misfire
#1
misfire
1996 cavalier 2.2 engine has a p0304 code. occurs when it goes into closed loop, have changed coils plugs wires injectors pcm checke wiring . can find no reason . any ideas
#2
Had the same issue
Check fuel pressure regulator, my cavalier had a misfire when i got it same cylinder 4 did ignition coil spark plug and fuel injector before i realised the fuel pressure regulator diaphragm was leaking. Its easy to check with a piece of tube and a hand held vacuum pump you can even borrow one from your local autozone. Through there loaner program. Just put down the deposit and get your money back when your done. If your close to your parts guy they may even let u use it in the parking lot.
#3
thanks its gone from bad to worse.foundbad module and fuel pump low on pressure.it has had all injector fuel pu,mp module and cooils plugs and wires cam and crank sensor fuel regulator tps and iac replaced. it now has a dead miss at idle cutting out no 1 and 4. number 1 shows misfire.had 150 lbs all cylinders 100 lbs running compression. driving it it will miss until you go past half throttlr then it runs with full power. all wiring appears good by testing ecm swapped out . nothing has cured it yer. right now it has 12 inches of snow on it.any ideas appreciated