Thread: issue after xp cam install?...

hey guys, so the ss is up and running with the new genv and xp cam set up....no leaks or anything that i can see or hear/feel..

after i put everything back together i decided to test it out and noticed that it seemed to be breaking up even with the stock 3.8 pulley on the gen v. seemed to notice it mostly around the upper rpm range of second gear.

a few days later i put my intense 3.4 mps on the gen v (since i will be getting tuned eventually) i got on it once just to see if the problem was worse and sure enough it was. its breaking up all over the place in first gear cutting in and out, feels like a combination of missfiring and fuel cut... and yes i have been super gentle on the car and babying it until i can get it on the dyno and see whats going on....

i really dont think i should be running out of fuel, i am on my old tune still that i had with my rocker set up and 3.4, but i know anything is possible....i was also thinking maybe spark blow out, or a possible bad wire/coilpack/plug wire... id like to see some of your guys feed back and opinions as to what you think it may be.

did a scan when i had the 3.8 on when it was breaking up and got 0 kr and was around 15-16* timing but i was only around 4k rpms in 2nd gear

Are you running stock plug wires?

what do you mean by breaking up?

also remember that when you are on the GenV the pulley size is .2 smaller, ei 3.4 on genV is actually like running a 3.2 on a gen3.

your tune is going to be completely different with the cam than it is with the rockers. you best bet is to put a stock tune on for now, then get your MAF and fuel trims inline.

fwiw im running 103's and a basiclly stock tune with no kr. not saying its a good thing just have gotten to tune it yet.

So you dropped in a cam and haven't disabled the multiple misfire P0300 code yet?

ok here goes, yes the plug wires are the same stock ones i was using with the 3.4 gen 3 rocker setup, and i am aware of the pulley difference between blowers, which is why i said i was surprised it was breaking up with the 3.8 on the gen v (same as a 3.6 on a gen 3)..no i have not disabled the missfire code as i was waiting to do everything at once on the dyno, worse case scenario is that i baby the car until i get it tuned...the car drives fine for every day regular driving just cant go wot.....and when i say breaking up i mean that if i go wot it hesitates and misses a little bit through out the rpm range almost as if it needs more fuel or like its just cutting in and out...i can take a video of it doing it and post it up, but i think its pretty self explaitory..

if you have easy access to the hp tuner then you should get the maf tuned or at least try a stock tune.

have checked your plugs?

yea i will have my tuner check it out hopefully since i dont have the actual hp tuner or software...and havent pulled the plugs yet, but when i put them back in they where fine, there the a 104s gapped around .055 if im not mistaken....its funny because my friend did a vs cam in his regal with the 3.4 and gen v and intense off the shelf pcm and his car rips with no problems...maybe the xp cam is just that much more aggressive

Another thing to add is sometimes my idle seems to be going nuts like a crazy cam lope, shoots up to 1500rpms then drops to like 500rpms then goes away and sometimes does again...def time for a tune and to find out what's going on, should be fun

that sounds like a vacuum leak...or a MAF problem...

Unplug maf and see if it idles better.

Checked all vacume lines and couldn't find anything..I just think the maff is out of whack and needs a tune...if it where a leak I would expect the problem to be consistent and not come and go. At this point I'm not really sure...maybe a ghost in my motor....

vac leak. scanning Idle air counts or looking at fuel trims would be helpfull

yea ill have to look into it...havent been able to find anything yet......if it is a vac leak it must be one of those weird ones that comes and goes since the idle isue isnt consistant.....i will find the issue though

i put my idle to stock and it was nice and smooth compare to the 900 rpms i had it set to.

unplug the maf and see if anything changes when the motor is surging. if nothing is different at all then likely have a bad maf sensor.