Need help! LS1 running poorly, experts needed!
10-28-2004, 11:28 PM
#1
Need help! LS1 running poorly, experts needed! I have an '02 Z28 with mods in sig below. Recently I had a little, uh, excursion off the road and the car spent 2 weeks in the body shop.
When I got it back, it intermittantly ran extremely bad, hardly at all actually. It would occassionally feel like only 1 or 2 cylinders were lit; the whole car would shake pretty bad (much worse than the cam lope); it wouldn't accelerate above 1,500 rpms; and it felt like it just wanted to die. Then it would snap right back to (close to) normal. I noticed that the engine had been steam cleaned and figured maybe water had gotten into the ignition or somewhere else and needed to dry out.
Fortunately, the really bad performance stopped after putting some miles on the car. However, it still seemed to be a little less spunky, and would sometimes ignite spent gas between high rpm shifts. Slight backfires I guess.
So I go to the track and I've lost over half a second and 5 mph. Definitely running like crap, and it wasn't the weather, clutch or traction, I am certain of that.
So what's the deal? Here are a couple of details:
Do I need new plugs, new O2 sensors, a new tune? Help! I need my power back!
When I got it back, it intermittantly ran extremely bad, hardly at all actually. It would occassionally feel like only 1 or 2 cylinders were lit; the whole car would shake pretty bad (much worse than the cam lope); it wouldn't accelerate above 1,500 rpms; and it felt like it just wanted to die. Then it would snap right back to (close to) normal. I noticed that the engine had been steam cleaned and figured maybe water had gotten into the ignition or somewhere else and needed to dry out.
Fortunately, the really bad performance stopped after putting some miles on the car. However, it still seemed to be a little less spunky, and would sometimes ignite spent gas between high rpm shifts. Slight backfires I guess.
So I go to the track and I've lost over half a second and 5 mph. Definitely running like crap, and it wasn't the weather, clutch or traction, I am certain of that.
So what's the deal? Here are a couple of details:
- current spark plugs are stock (29,000 miles) and have 12,000 miles on them since X1 cam install
- X1 cam was installed and PCM tuned by MTI one year and 12,000 miles ago
- car runs pretty rich at idle, I throw O2 codes a bunch
Do I need new plugs, new O2 sensors, a new tune? Help! I need my power back!
10-29-2004, 02:56 AM
#2
Do the cheap and easy tasks first.
Check all your plugs, clean them and check all your leads as well.
On another note I have heard of bad things from LS1's being hosed down as water gets under the manifold and can kill the knock sensors causing havoc if they give false knock. Just something to think about, find out exactly how they work and if water would effect them.
Check all your plugs, clean them and check all your leads as well.
On another note I have heard of bad things from LS1's being hosed down as water gets under the manifold and can kill the knock sensors causing havoc if they give false knock. Just something to think about, find out exactly how they work and if water would effect them.
10-30-2004, 03:44 PM
#4
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My car was doing something like that also and i unplugged the o2 sensors and it started running better. If the car is missing, find out witch bank it is and unplug that o2.
