jclayc

iTrader: (8)

I've gotten my LS6 rebuilt with forged rods/pistons and added Trick Flow 220s and a 229/239 .627"/.621" 111.5+3 Comp Cam. I have a LS7 clutch, lightened RAM flywheel and a few other goodies like Kooks headers, a FAST 92 and a 90mm throttle body. I haven't gotten the car to the tuner yet and the car will run/drive but should I be surprised that it won't idle? Whenever it drops below 1000 RPM, it just konks out.

I have done the throttle body reset procedure and I'll also mention that I get some RPM surging when holding it above 1000 RPM.

NIKDSC5

iTrader: (10)

This is untuned? Stock injectors? I would suspect that many mods with out any corrective action to the ECU would cause all sorts of drive ability issues.

jclayc

iTrader: (8)

yes, untuned and with stock injectors... like I say, I know I definitely need a tune but wondered if it was abnormal that it wouldn't idle. (it goes like a scalded cat but I have to heel to toe the throttle at stop lights...)

would you recommend different injectors?

ryridesmotox

New injectors would require new scaling for the injector cycle and window generally. Its weird it won't idle. I have seen many other guys that claim an even larger cam not have issues. Have you pulled any ECU codes that may she'd some light? Are all your sensors hooked back up? Like you MAF, crank an cam position sensors, for example. Just shotgunning some ideas around here.

jclayc

iTrader: (8)

everything is hooked up

no engine lights/codes to pull

?from what I'm reading, it could be needing a tune to get more air or I could need new plugs (I'm running my old ones)

NIKDSC5

iTrader: (10)

Yeah you won't be able to run different injectors unless it is tuned. With that setup I would suspect you will be maxing out the stock injectors as is so...might be something to consider bringing with you to your tune/tuner. Ask them as they will know more. As for why it won't idle, I'm not sure. How long do you plan on driving it around before you get it tuned? I would check all sensors and grounds like ry said, as well as possible vacuum leaks.

NIKDSC5

iTrader: (10)

Some codes won't pop until a drive cycle is complete which will take a good bit of driving.

ryridesmotox

It will take a while for the light to come on. But a code reader with show codes that have not yet popped the light on, it will say- (immature) or something.

Recheck everything. It would be a million things. But vac leaks and sensors are where I would start.

ryridesmotox

Another thing. When you out the FAST on, did it seal properly? In my experience... It is easier to get a vac leak in an intake manifold seal than it is to get VD in a shady club in Bangkok.

jclayc

iTrader: (8)

I did put new intake seals on the FAST but it's always possible it didn't seat properly.

With the problems I had with a short , it may be that I still have an issue with a ground somewhere.

Perhaps I'll take the intake off this weekend so I have more room to look around at the wiring and check the intake's seating

punishmentcycle

iTrader: (6)

if you swapped a 78mm TB to a 90mm with out rescaling then thats prolly your problem. id get it to the tuner before you start taking it apart again.

jclayc

iTrader: (8)

I swapped in the FAST and 90mm throttle body a long time ago (before the heads/cam) and was running it w no apparent problem.

I'll plug into the OBD tonight and see what I get first.

NIKDSC5

iTrader: (10)

with no tune?! Man, I would love to see your pistons and rings. As well as know what your EGT's were! That baby was running lean!

jclayc

iTrader: (8)

After the heads/cam, all I've done without a tune is get it up to temp once at 1000 rpm, cooled, up to temp again at 2-2500 RPM, cooled and one drive around the block.

Steve01SS

iTrader: (43)

I wouldn't be surprised that it won't idle. My buddy did a cam in his car 224/228 and drove it for a week or 2. It barely idled and stalled all the time.

My C5 with heads and cam swap 234/242 ran like complete dick for the couple days before it was tuned. This was back in the day 2005-ish.