checking spark
Thread Starter
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
checking spark
Hello, my 88 L98 is cutting out, missing, backfiring a little, and basically running like crap. It occurs at all speeds and most noticeably under load. My first instinct is a bad plug wire / spark plug. I changed them a couple of months ago and the car has been running fine until just a couple of days ago. I used an in-line spark plug tester and can see all plugs are getting spark. Can I rule out wires, plugs, cap, and rotor based on this or can they still be the culprit?
Thanks,
Ron
Oh yeah, car has 200,000+ miles and I normally drive it daily (but not with this problem). No SES light; I'm going to to check for codes anyway while I await your reply.
Thanks,
Ron
Oh yeah, car has 200,000+ miles and I normally drive it daily (but not with this problem). No SES light; I'm going to to check for codes anyway while I await your reply.
Thread Starter
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
One more thing to add
I thought of one more thing to add. The car was driving fine for about 10 miles on the way to work until I got onto the freeway on ramp. that's when it started missing and shaking. I was able to get turned around and drive it back home to switch cars. It now runs poorly at all speeds.
And there are no codes.
And there are no codes.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Check plug wires to be sure that they are secure on the plugs. Then wait until dark, lift clamshell, unplug hood lights and start car. Look for any arcing of the wires. They shouldn't if they are brand new, but worth the check.
Did you change the cap and rotor already about the same time as the wires?
Did you change the cap and rotor already about the same time as the wires?
Thread Starter
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
I just pulled all the plugs and checked them. They look fine, nothing wet or fouled. I'm going to change the cap and rotor next. gotta find something to mark the wires. I turned off the garage lights this morning and checked for arcing and didn't see anything. I'll try again tonight when it's darker.
Thread Starter
Racer
Joined: Sep 2001
Posts: 266
Likes: 7
From: Sumner WA
Well that seemed to do the trick. I'm surprised the spark plug checker lit up for all the plugs. I guess with 212,000 miles I always expect the worst. The thing is, when I replaced the plugs and wires I had purchased the cap and rotor as well. After fighting with the spark plugs, (especially #2 & 4), I looked at the cap and said screw it, maybe later. I took a test drive and it ran fine so I forgot about it. Had I changed them then, I could have been golfing today instead of wrenching! Oh well, maybe next time I won't be so lazy.
Ron
Ron
