John B

iTrader: (10)

I got the motor all put back together with the new B1 cam kit (courtesy of the MTI GP!) and I put on an LS6 intake while I was at it and an ASP crank pulley. Car fired right up <img src="gr_grin.gif" border="0"> and after holding the rev's up for a bit to splash more oil on the cam & lifters I let it idle for about 5-6 minutes (after having the PCM fuses pulled for a couple of days) to do an idle re-learn. Everything so far so good <img src="gr_grin.gif" border="0"> Even though I still have my stock exhaust with CATs the idle sounds very nice! At this point I do a quick oil & filter change.

I connect my ATAP and take the car out for a spin. The car seems to run just fine (obviously more power) except that I notice a significant amount of misfires at idle and running lean at WOT (0.830-0.870-ish). I brought the car home (after a good freeway WOT test thrashing & blowing the doors off of a yuppie driven BMW by 3 car lengths to 100mph that thought he was actually going to pass me on a two lane freeway on-ramp that merged into one lane <img src="gr_grin.gif" border="0"> ) and re-ATAP'd the car at just an idle for comparision to my previous logs prior to any swapping of components. I got idle misfires all over the place. Here are the interesting comparisons of data (1st set of numbers before swap) all at idle:

• misfires: 0 before vs. now every cylinder has an inadvertant misfire
• MAF Air Flow Rate (lb/min): avg 0.73 vs. 0.90
• MAP (Hg): avg 8.6 vs. 13.9
• Ave BPW Bank (ms): avg 2.81 vs. 3.52
• Idle speed: avg 800 vs. 800

And just as a data point, I have the PACE '02 LS6 Screenless MAF with my MAFT set at +10% rich base and -4% WOT (I didn't tweak anything here yet).

• Is it possible that I need to try and re-do the idle re-learn again?
• Could I have a potential vacuum leak?
• All of the plug wires are snug and the spark plugs have less than 1000 miles <img src="images/icons/confused.gif" border="0">
• The MAFT will obviously need tweaking but I wanted to solve the misfires first

I know that this cam is pretty much a bolt-in with no issues, especially since I have an T56. Please advise!

[ January 03, 2002: Message edited by: John B ]</p>

jmX

Sounds normal to me. I get 5-10 every "frame" before the computer resets the count. You know you'll have a problem cylinder if one goes up way more than the others. IE, if you have a spark plug wire disconnected you'll see the count get to over 100 before it resets.

Jon

StreetStalkerZ

iTrader: (1)

Welcome to the world of cams with stock tuning lol. You should get alot of misfires at idle because of the aggressive cam lobes the PCM thinks the car is stumbling and missing then starts to throw idle codes.

Your WOT o2s look lean and needs to be richen up some. I installed a set of NGK TR6s in mine to richen it up a tad (gap at 38) and if A tap still shows lean,if you have a ported MAF or descreened MAF put a stock one on until you get tuning. I would advise tuning as soon as you can after seeing how it changed my car to night and day difference in driving.

TA_2001

I get codes anytime I let it idle after a start.
After say 10 minutes of driving you dont get them
much unless you get stuck in traffic on a hot day.
Someday My SES light is going to burn out.

Terry

RPM WS6

iTrader: (3)

So what type of codes are you guys talking about? PO300s? I haven’t put in my B1 yet, but I had MTI tune the PCM already and they removed all that PO300 random misfire crap. Was there any other codes I should have had removed? Remember, I have an auto, so misfire codes can cause locking issues for me...

Trevor @ Texas Speed & Perf.

iTrader: (3)

[quote]Originally posted by RPM WS6:
<strong>So what type of codes are you guys talking about? PO300s? I haven’t put in my B1 yet, but I had MTI tune the PCM already and they removed all that PO300 random misfire crap. Was there any other codes I should have had removed? Remember, I have an auto, so misfire codes can cause locking issues for me...</strong><hr></blockquote>
You'll be fine. MTI also takes care of the lock/unlock converter issues that some people have. I didn't have any of those problems after MTI tuned the PCM in my T/A. You'll still show misfires if you watch them with AutoTap, but they won't set a code. <img src="gr_stretch.gif" border="0">

Nine Ball

iTrader: (38)

P0300 misfires are very common with any cams. You typically will set an SES light if you let the car idle too long for an extended period of time (a few minutes). To help prevent those "drive-thru-line misfires" just tap the throttle once in a while to change your throttle position readout.

Get crankin' on that MAF-T, no need to be running that lean if you have the ability to adjust it with the turn of a ****.

800 rpm idle might be a bit low, and will also cause more misfires. I put mine at 850 rpm by drilling out the t-body hole a bit more.

Tony

RPM WS6

iTrader: (3)

[quote]Originally posted by Trevor D:
<strong>
You'll be fine. MTI also takes care of the lock/unlock converter issues that some people have. I didn't have any of those problems after MTI tuned the PCM in my T/A. You'll still show misfires if you watch them with AutoTap, but they won't set a code. <img src="gr_stretch.gif" border="0"> </strong><hr></blockquote>

Thanks for the info and reassurance Trevor <img src="gr_stretch.gif" border="0"> I can’t wait till the cam goes in <img src="graemlins/burnout.gif" border="0" alt="[Burnout]" /> <img src="gr_stretch.gif" border="0">

Raughammer

Try just bumping up your idle just a "tad".

I bet it helps.

John B

iTrader: (10)

Whew! I thought that maybe I had some other issues going. I didn't even think to check for additional trouble codes since my SES light is still on based on my 5 other trouble codes from swapping the motor <img src="gr_images/icons/mad.gif" border="0"> (still waiting for LS1_Edit to delete these!) I checked this morning and did find the infamous P0300 in my trouble history so this makes sense now.

As for raising the idle speed a bit, will this be the easiest to do when LS1_Edit comes out (if it ever does <img src="gr_tounge.gif" border="0"> )?

Hopefully the pavement will dry up this afternoon so that I can fatten up the MAFT WOT settings and get in a few more WOT test miles before I head off to the dyno tomorrow <img src="gr_grin.gif" border="0">

Thanks everyone for the feedback.

Trevor @ Texas Speed & Perf.

iTrader: (3)

[quote]Originally posted by John B:
<strong>As for raising the idle speed a bit, will this be the easiest to do when LS1_Edit comes out (if it ever does <img src="gr_tounge.gif" border="0"> )?</strong><hr></blockquote>
You can either drill out the TB hole or just crack it open a hair w/ the set screw. It's easiest to adjust the screw (found on the pass. side of the TB) with the TB off of the car. I have my idle sitting at 700 w/ the blade cracked open.

Visceral

iTrader: (1)

I have the B1 in my Vette.

MTI wrote up a computer for me that rasied the idle to 900 and raised the random-missfire code threshold.

No codes, ever. On my SS< I always get the SES normal Missfire codes after a day or two. I can deal with the SS's SES light. I run a 112 ls cam (Hammer) in there anyways, and autotap it all the time. The C5's have this really annoying habit of spilling all the codes to the info-center AS WELL as sending out the SES light. SO I paid to have MTI rewrite the computer, even though I have the B1. I dont have a MAFT on the car though, which I probably should.
Probably half or more of the folks on this board with cams just put up with the SES light. THe other half paid 500$ for the computer to be rewritten. We all cant wait for LS1Edit to be released <img src="gr_stretch.gif" border="0">

chris