98camaro28

iTrader: (21)

When I start my car, it seems fine. But after a while it'll bog way down and almost die and right after that it'll shoot up to 3000 and hover around and slowly come back down and repeat.. There is also some major tap in the valvetrain. I pulled the covers and all rocker arms are fine.

When driving, every 1/2 second to 2 seconds it feels like the incredible hulk has a chain on my rear end jerking me backwards. It is EXTREMELY hard to accelerate. It feels like it is almost missing but im not sure but my a/f ratio gauge is rather rich sometimes but can also go way lean. Also, my plugs and wires only have 2k on them.

There is vapor in my exhaust but I highly doubt its a head gasket or cracked head that would cause this. My car is just a bolt on car with 90k. I take very good care of my car. NEVER over-reved and ALWAYS change oil every 3k and ALL maintnance when it is supposed to be done.


I've had quite a few codes thrown and just haven't gotten around to delete them due to me having to re-tune shortly anyway. Here they are:

All o2 sensors are out from when I did my header swap
some evap code
Temp sensor high input
!EGR codes
!AIR codes
Knock sensor low input (its been that way for a year now and been fine)
Im pretty sure thats it.

PLEASE help me cause I can't drive my car like this!!!! It will be GREATLY appreciated!!!

GA95DCMSS

iTrader: (13)

Have you tried resetting the PCM to clear those codes?

98camaro28

iTrader: (21)

Yeah. I cleared them all last night and instantly bogged when i started it back up.

GA95DCMSS

iTrader: (13)

You say it has major tap in the valvetrain correct? Did you looked at the rocker arms, or did you physically check the torque on the bolts? If I remember correctly, a collapsed lifter could cause excessive tapping in the valvetrain. I could be wrong though.

Does your A/F Gauge show it rich or lean when it bogs?

What current mods are on your car? ( I take it just some bolt-ons?)

98camaro28

iTrader: (21)

Yes. All the bolts are torqued correctly.

Im not sure what it reads at the exact moment of bogging, but ill check later.

And yeah it is just your basic bolt on LS1. ALL stock internals.

GA95DCMSS

iTrader: (13)

All your O2 sensors are out as in bad, or just not plugged in? If your O2s are "bad" that could be causing your car to run rich, hence loss in power. Sorry for all the questions, just trying to narrow it down.

Braunbeck

iTrader: (4)

Did you scan the car for what the codes are?

It sounds like a possible vacuum leak in the system.

My car did the same thing when it had a leak at the EGR hole that was plugged in my old manifold.

5_02ls1

iTrader: (20)

check fuel pressure.....

GM WORLD CLASS

you can't determine much until you start fixing some of these problems. Without o2 sensors you PCM does not know how much fuel to add so it basically goes to limp home. Get those sensors in. U only need the 2 uppers for normal driving. Take care of all the p codes, leaving out emmisions if you want. It's gotta be air/fuel.

98camaro28

iTrader: (21)

They are plugged in. I figured the computer would just switch to open loop and not pay any attention to the o2s. Im not sure if it would actually do this or not, just an idea. Ill unplug them and see if it helps.

Im not sure if its a vacuum problem or not. I checked EVERYWHERE for a leak and the only thing i could come up with is a crack in the side of the evap solenoid next to the harness, which is why im guessing i have an evap code. But then again, its been cracked for a while now without any problems.

I've been trying to scrounge up some money for new o2s. What brand should I get? Do I need to get them from GM or would the NGKs work just as well??

98camaro28

iTrader: (21)

And what would be the easiest and most cost-efficient way to check my fuel pressure??

svede1212

iTrader: (3)

when your car goes to open loop you need to have your VE table spot on to get the correct fueling. i'd want to see a wideband O2 log and see what AFR i'm running. a vacuum leak is a good possibility too but without knowing your fueling it's a guess

98camaro28

iTrader: (21)

Ended up being moisture in my coil pack harness from when I rinsed the engine off... Very odd but I did learn a lesson!