99 z24/ 2.4 ld9. Experiencing a slight misfire issue between 700 and 2000 rpm. It never set off the CEL/MIL light, but I could hear a sputter in the exhaust note while idling in park and slightly giving it some gas. I decided to do the 2.2 ICM/Coil conversion. When I removed the IDI cover from the top of the engine the two inner plastic spark plug boot protectors stuck inside the spark plug wells and didn't just pull right out with the IDI/Coil housing assembly like the the other two. Of the two that did come out, one of them was visibly melted.
I tried pulling the boot protectors out by hand and they would not budge. I used a pair of pliers to pull them out they snapped into pieces. The coil housing itself looked new as if the previous owner of the vehicle had replaced the coil housing cover, but neglected to replace the boots and boot protectors/covers. I successfully installed the 2.2 ICM/Coil Packs from a 2000 cavalier 2200 SFI, However I still have yet to replace my spark plugs because If I pull them out with all that plastic junk in the spark plug wells it will fall inside the cylinders.
The ICM/Coil pack conversion did cure the misfire issue for the most part, However there is still a very slight sputter between 1200-2000 rpm while idling in park and giving it a little gas. I highly suspect that this is due to the fact that the spark plugs need to be replaced. I'm just trying to figure out how to get all that melted plastic junk out of the spark plug wells/holes without having to remove the cylinder head. Also, FYI : The engine has never been overheated and in fact is a salvaged low mileage engine with a "heat tab" still intact from the warranty period. Has anybody else experienced this coil housing/spark plug boot melting issue ?
The stock ld9 ignition system has to be the most asinine ignition system that I have ever seen on any vehicle in my entire life !
I cannot believe that these vehicles were allowed to roll off the assembly line with such a poorly designed ignition system ! Shame on GM ! After owning this 99 cavalier and two 99 3800 II camaros, It makes me want to stop buying GM products all together ! With issues such as the recalled ignition switches that could result in fire to the 1.5 million vehicles with the 3800 v6 that are at risk for engine compartment fires, It really makes me ashamed of GM.
If the pieces of melted plastic are loose enough and not melted to the side of the top of the block, just use compressed air and
blow them out. When you get it all out, then remove and replace the spark plugs. Doesn't sound like too big of a problem.
By the way, I owned a 1998 Z24 for 13 years and never had a problem with the IDI/Coil housing. Something had to happen to
that engine to create that much heat to melt the boots. I never had to replace the IDI/Coil housing, but there is a maintenance
schedule to replace the boots. I can't remember how often, but I do remember replacing mine at least twice because of regular
maintenance. Guess the previous owner didn't real good care of the car after all.
98 Z24
RIP Specks
*sigh* the LD9 igniton system is highly debatable. 99% of people will never have a problem and then others will install all new components and never get them to work. My old car was having issues, entire ignition system was replaced with no fix.. swapped to 2.2. ignition and the problem was solved. its hit and miss.
Have a nice day.
