as some of you know i just finished my cam install but exhaust has yet to be installed (appointment tomorrow) i haven't run the car much other than few starts and then around the block a few times. the car was stumbling really bad then i replaced a buster knock sensor it didn't seem to help much but i didn't figure that was the cause anyway it just needed to be fixed anyways. i also found and repaired a vacuum leak which seemed to help a good bit but not perfect im hoping the rest of the problem is just bad o2 readings because the exhaust isn't installed.

im trying to think of the symptoms of bad o2 readings correct me if im wrong but it would be ok in open loop but as soon as the car enters closed loop it should begin to stumble and hesitate because of incorrect fuel trims due to false o2 readings right?


also if any of you have driven your car with open headers how did the car behave?

 

Why don't you give us some indication of your setup. I would initially probably say that the PCM is not tuned to the cam but am not sure and definitely have nothing to go on.

Is it stumbling or surging?

 

sorry. I installed the gm847 cam and the basic bolt ons. the pcm is a mailorder tune from madz28 and i don't think the tune is the problem i do have a check engine light but don't have access to a scanner but i will run by the shop tomorrow to check the codes.

 

fouled plug problem fixed

 

my car ran like complete crap with open headers because the sensors manage to read the open air to some degree.

 

I agree with JoeliusZ28.

open headers will make it run like CRAP.

The open going back to O2's really freak out the O2's and they think it is LEAN so they steadily dump fuel and try to correct.

This is the way my ONLY open headered LT1 ran and after installing the exhaust, it was fixed (other than replacing the dead plugs).

All the extra gas is not too cool for cylinder walls, bearings, etc.

Lloyd

 

ya i knew that the o2s would get tons of false air but what made me think something else was wrong was it would run like crap right after a cold start when i assume the car was in open loop.

to give you the complete rundown of what happened the i limped the car to the exhaust shop yesterday so i could rule out the o2s and when leaving i still noticed the miss so i parked the car and remembered that i had an injector that wasn't plugged up properly two nights ago so i pulled that plug and found that the plug was fouled so i replaced it and the car the car runs perfectly now.

now its just time to enjoy the car and save up so i can do some business with you lloyd a set of your LE2s are next on my list but ill have to pick up some different castings since my 97's are to thin