running ROUGH

[DavidT]

166,000 miles. Kirked at 80,000. Original coils as far as I know.
Well I have been getting a p1518 code for several months. If I goose the throttle before the car is warmed up, it will throw the code. The imrc cable seems to be working fine. This has been no big deal to deal with. BUT NOW I got a p0307 code. And running rough. I put a new coil pack on #7 cylinder Borg I think (OReilleys). The roughness changed a bit, but still there. Then another p0307 comes. So I swapped #7 coil with #8 coil. So far no code, but still running rough. You can hear the sound thru the exhaust. Car sounds "loopy". At highway speeds it isnt as noticeable. Sometimes it will run and sound fine, but within minutes it will act up again. So I am not sure if I got a bad coil or not. I also ran a can of SeaFoam in the tank. Wondering if the p1518 means way too much carbon and junk inside the engine... occasionally I think I can smell fuel... but not sure. I noticed today that the engine was not up to full operating temp. when it SHOULD have been. The needle was pointing to about 19 mph.
Anybody have any ideas? I was hoping to get another misfire code since swapping 2 coils... but not yet. I am tempted to order a set of ebay coils. But dont want to blow $.

 

[venom]

did you look at the plug on #7? Also the injector could be an issue. or lastly - check compression.

 

[DavidT]

yeah.... I changed out the plugs on the first bank... they all looked the same to me...

 

[venom]

yeah.... I changed out the plugs on the first bank... they all looked the same to me...

Certainly there is no need to go buy 8 new coils you have a persistent code for cylinder 7 that has come back after you replaced the coil (and spark plug) I assume when you say 1st bank you mean front bank, because cylinder 7 being in the front is actually bank 2.

It isn't common on the 96-98's but make sure the injector plug for cylinder 7 is on all the way, if your fingers are scrawny enough you can actually unplug the injector and plug it back in. In the 99's the little clips break easily the first time you remove them and the injector plugs may get bumped or possibly come loose. You should be able to reach back between the runners and get to the injector to make sure it is plugged on good. If your 307 comes back after swapping coils between 7 & 8 then i think you have fairly well ruled out that it isn't ignition, and it's time to move on to fuel or compression.

 

[luigisho]

If your 307 comes back after swapping coils between 7 & 8 then i think you have fairly well ruled out that it isn't ignition, and it's time to move on to fuel or compression.

Or signal to COP. Which is unlikely but possible.

 

[venom]

Or signal to COP. Which is unlikely but possible.

Valid point, and on that would have real merit on the back bank where the harness is known to melt down. Possible but less likely on the front bank.

 

[DavidT]

thanks for the input guys. The code hasn't returned yet. It returned ONE day AFTER installing brand new coil. SO... I took a gamble and ordered 8 new coils on ebay for $137. I have noticed for the last year or 2 a slight miss at 2k rpms cruising down the hiway at 55 mph. I kinda thought it to be a tranny issue... but searching for info here and at v8sho.com... it is a coil issue...so we will soon see!

 

[luigisho]

failing coils don't always throw a code. You could have more than one not performing correctly.