Help - Cylinder 1 misfire P0301
 

Hello - have a 1998 chevy blazer (actually it's my son's) and trying to fix it for him while he is in Marine bootcamp. Put it on the diagnostic and received a P0301 code. Know for sure it's cylinder 1 - have replaced cap/rotor, plug/wire. What next? Thank you

Tell your son thanks for helping keep our country safe!!!

Check compression on all the cylinders and compare....might also try a fuel injector cleaner or seafoam the engine if the compression test is good. Also, check for injector pulse...you can rent a noid light at auto zone....install it on the injector plug and have someone crank the engine to see if the noid is lighting up...if so your getting injector pulse...might be a bad injector.

If no pulse check your wiring.

What kind of plugs/wires did you use???

Thank you FROG - We used Champion Platinum plugs. Will take the next steps you've suggested. Thanks again

Hello - We gave up and took it to a mechanic, however, didn't have the work done, since they were charging twice for everything. Mechanic said it was a fuel sprayer/spider injector. We know it is only happening for cylinder 1. Couple questions:
1. Can you replace just 1 fuel sprayer in a spider injector/throttle body system 2. Is it unlikely that a professional fuel system cleaning would resolve this issue? 3. Anyone know a good video resource to change the injector?

Thanks so much for any help. Son graduates marine bootcamp soon and we are trying to get his car fixed for him.

1. You can, but any more than that and it is more cost effective to replace the whole spider with the updated MFI spider.
2. It is worth a try before cracking open the plenum.
3. I haven't seen one...

If you do end up getting in there and replacing either one injector or upgrading to the MFI spider, do not take the short cut of bending the fuel lines out of the way. You will have a heck of a time getting them back into the spider body if you just bend them out of the way. Disconnect them at the firewall and pull the whole line assembly off the motor.