97 Blazer HELP Please

I have a 97 Blazer 4.3V getting BAD gas mileage, and misfiring. I just got my code reader in today and I have a P0303 #3 cylinder misfire.

I just changed the following.

Air Filter - Fram
Plugs - AC Delco
Wires - Duralast
Distributor Cap - Duralast Gold
Rotor - Duralast Gold

I put a spark tester on #3 plug wire and was sparking fine.

Cleaned the MAF sensor with CRC MAF cleaner.

Double dosed the gas with Fuel injector cleaner and drove it about 45 miles so far.

Oil change 400 miles ago.

I had an overheating problem the other day when first started it would go up to around 220-230 before the thermostat would open - changed the radiator cap which solved that problem.

In the last month I have had the Catalytic converter go bad and replaced and the rear transmission seal go out and had it replaced and the transmission serviced at the same time.



I am at a loss, this thing is driving me nuts! and empting my wallet!

Any suggestions would be apreciated
Thanks

First make sure that the overheating was only the cap and hope you have changed that Dex cool every 3 years or so and are not loosing any coolant due to common lower intake leak. The misfire could (might) be the injector poppet sticking and you can try some strong fuel clener but normally it requires the upper intake be removed and each of the 6 injectors be cleaned by a GM procedure and then if that fails replace the bad injector - or just repace #3 or replace the whole system with the newer MFI for about $200 yourself. Search the posts for info on all that.

#3 is hard to get in and out, you might try pulling it out and see if the gap was accidently closed or gunked up with sludge while installing it the first time.

With a 1997, you will get these phantom misfires because of the ignition switch.

http://www.automotiveforums.com/vbulletin/showthread.php?t=287636

Well it isn't a phantom misfire on #3 it is misfiring, it is very noticable and if I pull the plug wire it makes no difference.

Does anyone know where the best place to get the MFI conversion kit?

Thanks
Jerry

Well it isn't a phantom misfire on #3 it is misfiring, it is very noticable and if I pull the plug wire it makes no difference.

Does anyone know where the best place to get the MFI conversion kit?

Thanks
Jerry

Grab another injector off of ebay and replace it.

They are cheap and can be easily swapped in to solve your problem.