Backfiring

[2fst4u]

Hi all...I have a question about my 1984 Grand National. I picked it up from a friends father..and he had 2 Grand Nationals..and worked on fixing one..and leaving the other sit. It's been sitting for about 2 years...and now that I have it...I have to work out all the kinks. First things first...it backfires when I start it up...and when I drive it loses power causing it to backfire out of the exhust and throtle camber. I've been told to check a few things out already...as I'm in the middle of changing the fuel pump...spark plugs and wires. I would love it if I could get as much feed back on this subject as possible. I do all my own work..and so far everyone I talk to has no idea and says Grand Nationals...specially 1984's are a royal pain to work on.

Well..thanking you all in advance for any help or suggestions you can make on this subject. Peace....

 

[JayLashua]

Spend $50 at a decent mechanic shop and see which fuel injector needs to be replaced

 

[JayLashua]

or you can also see if anyone you know has a 84/85 mod+coil pack you can swap out to see if it fixes the problem. But typically that sounds like a bad fuel injector (had the same problem.. would backfire and pop with 2 pounds of boost, and wouldnt go faster than 50 mph)

 

[2fst4u]

Injector....

Well...I had the car up to about 80 mph but it took some time...but once I got there it still sputterd and if I push the gas too hard it would still backfire. When I start off...and the car is in drive...it almost feels as if it's going to stall. Then...I have to baby the gas in order for it to move and if I hit down too hard on the gas pedal it starts to sputter and backfire all over again and I get a loss of power. Then it will catch...and it takes off but the boost climbs fast.

So from all the advice I've been given...I've been told several things. First...it could be the cam sensor. Second it could be the crank sensor. Third it could be the fuel injector or the coil pack. I'm replacing the fuel pump this weekend so we'll see if that helps. I'm also replacing the cam, crank sensor's and the coil pack. As well as my spark plug wires. So...with all this on my list I hope it works out the kinks. I'll keep you up to date, in the meantime...if you think of anything else it could be...please feel free to send feedback.

Thanking you all in advance....

 

[crazygn]

make sure all the injector plugs are on real good. I dont think its the cam or crank sensor being bad but you might want to set the cam senor, to make sure its not 180* out. Maybe pick up some new injectors or have them flowed and checked out from sitting one could be stuck.