Car is hesitating/w a backfire while building boost or just into boost

[Turbobuick#1035]

You have a cam sensor issue. Did you check the wheel? What kind of cap did you swap? If it’s a Casper’s, get rid of it.

Make sure the cam sensor wheel is not moving around. Make sure the tab on the wheel is not broke. Any play at all is a problem. Focus close on the cam sensor..
And put a stock cap back on it...

Just swapped the cam from a working car. Guess I’ll look further into cam

 

[Turbobuick#1035]

Do you get any KR when the problem happens ?? What are your O2 readings when it happens ? Also what plugs - ( part number )

No knock what so ever..02 number 5 6 780s..all looks normal.using NGK UR5

 

[Turbobuick#1035]

Just swapped the cam cap from a working car. Guess I’ll look further into cam

 

[OKBuickTurbo]

Boy, that really is starting to sound like the Crank sensor or Cam sensor. I recently had my crank sensor come loose and hit the interupter disk. The car stumbled and backfired, idle rpm went to 1400.

After I replaced the crank sensor, it idled fine but got alot KR with very little boost plus intake backfire. Crank sensor wasn't adjusted correctly and rubbed on the interupter. I also re-set the Cam Sensor and its back to normal.

I didn't get any codes either..crank sensor was $30. Cam sensor is more like $130. But first crawl under the car and see if the interupter is rubbing on the sensor. Put a breaker bar with 1-1/4 socket on the crank pully bolt. Rotate the engine and watch to see if there's contact. I hate to just replace parts willy nilly..$$$

From an old thread. https://www.turbobuick.com/threads/my-latest-prob.125339/#post-861397

 

[TurboBuRick]

Pull the cam sensor cap. Grab the wheel and turn right to left and up and down. Don’t just wiggle it. Grab it and try hard to turn it back and forth. If it moves, you found the problem. What you are describing is a classic condition of a broken tab on the cam sensor wheel or excessive up and down run out.

 

[Turbobuick#1035]

From an old thread. https://www.turbobuick.com/threads/my-latest-prob.125339/#post-861397

I will check for that. Done just about everything

 

[Gene Van Horn]

Mine had done this when when up pipe had come loose from the throttle body,i did alot of work until i found out it was loose. Easy check. It would run great till it needed more air.

 

[huntsg]

Tab in cam sensor as turboburick stated. If not that check to see if you have a cracked spark plug.


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[Turbobuick#1035]

Tab in cam sensor as turboburick stated. If not that check to see if you have a cracked spark plug.


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Replaced plugs ..only changed the cap on the cam sensor with another

 

[ScottHeidinger]

Have you tried putting the old plugs back in?


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[ScottHeidinger]

Did you take the cam sensor cap off to inspect the wheel for play?


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[Turbobuick#1035]

Did you take the cam sensor cap off to inspect the wheel for play?


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Just the cap..didn’t try the wheel for play

 

[ScottHeidinger]

Pull the cam sensor cap. Grab the wheel and turn right to left and up and down. Don’t just wiggle it. Grab it and try hard to turn it back and forth. If it moves, you found the problem. What you are describing is a classic condition of a broken tab on the cam sensor wheel or excessive up and down run out.

Try this. /\


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[captndave737]

After the car is running disconnect the cam sensor and see if it still happens.

 

[tford]

Mine did the same thing. Ended up being the cam sensor as others have mentioned.

 

[Terrance P. Perryman]

If the fuel pump has ever been replaced and a piece of rubber hose may have been installed check the hose clamps and condition of the hose.

 

[Chuck Leeper]

End play on the crank?

 

[ttypewhite]

Sounds like a PAC controller issue with the alky. Turn the alky off, turn the boost down, and put in another chip that runs with these injectors and get into some boost. Sounds like a alky issue to me. Either your pump is not pumping correctly, or it's not pumping at all.

 

[dank GN]

I had a similar issue that drove me crazy and it turned out to be the fuseable links connected to the starter. Basically when ever I got on it the the engine would touque over and the fuseable links that have lived by your hot ass headers for there entire life they would ground out and cause all sorts of weird stalling issues . at idle and cruising around they where fine it was only when the motor would torque over .So double check your main grounds on the back and front of the motor and the fuseable links attached to your starter keep us posted

 

[GNRick]

A dead spot on your tps sensor will cause a backfire. Happened to me.