my 01 protege check angine light has been coming on and flashing. when it does it sometimes won't go above 40mph up hills. according tothe repair shop the code is for "random cylinder misfire" but it wont act up so far while they have it. they suggested replacing the coil packs as a likely fix. i don't have much money to play guess and replace? any advice?

 

Pretty much same thing happened to me just a few weeks ago on my 02 Protege ES. At least i was getting a specific code (plug 2 misfire).
I replaced all four plugs just to be sure, both "jump" cables, nothing.
Finally got 2 new coil packs (approx $35/per) and that fixed it.

It was actually just the one coil pack sitting above plug 2 that was the problem.
If your coil packs are really rusty looking and the metal shims are flaking off they're probably going out.

You probably have 1 coil pack that is going out and is randomly miss-firing over the two plugs it distributes to, but I would recommend replacing both at the same time. That second pack can't be far behind the first. Might as well.

You could prob. get by replacing the 1 coil pack for now. I would inspect both and replace the one that looks the worst. Then if you've got a few bucks in a couple weeks get the other.

No need to replace the plugs, right now. I doubt that's the problem.

Coil packs are easy to replace, but here's a few tips I learned from my recent experience with this:

Disconnect your battery (this will clear the engine code)
Disconnect electrical connector cables using the release clip, and gently pull off the plug jumper.
WD-40 the two bolts that hold the pack to the engine before doing anything and let that soak in for a couple minutes (mine were really rusted... want to make sure you don't strip them, or break the heads off)

Take the screws out completely and set aside.
slowly start wiggling the coil pack back and forth, side to side.
Be gentle, and take your time getting them off. You may end up pulling them apart and then part of the cap/cable gets stuck to the spark plug (happened to me! lol)

Once the whole end is completely off, just make sure the new end of the coil pack has some dielectric grease in it. They usually come like this out of the box, but most part stores sell small indv. packs for a $1 each.

If you do end up getting some of the coil pack end stuck on a plug, You'll need to spend some time working that junk off of there. I used needle noise pliers, flat head screw drivers (for chopping the rubber grommet into peices), and some 8" tweezers. took me about 30 min just to get that crap off the spark plugs, and the whole install took about an hour. Would have been nice if it actually went smooth!

If you want or need to get the spark plugs out you'll need a longneck 5/8" socket (or metric equiv.), and an extender arm.

Lastly, once back on, and all the cables re-assembled test it out.
If the code comes back, and you still have a rough engine through a few revs, try doing the whole process again, but swapping the new pack to the other side (and putting the old one you took off, where the new one just was).

Make sure to dis-connect battery.

If code still comes back, and engine still feels rough, you'll need to replace both coil packs.

Hope that helps!
Good luck

 

thanks. replaced both coil packs. so far, so good.