Chasing a lean spike

[Mike T]

Literally just pulled this one out. #2 since it's so easy. About 300 on it now and it is a light grey as far down as I can see.

 

[Mike T]

Come to think of it that plug was only driven about 1/2 of a mile after being run hard. Should be a good reference.

 

[No disintegrations]

 

[No disintegrations]

This is a good chart to go by. It's hard for us to tell the whole story from pix. Use fresh plugs with a only a handful of miles on them. Wot then shut it down and pull them all keeping track of where they're from.

 

[Mike T]

Ok some really crazy stuff happening in this log. Was pulling decent you will notice that fuel pressure went to 0 in frame 122 (no way). Then if you review frame 183 through 187 you will see rpm drop to 700 (from 5150) and timing go to 27.5 degrees (guess because the ecm thinks the car is at idle) and of course next came the intake backfire spiking the manifold pressure.

You will have to review in gauges to see all of this happening.

 

[Chuck Leeper]

Just my $.02.....Plugs should be fresh, WOT pull, and a clean cut.
Once that's done, the threaded portion is cut off, to inspect the fuel ring.
I don't use never seize on a plug I'm going to be changing frequently/ or looking for a reading.
Short of cutting the thread, use of an otoscope is a reasonable way to look into the porcelain..

Back under my 55.

 

[Mike T]

Just my $.02.....Plugs should be fresh, WOT pull, and a clean cut.
Once that's done, the threaded portion is cut off, to inspect the fuel ring.
I don't use never seize on a plug I'm going to be changing frequently/ or looking for a reading.
Short of cutting the thread, use of an otoscope is a reasonable way to look into the porcelain..

Back under my 55.

I know the basics but definitely need to learn more in this area.

After checking cam sensor shaft play and replacing sensor cap without improvement......I think we found the problem.....maybe.

While at idle I started pulling plug wires at the coil. First 2 pairs would throw a blue spark about 2 inches but 1-4 was red/blue in color and would not arc until plug wire was 1/2 from the coil post.


What chain store has a decent coil? Just going to run it for a while and move on to the tr6.

Autozone, O'Rilleys, Napa and Advanced are my local choices.

Thanks again.

 

[Chuck Leeper]

I bought 3 coils from Advance, to get 1 good one. I had a new OEM module, and took it with me, hooked up my Caspers tester, and showed the clerk what was going on. Did this til I got a good coil pak.
Without testing, it's a crap shoot.
All the ap stores are going to sell you the same stuff. Take your choice. Most have "lifetime" warrantees.
Doing it again, I'd go straight to TR6.
FWIW, the truck coils on my turbo LS, will knock your pacemaker offline!

 

[No disintegrations]

I bought 3 coils from Advance, to get 1 good one. I had a new OEM module, and took it with me, hooked up my Caspers tester, and showed the clerk what was going on. Did this til I got a good coil pak.
Without testing, it's a crap shoot.
All the ap stores are going to sell you the same stuff. Take your choice. Most have "lifetime" warrantees.
Doing it again, I'd go straight to TR6.
FWIW, the truck coils on my turbo LS, will knock your pacemaker offline!

No YOUR pacemaker! Hahaha

 

[Mike T]

Picked up a Borg Warner from O'Reillys for $56.00 looks decent and made in the USA.

Just installed it and visually the spark is as it should be now. Roads are wet so no test drive yet.

 

[Mike T]

Fixed! Thank you everyone!

Went right to 6k without missing a beat. All PL graphs are in much better alignment.