'96 Aurora engine miss

Hey guys, having some problems with my girlfriend's 96 Aurora. Engine has had a miss for sometime now... and i have tried just about everything I can think of. Scanned codes... showing Codes 300 multiple cylinder misfire, 301, and 303 misfire in #1 and #3. Replaced wires and plugs... as it was due with 40,000 on the last set, 93,000 total on the car. Still get codes 300, and 303. Did a compression check... everything checked out ok. Tested the coil pack and coil module, ok. I know you guys have said FPR is a big issue on these engines... I am gonna check that this weekend. Also am curious as to the anti-back fire valve that was mentioned in one of the late posts. A leak in the intake manifold/gasket was one of the things i was suspecting... and this would fall into line with that. Whats the best wasy to get to this valve/seal, and how hard is it to replace?? I am about at my wits end with this thing... and I just want to get it fixed. I Kinda doubt that its the EGR.... but I'll prolly check that when i do the FPR. I also know that there are screens in the fuel injectors....anyone know the best way to check/ clean them? If there is anything else you guys can think of

The correct AC Delco plugs and wires?

Packard Electric OEM wires and Bosch Platnum plugs

Stay with AC Delco plugs or you'll regret it (ditto on the wires, which you've done). I just paid $4.59 ea. for them yesterday from my local Bumper-to-Bumper, and installed them (along with the wires) last night.

Re: cleaning the fuel injectors, a buddy of mine has a kit that he hooks up that runs material through to flush the injectors. We did that as well and the car is running smoothly...

I too have read that the Northstar engine family are VERY picky when it comes to wires and plugs. I have read several posts of people having problems with engine miss while using Bosh Platinum plugs only to have it go away when using factory plugs. I have always used Bosh plugs in all my cars and have been VERY happy with them but when my 97 Aurora need wires and plugs I think Ill stick with AC Delco.

BKVic

What does a miss in the engine sound like. When driving on the Highway I sometimes hear one or two thumps from the enigne compartment. It used to be worse until I changed the plugs about 500 miles ago.

What does a miss in the engine sound like. When driving on the Highway I sometimes hear one or two thumps from the enigne compartment. It used to be worse until I changed the plugs about 500 miles ago.

Pull one of your plug wires off the front bank and take it for a quick drive. When you have a bad plug ,wire, or coil pack it usually wont miss all the time, sometimes only when the engine is under load but you will get an idea what the miss feels like and sounds like.


BKVic