Runs like crap in closed loop, great in open loop
Runs like crap in closed loop, great in open loop I have a 95 LT1 with an auto trans. The problem all of a sudden happened one day. It runs like it should in open loop, just fine, but when it runs in closed loop it runs like crap. At idle in closed loop, it smells really really rich, like your eyes water and you can smell gas in the car. Driving it, it won't maintain a constant speed, just keeps running slower (like it is way way too rich), then the SES light comes on and it goes into open loop, then it runs fine. It'll stay in open loop for a while, then the light will go off, and go back into closed loop, then run like crap again. This is a cycle, it'll stay in open loop for a while, then go back to closed looop. I looked at the code it gave me, it's right bank rich; which makes sense.
How this happened: I was going to school one day and got sick of going really slow behind some people. I floored it two separate times. It ran like it was supposed to then. The next time I started it and drove into town for lunch it started acting funny and has done it since.
Help me please diagnose this. Is it a stuck injector, faulty oxygen sensor, or fuel pressure regulator maybe? I'm an airplane mechanic by trade so I am not afraid to delve into technical things.
How this happened: I was going to school one day and got sick of going really slow behind some people. I floored it two separate times. It ran like it was supposed to then. The next time I started it and drove into town for lunch it started acting funny and has done it since.
Help me please diagnose this. Is it a stuck injector, faulty oxygen sensor, or fuel pressure regulator maybe? I'm an airplane mechanic by trade so I am not afraid to delve into technical things.
I have a 95 LT1 with an auto trans. The problem all of a sudden happened one day. It runs like it should in open loop, just fine, but when it runs in closed loop it runs like crap. At idle in closed loop, it smells really really rich, like your eyes water and you can smell gas in the car. Driving it, it won't maintain a constant speed, just keeps running slower (like it is way way too rich), then the SES light comes on and it goes into open loop, then it runs fine. It'll stay in open loop for a while, then the light will go off, and go back into closed loop, then run like crap again. This is a cycle, it'll stay in open loop for a while, then go back to closed looop. I looked at the code it gave me, it's right bank rich; which makes sense.
How this happened: I was going to school one day and got sick of going really slow behind some people. I floored it two separate times. It ran like it was supposed to then. The next time I started it and drove into town for lunch it started acting funny and has done it since.
Help me please diagnose this. Is it a stuck injector, faulty oxygen sensor, or fuel pressure regulator maybe? I'm an airplane mechanic by trade so I am not afraid to delve into technical things.
How this happened: I was going to school one day and got sick of going really slow behind some people. I floored it two separate times. It ran like it was supposed to then. The next time I started it and drove into town for lunch it started acting funny and has done it since.
Help me please diagnose this. Is it a stuck injector, faulty oxygen sensor, or fuel pressure regulator maybe? I'm an airplane mechanic by trade so I am not afraid to delve into technical things.
That was my initial thought too. Can I get by with cleaning them, or should I get a new one? I don't want to buy a new one and not have it fix the problem, I know those things are expensive. I am trying to get into tuning too, and I am pretty sure I'm supposed to have a wideband for that. What's a good suggestion for brands of wideband o2's?
You'll find a lot of posts here about the O2's and cleaning as it usually does not work. Get it scanned first and let us know what codes your throwing so we can see if it is indeed the 02's. FYI - you have 2 O2's (one pass and one driver side) both are before the cat. As to wideband do a seach as there is lots of posts on this subject.
I don't think I want to get a wideband after all. Next time I am with the car I'll see what codes it has, also I know how to check if the sensors are bad by the voltage they produce. I can check that too when I get a chance.
Trending Topics
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
On good O2s you will see a constant variation between 100-900mv. Most bad ones will have a more limited range or will get stuck around a certain reading, they will also not fluctuate correctly but tend to read the same thing over a long period.
It's ok now, the problem seemed to correct itself. I let it sit for a couple weeks because I had tests at school, went to fix it, but the problem never recurred. I bought an 02, but haven't had to use it yet.
Strange I know.
Strange I know.
Did you ever pull your o2 readings, Right now I am working on sorta the same issue.
In open loop The left is sitting at like 5oo-6oo mv and has a injector fault and the right side is at like 3oo-4oo mv with no fault . Take it out at at wot I have power but it is hoping in and out of closed loop like its scared of it.
Once mine hits closed loop it riches out and both jump to like 6oo-7oo and the car starts sputtering
In open loop The left is sitting at like 5oo-6oo mv and has a injector fault and the right side is at like 3oo-4oo mv with no fault . Take it out at at wot I have power but it is hoping in and out of closed loop like its scared of it.
Once mine hits closed loop it riches out and both jump to like 6oo-7oo and the car starts sputtering
