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Help! Troubleshooting a dormant LS1


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Like a lot of projects out there, my car sits for long periods at a time. This last stretch of the sleeping monster had a few bouts of several months in a row without starting. The fuel in the car is more than a year old (I have the plastic camaro tank). I'm sure the fuel has water from season changes etc. So, I changed the fuel filter when the tank was nearly empty, added some fresh premium and a bottle of injector cleaner and started her up again.

 

THE SYMPTOMS: It still runs poorly. I get multiple random misfire codes and O2 sensor codes for both the rear O2's but they were supposed to be programed out, hmmm? When I lay into the throttle it is sluggish and I get a lot of raw gas smell.

 

Do I just keep running new fuel and injector cleaner through? Do I need new injectors? Do I need to pull the plugs and check them? I don't want to spend a bunch of money on this but I have run a few gallons through so far and it is not improving.

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O i forgot to mention this. For some damn reason O2 censers go out if they sit exposed to air for long periods of time. I had the same problem with my car a while back. Every 6 months i was going though O2's

 

They can also go bad if your car is running pig rich. Like 10:1 or more.

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Ok, I don't get any sensor issues. I get P0 147 lean bank 1 and PO 300 multiple/random misfire. Any ideas? Why would one side be lean? If it were an injector problem, wouldn't show up in the same cylinder each time, not random. Other than running injector cleaner, is there a good way to clean injectors if I pull the fuel rail?

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Sounds like it coild be a clog in the fuel rail on the one bank. I'd try blowing out the fuel rail and have the injectors sent to Witch Hunter to have them cleaned. One thing to remember when having injectors sent out to be cleaned is to install and run them within 30 days. If you don't, you run the risk of having them stick from the cleaning solution used. I waited about a year and 4 out of 6 were stuck. The 30 day recommendation is right on the reciept.:oops:

 

Joe

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To check if it is an injector problem find someone that is willing for you to remove there fuel rail and injectors and install them on your car. It is just 4 bolts, 8 connectors, and one fuel rail disconnect.

 

But if that doesn't work. Are you running O2 extensions? This is a problem very few people people have but it does happen. The voltage is dropping as it runs thought the extra length of the cable. I have read that the code can be turn off and the car should run like it used to.

 

P.s. check to see if it is the wiring has been burned or chewed up. This happened to me. a while ago.

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Ok, I solved some of the problem. I removed the fuel rail and pulled the injectors. I could not believe the amount of garbage in there. It was full of rust flakes from inside the fuel rail. When I originally put it on, it was from ebay, since the original was bent in an accident. I guess buying one that had been sitting for a while had a lot of rust in it. It has since flaked off. I thoroughly cleaned the rail. (I'll post a pic when I get home tonight)

 

I still get the misfire codes and lean on the left bank. I tried to blow out the feed side of the injectors where the rust had accumulated, but it obviously didn't work. I need to either find a better way to clean them, or get some new ones.

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Before they come in i would flush the fuel system. Drain tank, clean lines, and new fuel filter.

 

I am still in aww that there was rust in the fuel rail. My car sat for months an i never had a problem with the fuel system. I would just have 02s go out on me like it was going out of style.

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Machoir,

For something like this it's best to find someone near you with a tuning software like EFI Live or HP Tuner that can help you. With the tuner software you can see the activities of all the sensors live and you can see which cylinder is misfiring. This should help pin point the problem. Based on what you provided I am leaning toward dirty injectors. GL

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I wish you were local! I've seen your work. The Cobra is especially cool. There are a lot of shops around here that will do it for $$$. I just have to find some LS1 car guys that won't charge me an arm and a leg. Anybody have something like that in Dallas?

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My brother suggested the redneck injector test. Get a rectangle tub and pull the fuel rail. Leave everything hooked up but put it over the tub and crank the engine. I'm sure that will get messy. I just don't want the redneck injector test to turn into the redneck garage fire! Maybe I should pull the plug wires at the same time.

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I've been down this road before with my swap too so I know. When I finished my swap the car had a misfire on the passenger side bank and it had a huge back fire problem. After many days searching on LS1tech I found out I was not the only one with this problem and it seemed like no one can pin point the problem. After awhile I got fed up with it so I bought the tuning software and it helped me solved my problem. With the software it told me 2 cylinders were misfiring. So I went back to check the wiring for the coils and they were reversed on the passenger side. I swap the 2 coil signals at the PCM connectors and the problem solved.

 

I am still chasing the misfiring on my engine now but I know which cylinder is misfiring and the "counts". When I raised the rpm up a little the misfire goes away. One of my exhaust is not completely welded on so I think this might be my problem. Other than that I don't have any running issue with my swap. If I was close by I will give you a hand. It's really easy if someone already have the software on a lab top. It will take 5 mins to pin point which cylinder misfiring. From there you guess whether it's bad coil or clogged injector or bad O2 sensor.

 

Wait a minute I just remember something. All you need is the scan tool to do this. In order word you don't need a PCM license to do a scan. Only when you are tuning your PCM you will need a license. I wonder if I send you the software you can load it up to your lab top and you can use it?

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Vin. I do have a PCM reader, handheld. However, if your software gives a better read, I would appreciate it. My reader has been showing me the random misfire code (PO 300) and an occasional PO 302 code. Once it gave a PO 306, but I have not ever been able to replicate that. the other code is PO 174 for being too lean, left bank.

 

Goober, I hope I don't have that problem, because I have driven the car like this for probably 2 hours trying to sort things out. I should have some injectors next week. I will try swapping them out for cylinder 2 and 6 and see how I do. I may just swap all of them.

 

**EDIT** Aren't cylinders 2 and 6 on the right bank? Maybe I have a bad O2 sensor on the right and clogged injectors on the left. This is so confusing!

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Maichor,

Ah.. I remember now... The software alone won't do you any good. You will need the interface cable. This is what costs the most. The software you can get from any body. Sorry I can't be of any help. If you have lean condition on the driver side then I suggest start swapping O2 and then the injectors from side to side one at a time. Then check to see the problem moves. GL.

V.

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