once. The mis goes away after driving for a couple of miles. When this occurs the A/F meter shows dead lean, so lean that the lights won't even light up until I give it some gas. The A/F ratio will even show lean when driving and won't get in the green (rich) when I mash into it. When it goes into Lean/rich mode while cruising the gauge will only cycle from lean to stochiometric. Sometimes it will slowly creep torward rich the more I drive it(after 10-20 miles). And on the other hand, sometimes it will crank cold and run fine and show normal on the A/F meter. This has been occuring for a month, basically as long as I've had it. I checked the plugs due to the extra boost and worried there might have been some detonation occur, but they checked out ok. I now have 2000 miles on the system. Intermitent problems suck!

Help!

 

Let me get this right, you are running 11.5 psi on a 4.8 with a stock Radix tune??

 

Thats alot of damn boost out of a radix I bet that when its running right that thing gets up and hauls.

 

Yeah. You read that right. That is in 95+ degree Alabama heat and 93 octane. I put the Royal Purple's version of Water Wetter in the intercooler. Maybe that helps? I just put a 160 deg t-stat in it yesturday. I have had no problems other than the above stated. I can barely hear a little valve rattle when pulling up a hill like any vehicle does. I'm going to have a custom tune done as soon as I get some headers on it.

I forgot to mention that I cleaned the Mass Air sensor with Electric parts cleaner yesturday and it acted up this morning when I cranked it and the entire way to work. It runs and drives fine after it warms up a little, even when the A/F meter is reading lean.

 

1slow01Z71...I saw in another post that you are working at Browns Ferry Nuclear. Well so do I. I'm an AUO in Operations. Look for the black Joe Gibbs in the parking lot. I'm on day shift this week.

 

if you keep running that truck lean ur gonna have some major probs. u need some 44pounders, 255 hp pump and a dyno tune!!!

 

The magnacharger comes with bigger injectors and fuel pump . I think they are 44lbs and I'm not sure about the pump. It is either a 190 or a 255 lph. The lean issue isn't constant. I don't romp on it when it is leaning out. The lean issue is constant when it is acting up, but that is only 50% of the time. When it isn't acting up it is full rich when at WOT. Whe n it is acting up it is lean all the way across the board no matter what throttle position or rpm.

I'm thinking maybe bad O2's. I did put a bottle of 104+ octane booster in it when I first installed it due to having a half a tank of 89 gas. It was a bottle that has been on the shelf of my shop for a few years and I'm not sure if it was O2 safe. It seems like the O2's get more heat in them it starts to straighten its self out a little. It never does it completely while driving though. It may do just fine when I crank it tomorrow morning and be ok half the day.

Sorry to be so long winded just trying to give as much info as possible. Any of you tuners have a hunch?

 

i think what he was getting at is that its probably not the best idea to be running a smaller pulley without a proper tune for that pulley.

be careful not to blow the motor.

 

sounds like your intake gaskets are leaking at the bottom of the radix.
these gaskets are garbage. i replace a set a week on regular trucks at work.
same symptoms and no added pressure. make sure they are the updated green rubber in black plastic. check torque again also.

 

how do you figure the are junk? I have had them for 25K on this truck and 75K on my old one.