99 Z falling on her face

**SteveCZ28** · 07-15-2009, 07:39 PM

Just recently my camaro has been throwing a fit....i dont know if i got into a bad batch of gas or what. but shes being tempermental and sneaky at the same time. when i take off from a dead stop get the car to about 1800-2000 rpm it acts like it wants to die..just falls flat on its face. acting like its starving for fuel or something. i have no clue, becuase it is not throwing codes at all...scan tool shows her running as happy as can be, but i know that she isnt...even if i start it in the morning or whenever for that matter and let it idle for a few minutes on its own, you can even hear it popping here and there like a definate miss...even watching the motor idling its like the motor has parkinsons disorder...just twitching all over the place and cant sit still to save her life..plugs only have about 10k on them along with wires...so doubt it could be that.....any help or recomendations would be helpful in my case...thanks in advance guys/gals

**V8MUSCLE** · 07-15-2009, 07:52 PM

mine has a "dead spot" around 2k rpms. it will pull so-so to around 1.8k drop off till 2k then pull like a mad man all the way up. mine idles pretty good but if its just started and i drive off(m6) whenever i shift it will pop on the way back down unless i stay on the gas through the shift. it sounds like gunfire outside the car.

**SteveCZ28** · 07-15-2009, 08:00 PM

yeah, mine does pull good/hard/normal after the dead spot....and if i let off it will kinda backfire or pop with the cut out open....but recently just did this. like with in the past 2 weeks. and im watching the gas mileage go to hell quicker than snot too..used to average about 350-375miles to a tank...it struggled to get 280 this last tank...which sucks hard

**35th-ANV-SS** · 07-15-2009, 08:18 PM

Engine misfiring can be several things; wires, plugs, faulty coil pack, catylatic converter, stuck/blocked EGR, O2 sensor, etc.

**SteveCZ28** · 07-15-2009, 08:21 PM

but wouldnt most of those items throw some sort of a code??

**35th-ANV-SS** · 07-15-2009, 08:28 PM

I would think so. ECM triggers the SES after only one instance. Sorry for saying this as it may seem just plain stupid, but is your SES light working? Do you see it come on when you turn the ignition key to the on position?

You said your engine is jumping all over the place? Does it idle bad?

Have you recently changed anything? Mods?

**SteveCZ28** · 07-15-2009, 08:36 PM

no ses light while driving..and yes ses comes on when key turned on...only change was i put in a e cutout about 2 weeks ago...the motor rocks all over the place, but does not idle bad...just the occasional pop or two every 2 minutes or so

**V8MUSCLE** · 07-15-2009, 08:53 PM

arnt cutouts are pretty much just like open headers?

**SteveCZ28** · 07-15-2009, 08:58 PM

pretty much, but i have my cutout basically right in front of my muffler...so its not like it can still suck all that air back easily

**silverWS6** · 07-15-2009, 10:00 PM

Mine was doing something like that a while back, and i checked my plugs and one was cracked... maybe check your plugs?

**0rion** · 07-15-2009, 10:53 PM

can you log mis-fire counts with your scan tool? That should narrow it to a cylinder for you. I'd look at plugs, wires, and injectors in that order.

**jaydean21849** · 07-16-2009, 03:47 AM

fuel filter or fuel pump

**Spaz** · 07-16-2009, 04:53 AM

same thing happened to me when my cats shit out on me... no SES no codes thrown untill finally the 02's went...

**SteveCZ28** · 07-16-2009, 07:00 AM

fuel filter is only about a year old...i was kinda thinking it was the cats too. cuz it actually seems like the car is getting quieter when i have the cut out open for some strange reason...might have to look into that...and how could i crack a spark plug when i dont go reaching around down in there?? and the scan tool isnt showing anything for coeds so i wouldnt even be able to get a mis fire log out of it

**silverWS6** · 07-16-2009, 11:31 AM

My spark plug cracked for no dam reason just one day it started acting funny with small popping noises in the exhaust and it would misfire and it was pretty bad... and idk why my plug cracked but you could see a picture of it in another thread I put "why would this happen?"

**SteveCZ28** · 07-24-2009, 01:50 PM

kind of an update here...thinking it still could be my cats as my air pump is running alot more than normal...even when the car is up to temp the pump will just randomly kick in and out...appraently trying tp ush air thru the cats, that may be clogging up?? any input?

**Hi-Po** · 07-24-2009, 02:39 PM

Get rid of the cats. If that doesnt work, Find someone with HPT tuners so you can log whats happening. Sounds like you have a basic scan tool. Have you looked really good at all your plug wires? Might sound like a pain to you but, pull the plugs. Start eliminating everything for sure.

**DaddySS** · 07-24-2009, 02:58 PM

A couple of thoughts:

Assuming this just started happening out of nowhere;
Reset the PCM
Pull the plugs and check them carefully (and the wires)
Replace the fuel filter
Check for any loose vacuum hoses or air leaks
Clean the MAF and make sure the wires are good and that they are tight on the MAF and the IAT sensor.

**SteveCZ28** · 07-24-2009, 06:44 PM

ill check plugs/wires tomorrow...maf was clean as of last week when i cleaned and oiled the k&n. along with wires wre good and tight....still think if it was something simple as that i would get a code. of which i am not.....random misfire from plugs would throw a code too.....im just clueless at this point

**maroca** · 07-25-2009, 12:06 AM

you probably have a problem with your o2 sensor sence you put a cut out in i bet this problem started right around the same time? thats my best guess man idk you would think it would set a engine light if so.