wtf???
 

Ok so monday night i was driving my car, it was running perfectly fine, then i pull up to a stop light, light goes green and i cant go. i was having an insane amount of misfires in cylinder 1 and 3.. while this was happening my engine had a really rough idle (obviously) and i had no vacuum.. my uncle looked at it while it was doing this and he thought it may have been something to do with the computer (im still on the base tune for the sc build that vince sent me, after data logging he said my tune didnt need any tweeking) going into a safety mode or something like that, but no CELs were coming up other then the p0300 and the p0171 codes that ive been throwing for a bit but my car was running perfectly fine then... well i had my car towed back home and there it sat in my underground for the last couple days cause i thought i may have had a vacuum leak, today i went down to take a look at it and try to fix it, i got into my car and started it to see if it was still running really shitty, but it wasnt, it fired up perfectly fine and idled perfectly and i was in vacuum, so i took it for a drive and she ran fine, got into full boost perfectly fine too..... so what im trying to figure out is why my car would suddenly run like shit, then after sitting for a couple days be perfectly fine??? anyone have any ideas on what or if i should look for anything? i really dont need to get my car towed again

I wanna say drumrush was having a similar problem with his 2.2 sc build too? Might not hurt to ask if it's the same problem and how he fixed it.

k thanks, i just sent him a message on face book to come look here lol

loose wires some where? kind of an odd problem

well i went to the store for groceries and it happened again..... its def not a vacuum leak i have a video on my phone im uploading now.... im begging to think it may be a dirty maf im hoping, but your guys's input would be nice

I'll take a look at the video later, but my problem is slightly similar. When I stop at a light, my car sometimes misses and chugs and wants to stall, and it has stalled on me about 4 times. The codes I keep getting are P0300, P0170, and An oxygen sensor code (stuck lean). I'm pretty sure mine is just tune related.

maybe your fuel pumps are on there way out

Was it raining both times? Also are you running a CAI?

im running a CAI, and it does it raining or not

interesting when I had a supercharger on my 2.2 I had this problem, I never figured it out and eventauly gave up and went back to stock I'm interested to figure out what it is as well

mine isnt bad enough to justify going back to stock, not even close

U would think with so many ppl havin the same issue sum1 would no by now

bump!

Rain and snow, with a hydro shield, and CAI usually results in poor idle for me.

maybe it has something to do with the sensors did you guys compare builds? did u use stock map sensors?

How long has it bn since u guyz changed your fuel filters? I think it is also fuel related......perhaps the injectors or harness may be clogging up, and of course as mentioned before the fuel pump, I would also check all of the wires realted to the system as well

I'm going to run a big bottle of fuel injector cleaner through when I fill up next to see if it helps

what's the gap on ur spark plugs? maybe try something smaller. and u have an exhaust leak. I had the same. smaller gap and fixed my warped flanges.

I know I mesed around with a few diferent plug gaps but I had no luck with that. I was using the LSJtb and LSJ map wth IAT that bolts right up to the manifold with 42lb injectors I wouldent think it was the fuel pump because the ecotec build book says that our fuel pump is good till 300 hp but who knows maybe it could be a combination of dirty fuel filter preventing the fuel pump from supplying all the gas that is needed. any thoughts on that?

heres a thought.. are you all tuned by trifecta? or hpt?

i was tuned by trifecta

There is no exhaust leak. I was in the car when this happened both times

sounds like a fuel issue, running lean because not enough fuel too much air, back off a little bit with the SC. your fuel pump may not be able to keep up with the amount of air coming in. for your car to stumble and die then be fine days after sounds like you flooded it.

First of all, make sure you have no vacuum leaks. Then I'd check the wiring on you're throttle body, since you are running the LSJ TB when you spliced wires to make it work. Did you solder the wires or just twist them together? I was having a problem when I didn't solder my wires when I spliced them for the LSJ TB and if I hit a bump it move the wires just enough to send me into limp mode. Your issue sounds a little different though, but I'd still check it.