HELP! Car wont start...
Thread Starter
TECH Apprentice
Joined: Jan 2004
Posts: 380
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From: San Antonio, Texas
HELP! Car wont start... Okay so I was comming home from work and I noticed my accelaration went to ****... like I lost a **** load of power. When I would punch it it wouldnt go anywhere it would just barely pull. It was hard enough for me to get on the highway. So I stopped at autozone since my car was throwing 3 codes, p0121 Throttle Position Sensor/Switch A Circuit Range/Performance Problem , p0153 02 Sensor Circuit Slow Response (Bank 2 Sensor 1),p0155 02 Sensor Circuit Slow Response (Bank 2 Sensor 1).
At autozone I bought 6 quarts of mobile 1 synthetic, mobil 1 oil filter, 8 bosch platinum spark plugs, and a plug gapper. My new forged 347 has 2000 miles on it so I am now am switching to synthetic. My friend let me have his two back 02 sensors, cause he got a x pipe, to replace my bad ones.
Well I get home and start changing the oil, the oil is pitch black. Then I start changing the spark plugs. When I get to the number 2 cylinder the spark plug was full of gunk and oil. All the rest were just a tad bit brownish with no oil. Then I replaced the front o2s.
So after all this was done I try to start it but it wouldn't fire up at all, it just cranks over and over. I've rechecked all my spark plug wires for a good connection, checked all the fuses, and still no luck. It almost like I am not getting any spark at all. What are some of the things that would prevent a ls1 from starting up blown headgasket or something internal? PLEASE HELP!!
At autozone I bought 6 quarts of mobile 1 synthetic, mobil 1 oil filter, 8 bosch platinum spark plugs, and a plug gapper. My new forged 347 has 2000 miles on it so I am now am switching to synthetic. My friend let me have his two back 02 sensors, cause he got a x pipe, to replace my bad ones.
Well I get home and start changing the oil, the oil is pitch black. Then I start changing the spark plugs. When I get to the number 2 cylinder the spark plug was full of gunk and oil. All the rest were just a tad bit brownish with no oil. Then I replaced the front o2s.
So after all this was done I try to start it but it wouldn't fire up at all, it just cranks over and over. I've rechecked all my spark plug wires for a good connection, checked all the fuses, and still no luck. It almost like I am not getting any spark at all. What are some of the things that would prevent a ls1 from starting up blown headgasket or something internal? PLEASE HELP!!
TECH Addict
Joined: Dec 2001
Posts: 2,907
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From: Bergen County, NJ
Start with the basics- are you getting spark? Pull a plug wire and hold it a 1/8 inch from ground while you crank it. Are you getting fuel? Can you hear the fuel pump when the ign is switched on? If you press the pressure release at the end of the rail do you get gas?
Teching In
Joined: Nov 2006
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Originally Posted by ws.6kid
Well I get home and start changing the oil, the oil is pitch black. Then I start changing the spark plugs. When I get to the number 2 cylinder the spark plug was full of gunk and oil. All the rest were just a tad bit brownish with no oil. Then I replaced the front o2s.
Ign. relay makes sense if the engine is turning over but not starting. Certainly code related. Good luck!
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Thread Starter
TECH Apprentice
Joined: Jan 2004
Posts: 380
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From: San Antonio, Texas
Originally Posted by aSSasin
Double check the spark plugs. There may be fuel buildup on them instead of oil, or a mix of both. I've seen this before. This is caused by a bad air/fuel ratio (since your O2s were bad). If your car was tuned then it could be a factor, especially if you had bad O2s on there during the tune. If you replace the plugs that doesn't necessarily mean more fuel won't leak and build up. Eventually, you'd end up washing out the piston rings. While this may not be your problem, since your codes are all electrical, be sure to check on it if you get your car started. Something small like that could really mess things up and cause you to start over.
Ign. relay makes sense if the engine is turning over but not starting. Certainly code related. Good luck!
Ign. relay makes sense if the engine is turning over but not starting. Certainly code related. Good luck!
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Thread Starter
TECH Apprentice
Joined: Jan 2004
Posts: 380
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From: San Antonio, Texas
Well I changed my fuel filter, replaced the fuel pump relay, and checked for fuel in the fuel rails which there was. I can hear my fuel pump prime when I turn the key so, the fuel pump seems to be working ok. It's still not starting up. 
Im leaning more towards a spark issue if anything else. Bad coils maybe???
If anyone has any other suggestions please post them....
Im leaning more towards a spark issue if anything else. Bad coils maybe???
If anyone has any other suggestions please post them....
I'm not sure how F-bodies are setup, but on my C5 the ground for both coils is on the back of the driver's side head. If this wire is disconnected/broken the coils will not fire. Ask me how I know 
Thread Starter
TECH Apprentice
Joined: Jan 2004
Posts: 380
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From: San Antonio, Texas
Ive already checked the grounds in back of the drivers side head. Everything seems fine. While I was searching I cam across someone who had a similar problem as me. He said something about a bad alternator wire from the pcm to the alternator and he unplugged it and it started? 
Does auto zone or any other store sell a spark tester? I still think im not getting spark cause I know I'm getting fuel....
Does auto zone or any other store sell a spark tester? I still think im not getting spark cause I know I'm getting fuel....