new AC Delco plug wires worsened problem

Recently I have been having a small problem with my 1990 lesabre engine missing/bucking once, usually while going up a hill, or under load. This may have happened on 3 out of 10 hills, and maybe one or two skips spaced several seconds apart. So, I concluded that I needed new plug wires, as the ones I had were installed 2 years ago, and were an off brand (put in by a nearby mechanic during a tune-up). So, I put some brand new AC Delco's in there, and driving home on the interstate last night, the original problem was amplified greatly. Now, I would say 6 of 10 hills (actually, even on flats) cause the engine to miss repeatedly and in quick succession, hesitating to much irritation until I let off the gas. Of course, it is difficult to drive properly this way, and reduces mileage, as cruise control can't be used, as the hesitation would continue constantly until the end of the incline. Is this some problem that I have created in somehow installing the new wires incorrectly? Maybe an ignition control module? I can't figure this out, as the old wires should have been worse than the new ones.

I would guess that the wires - new/old are not your problem. Have you tried cleaning/replacing the battery cables? These cars are known to get the yips when there's a buildup of too much resistance.

I'll check that out as soon as possible and post what I find.

Does this only happen on hills? If so I'd say you might have a fuel problem. Gravity not allowing fuel to your engine? Possibly a fuel injector is faulty or filthy.

I can't see why you would only have a problem going up hill with an electrical problem?


You may need to actually get this one checked out by a service person to find out the actual problem.

You might want to try to clean your fuel injectors with a fuel additive. I'm sorry if my post isn't helpful but I thought I would add the fuel component of the engine as a possible problem.

You're not getting a Service Engine light with this are you? The reason I ask is because I had the same exact problem. For me it was the crankshaft sensor going bad.

You're not getting a Service Engine light with this are you?

Well, not exactly. No code has been set that I can get via diagnostic mode using a jumper, but the CES light appears for a portion of a second every once in a while when the engine misses. Simultaneously, the speedometer needle jumps down 40 or 50 mph, then instantly returns to the correct speed. This might happen once every two weeks, and I drive ~600-700 mi./wk. This hasn't happened yet after I changed the plug wires, but then again I haven't had much time yet to test drive it around.

Just drove home from class, and the speedometer did its thing again. I was doing approx. 55, going downhill and speedometer whipped down to 10, then back, whilst my stereo cut off and subsequently came back on. This tells me there is some battery connection messing up (as yogi_123rd said above). Though it could be something else. If I can find what's shorting out or loose, it might be directly tied into the engine hesitation. But I still don't see how putting new wires would immediately make the problem worse, unless somehow one isn't seated against the spark plug post properly, or I hit a sensative wire somewhere.

Try checking your ground?

How well is your battery bolted down? Could it be moving against the frame>

Try checking your ground?

I finally had enough time inbetween rains today...removed + and - sideposts, and found the negative was in fine shape, but the positive was somewhat charred, apparently having overheated at one point. I've inspected both terminals about 6 months ago, and they were fine then. See posted image.

http://files.automotiveforums.com/gallery/watermark.php?file=/501/320270positive-cable.jpg


How well is your battery bolted down? Could it be moving against the frame?

I checked that everything was secure and my battery is definitely not moving around...good call though.

While I was inspecting, I noticed a frightful substance exuding from my ignition control module. It's green and quite sticky. Apparently this too has shown up fairly recently (within 6 months). It's like something melted on more than one occasion b/c there is newer and older green substance in various locales. It's dripping on my heater hoses and A/C compressor and harness. This looks very suspicious. Anyone ever seen this before??

http://files.automotiveforums.com/gallery/watermark.php?file=/503/320270dripping1.jpg

http://files.automotiveforums.com/gallery/watermark.php?file=/503/320270dripping2.jpg

Under ICM:
http://files.automotiveforums.com/gallery/watermark.php?file=/503/320270dripping3.jpg

I would remove the ignition module/coil assy and clean the grounded portion with some baking soda mixture the same as cleaning a battery connection
(try not to ruin the electronic connector in the process)check to see if a coil is melting down and if you see anything not to specs go to a junk yard and pick up another module/coil assy and install it.good luck

Took the coil/module assy. off today and separated the two halves. Here is what I found:

http://files.automotiveforums.com/gallery/watermark.php?file=/503/320270coil-and-module.jpg

Pretty messed up with all the melting. The question is, do I buy a new module and coil, or just the module? Why in the world would the module melt like this? This has happened only after I have owned the car, and I have never overheated the engine or driven harshly.

Also, checked the wire connections at the spark plugs. Found that the #6 plug wire was loose!! When installing, I pushed as hard as I could, and it seemed to go on all the way, but apparently it did not. I put the old wire on temporarily b/c the AC Delco (new) is coated in a nice whitish substance. For some reason, the old wire went right on and snapped on the plug stem, but the new AC Delco wire didn't. This definitely explains the uphill problem b/c the #6 plug is on the firewall side of the engine.

Wow, that looks pretty messed up. Somebody posted on this board about a month and a half ago and had the same thing happen. I think they decided it was the ignition console which I presume is the same as the ignition module. Green gunk was leaking out of it. I think those modules get fairly hot. That person couldn't even get the car started anymore. I believe I would start with replacing the module and try to use the coils. I have had problems with the #6 plug wire coming loose on my 97. Don't know why, but that one seems to work loose. It's kind of hard to get to on the back side. Good luck.

Well, I used the credit card and got a new module and coil asssembly and put them in. I had to really work on cleaning the harness connector that attaches to the module, with all that melted gunk in there. At any rate, the engine runs quite smoothly now. Haven't had any misfirings or stereo/speedometer problems yet. Hopefully the new module won't melt too. So, after all, it was an installation error on my part that the new plug wires seemed to worsen things. Though, I will be back to advance auto to replace that #6 wire for (hopefully) a better fitting one.