Little misfire

[Supreme Cutlass]

My car seems to have a small misfire, I thought this would fix itself after I drove the car for a while, but it's still there after a tune up, no codes. What might cause it? I'm running properly gapped delcos with new mag wires. could it be an injector problem?

*edit* Fuel filter is new too */edit*

[19Cutlass94]

Could be many things. Did you check the coil? I hate to say it but springs and that part of the valvetrain could cause it.

[trainman]

Check your coils...I had this same problem a few months ago. A quick look at the terminals....if there is any corrosion, they probably are going south, also check for small cracks on the plastic housing.

[Supreme Cutlass]

the coils visually look ok, no visible corrosion.

[92LuminaRS]

All of my luminas have a slight misfire to them at ide. I've accepted it as normal operation

[mihela816]

Sigh. :withstupid:

[94CutlassXtreme]

There are many things that could cause an intermittent miss. One of the best ways to help diagnose this would be to do a cylinder leakdown test on each cylinder. Basically, you bring the cylinder to be tested to top dead center compression (the time in which the intake and exhaust valves are both closed) Then you hook up an air line to the cylinder be threading it into the spark plug hole and read the gage. You don't want anymore than 20 percent leakage per cylinder and all cylinders should be within range of eachother. If excessive leakage is found, remove the air intake and open the TB, if you hear a hissing, then there;s a burnt, bent, broken, or overall improperly seating intake valve. Same thing goes for the exhaust. If not, remove the oil cap, if a hissing is heard there, then it means bad rings or leaking intake/head gaskets.

[chadz34]

Change the wires.

[chadz34]

:oops: Sorry you have new wires, my bad. The next would be the coil pack,fuel filter ,injectors. good luck.

[19902drlumina]

did u try an idle relearn after my tuneup it missfired and did the relearn and fixed it right up