hey guys,

ok as we speek the new engine has 552 miles on it, so ok i told myself over and over through out the winter long 10 month rebuild process that i wouldnt take it over 4000rpm before the first 1000 miles or so, but what can i say i got boost happy..... i have been opening it up since the beginning of the start up, but me and my brother(a engineer for General Motors), think we are ok because we went with total seal (gapless) rings, and wiseco pistons.... i got 370cc RC Engineering injectors, along with Venom high flow rail, Accel adjustable FPR, and a vortech (adjustable) FMU... here is what happend, the car ran like a F***** raped ape the first 100 to 150 miles (this was all through wide open throttle a few times a day), and then, the 4th day after i started running it, i noticed that it had seem to lose some it felt like. the car still ran very strong though, by the 5th day or so, i check the compression: awesome 175lbs per cylinder, and no leak down. but this is the weird thing, the car will run like it used too every so often.... this is what happens, when i apply full throttle and it reaches about 8 pounds of boost, it seems to lug.. i look above my boost guage to the FP guage i have and she is bouncing from 60 to 80 lbs. of pressure back and fourth then it will quickly lower back down to 60 lbs. and run stronger as it lowers. it seems as if it will run better when i unhook the vortech fmu, and just let the Accel alone under boost, but then if i plug the fmu in along with the Accel, that is when it does this fuel pressure bounce effect. its really starting to piss me off cause i cannot stand an untuned motor... i have only been boosted a little over a year now guys, im still kinda learnen. i was just hoping that maybe even any of the turboed guys will have an idea of what to check out since it would be very similar since i am running the vortech blower (from RSM) which is centrifugal... but anyway, im hoping that maybe someone on here knows of any tricks that there is to these Accel regulaters when they are used with FMU's.... i am hooking up the LM-1 Wideband tomorrow, so that will help me a little, im kinda scared to see what kinda A/F Ratio numbers i am puting out now, cause its what ive been running my baby 2.4 litre 5,000 dollar charm on for the past week... "oh god"........ anyway, i will update what the air fuel ratios came out to be tomorrow nite hopefully, any comments as always will be greatly appreciated, im going to bed, but i wont sleep well until i have my boosted cavy tuned. but for the record, all u boosted j's, i did put a integra j-type away, and also an 05 Acura RSX-Type S "with a full Greddy cat-back system, and an Ingen cold-air intake (which by the way was all i could here when he was right behind my driver side window, them damn things redline at 8200 rpm's" its my good friends, i have to say they are pretty respectable, vtech is a wonderful thing of the four cylinder world... but anywho...... lets just say that the cavy smoked it..... i better end this and get some sleep, hope you guys can help me figure this thing out....thanks again...

ok firstly stop rambling

secondly, use the enter key more often cuz that was REALLY hard to read without wanting to skim

proper break in is VERY important during a rebuild going WOT right after start up after 10 months is pretty stupid. especially when you dumped 5000 into the engine

but onto your problem...

have you upgraded your fuel pump? if you have fuel issues, it might have just taken a @!#$ after the first 4 days of beating the hell out of the car.

I'd say check that first.

alright so you have upgraded your fuel pump....


if you're lugging I would say you're flooding the cylinder with too much fuel... although I don't have a boosted car but I thought it would be something simple....


definetly find out what those EGTs are.... maybe the FMU has a loose connection somewhere...

I bet you your running too rich.Im running 35# injectors,and when i dynoed my car,it was running pig rich.And thats with no fmu,just a s-afc.Get that wideband hooked up.Maybe you were running so rich that it clogged your cat.Maybe thats why your feeling a power loss.Unlikely,but you never know.But that was a mistake hooking up your blower when your breaking in a motor.When i rebuilt my motor i bolted in the charger,but i left the belt disconnected because i knew i couldnt break it in without hitting boost.Btw,what kind of fuel pump do you have?inline or intank?If its an inline,that can be your problem to.maybe your stock pump cant keep up.Good luck.


Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust

Sounds to me like he's going too rich. I bet he's in the 9's (a/f ratio)

There is such thing as too much fuel. Ideally in an FI car you want your af to be in the 11-13 range, keeping as close to 12 as possible (imo of course)

Personally, I think an FMU is the cheap way of doing fuel. I'd opt for a greddy emanage. I've never heard of your accel unit (haven't researched) but I'd see what your a/f is without the FMU. You might have plenty fuel without the FMU. Your FMU might be set wrong, upping fuel pressure too much, and maybe causing your computer to freak out, causing the switch in fuel pressures...

Get that wideband hooked up, we'll be able to give better speculation once we have better information

i think you need to get rid of the fmu and get a boost dependant afpr and set the pressure lower your over laoding the injectors i read max pressure for an inj to work is about 60-65 psi so as the others said your probably flooding the cylinders with gas . the inj cant open and close correctlly with 80 psi on them.


13's or blowning it. one way or the other!

hey guys,

yeah i am running the blazer (intake) pump.. i am positive its not fuel cut but i am leaning towards the same thing u guys are thinkin....too much freaking fuel. i have a few questions for you tuned boosted guys:

1. what are you guys running for fuel pressure at idle?
2. under boost?
3. do you think that i went too big with 370cc injectors if im only running 8lbs. of boost?
4. what type of plugs have u guys found that work well?, and what are you gapping them at?

i hope that someone can help me out with them questions. i am installing the wideband in the morning along with new plugs, and also doing a leak down test. wish me luck guys

Im running 30-35 psi at idle.Under boost,im not sure,i dont remember.i wanna say 50 psi.Those injectors are fine,you just have to have something to control them like a s-afc or something because you will run rich.Im using ac delco rapid fire #5 spark plugs gapped at 0.32.My s/c isnt hooked up right now because i think im getting blowby.I also have to do a leak down test.My compression test was good,200 on all 4,but i dont think the rings are sealing that great.hey,do you have oil coming out of your breather filter?If you rev your car in neutral,do you see light smoke coming out of the breather filter?Im trying to figure out whats wrong with my car before i do a leak down test.


Peter
'06 Cobalt ss/sc W/G85 Package
Gm Stage II W/2.79" Pulley
K&N Drop In Filter
Custom Magnaflow Dual Exhaust

no i dont have any oil coming out of my breather...... i am running total seal rings with wiseco pistons so blow by is not a problem..... however the cam housings are leaking for some reason. i am going to re tourque them today to see if it fix's them. i will update what i found with her later tonight.. thanks again guys