no spark, ...bad coil???

[TheorenIII]

Hey there, been using this site for a while now with great success (this place is awesome, especially for someone like me with limited car knowledge), but this is my first post. I have to be inspected on Mon morning (it's Sat afternoon now) and will fail with my CEL. Went to a few mechs who gave me differing codes. The last guy I talked to said all the codes are related, but just symptoms and the real cause is no spark somewhere in the ignition system. Showed me where there wasn't a spark jumping from the coil to the plug wire on cyl 4. I needed the car for work, so I left and replaced the wire and spark plug after work and still no spark. All the others are fine. Would the coil be the next place to try? What's a good way to test it? Also, is it necessary to replace both at the same time? I would appreciate any help or suggestions. I'm trying to get this fixed fast and cheap (and have to work today, Sun, and Mon) Thanks in advance and thank you to all the others who have taught me so much in the last two years without ever realizing it.

 

[TheorenIII]

and the hush was deafening...

just as a follow up, I decided to get the ignition coil just before Autozone closed. I installed (the last one they had) and I got a spark!!! Also, replaced the gasket on my gas cap, cleaned the MAF, got a better seal on the evaporative emission return tube, and replaced the camshaft position sensor (CMP). Don't know which had the greatest effect or if it was a combination of everything, but my MPG went up to 13.5, better than the 7.5 I've been averaging for over a year. I still have the CEL, but feel like now I'm on the right track.

About the CMP, I decided to replace it even though I had suspected the code was a one time thing and maybe a false reading. But, since I already had it and finally found where it belongs under the coil, I went for it. The old one was in bits! The inside was rusted and totally shattered, the magnet and plastic lodged in the camshaft. Didn't think it was so hostile in there.

 

[old mechanic]

Glad you found the problem. The coil would have been my guess too.
Wow! 7.5 mpg? That was really bad mileage. Big improvement.

 

[TheorenIII]

It is bad, but I had accepted it. I do a lot of deliveries in a town with a stop sign on every corner.

 

[TheorenIII]

Quick update... CEL came back, checked w/ Autozone, only had one code (down from 14)...P1400. Knew what to ask for from reading so many posts here. Asked for the DPFE (or EGR pressure sensor, as they call it at AZ). Swapped it out, no more code for the 1st time in three years. Took about 2 dozem short trips tonight, light has stayed off. Just need to pass the inspection tomorrow...

 

[TheorenIII]

In conclusion...

it passed the emissions test! Not only will I start saving on the amount of gas I spend but, by getting the inspection sticker in time, I was able to avoid a $120 ticket (dismissed Mon night) and by doing the work myself saved a lot more. The parts I bought totalled $95 (coil and DPFE) while a mechanic in town gave me an estimate for "$400- 500. Another happy ending!