Car won't start and I missed out on racing!

[Brookgn]

I need Guru help!

I was driving home from testing Wednesday night. I made some good clean passes in preparation for some races Friday night. On the drive home the car started bucking,missing,and backfiring, at part throttle acceleration, especially when the converter locked.If you gave it throttle it cleared up. I parked it till Friday night. I went over to my shop Friday night.I changed my alternator because I got a new high amp one. I changed the cap on my cam sensor, because the old on had a crack and I thought that was the reason for the missing. Now the car won't really fire and run. It cranks, but it sputters and backfires. It only tries to fire when you give it gas but it just pops and bangs. Today I changed: the cam sensor cap,coil pack and module,chip,ECM,crank sensor. I looked at the TPS[.44v],battery[12.2v],coolant temp[93F],IAT[93F]. I checked all my grounds. I'm really at a loss now. The car was idling perfect when I shut it off on Wednesday. I didn't try to start it before I changed the alternator and cam sensor cap. I know I'm probably missing something simple. I'm open to any suggestions!!

 

[Dabigguy]

Try cleaning the mass air sensor. I had to use ether to fire it and it contaminated the mass air. Spurted some oxygen safe carb cleaner and she purrs now.

 

[Brookgn]

Thanks. I'll add that to my list of things to try tomorrow.

 

[86george]

I need Guru help!

I was driving home from testing Wednesday night. I made some good clean passes in preparation for some races Friday night. On the drive home the car started bucking,missing,and backfiring, at part throttle acceleration, especially when the converter locked.If you gave it throttle it cleared up. I parked it till Friday night. I went over to my shop Friday night.I changed my alternator because I got a new high amp one. I changed the cap on my cam sensor, because the old on had a crack and I thought that was the reason for the missing. Now the car won't really fire and run. It cranks, but it sputters and backfires. It only tries to fire when you give it gas but it just pops and bangs. Today I changed: the cam sensor cap,coil pack and module,chip,ECM,crank sensor. I looked at the TPS[.44v],battery[12.2v],coolant temp[93F],IAT[93F]. I checked all my grounds. I'm really at a loss now. The car was idling perfect when I shut it off on Wednesday. I didn't try to start it before I changed the alternator and cam sensor cap. I know I'm probably missing something simple. I'm open to any suggestions!!

If you didn't move the cam sensor to put the new cap on it should be ok. You have fuel and spark so the maf or hoses to tb could be the problem.To much oil on a k&n air filter can coat the maf sensor.Try unpluging the maf to see if anything changes.Check the air inlet hoses insides too.If all check out then it might be a timeing problem.Stock timeing sets were good at breaking teeth off.You didn't say what timeing set you have.Good luck

 

[Brookgn]

If you didn't move the cam sensor to put the new cap on it should be ok. You have fuel and spark so the maf or hoses to tb could be the problem.To much oil on a k&n air filter can coat the maf sensor.Try unpluging the maf to see if anything changes.Check the air inlet hoses insides too.If all check out then it might be a timeing problem.Stock timeing sets were good at breaking teeth off.You didn't say what timeing set you have.Good luck

I didn't move the cam sensor to change the cap. I have a AFE filter and I haven't oiled it since I got it. I have a T/A double roller timing chain. Thank you for the suggestions. I appreciate any ideas.

 

[TurboTerry87gn]

Check the cam position sensor, the index tab might have broke and moved position.
The car will run poor once the cam position disk moves, and it pops and back fires when it tries to restart because it dosent know where the #1 piston is.
What happens is the cam rod is driven up and the disk hits the cap and cracks the cap and shears the index tab off the disk.

 

[Brookgn]

Check the cam position sensor, the index tab might have broke and moved position.
The car will run poor once the cam position disk moves, and it pops and back fires when it tries to restart because it dosent know where the #1 piston is.
What happens is the cam rod is driven up and the disk hits the cap and cracks the cap and shears the index tab off the disk.

Please excuse my ignorance, but I don't know what you mean by index tab.

 

[TurboTerry87gn]

CamSensor

The tab that fits in the keyway of the shaft. Here is the repair kit with the new washer that has the tab on it.

 

[Brookgn]

Thank you! I will check that tomorrow.

 

[Brookgn]

Check the cam position sensor, the index tab might have broke and moved position.
The car will run poor once the cam position disk moves, and it pops and back fires when it tries to restart because it dosent know where the #1 piston is.
What happens is the cam rod is driven up and the disk hits the cap and cracks the cap and shears the index tab off the disk.

THANK YOU!
That was exactly what it was. I've never had that happen to me before. You saved me a lot of chasing my tale.The car started right up and ran fine. I also found the piece of the tab stuck to the cam sensor magnet. That's so tiny I'm amazed it's never happened to me before. I'm going to order the RJC one tomorrow. Once again thank you.

 

[TurboTerry87gn]

grad I could help.:biggrin: