Rough, hunting idle and down a cylinder '88 3.2

[PopsRacer]

Everything was running nicely, but I started to hear a little tick noise that sounded like perhaps I didn’t tighten a spark plug enough so I decided to check the torque on all 6.

They were all a bit loose (didn't use a torque wrench when I put them in, my bad.)
Now they are all 22ft/lbs.
Had a tough time getting the leads back on, not sure why.

When I started it back up it sounded like it was missing at least 1 cylinder and the cold idle was hunting pretty badly, nearly stalling at random times.
* i re-checked all of the leads to make sure they’re connected solidly
* engine is running pretty badly, but IR thermometer seemed to show cyl 4 & 5 were on the cool side relative to the others. I checked their connections twice but found nothing.

It feels like I must have bumped something, but I’m not sure what. All the electrical connectors are in place (injectors, crank sensor & HT sensor, etc) maybe a pcv hose or something behind the airbox? It was super smooth after I installed the plugs and rotor/cap.

Relatively new stuff just as background.. I’ll assume anything can be bad though.
cap & rotor
plugs
fuel pump
DME Relay
Coil
HT sensor
cleaned up engine ground on intake manifold.

I have not checked the leads from end to end to ensure continuity yet. Possible I broke a lead I guess.

What would you look at first?

[ant7]

Coil, which one have you fitted in place of the original ?
Also, if you have some spare leads, try swapping them on 4 and 5 cylinder to eliminate a bad lead, try the simple things first.
Ant.

Originally Posted by PopsRacer

Everything was running nicely, but I started to hear a little tick noise that sounded like perhaps I didn’t tighten a spark plug enough so I decided to check the torque on all 6.

They were all a bit loose (didn't use a torque wrench when I put them in, my bad.)
Now they are all 22ft/lbs.
Had a tough time getting the leads back on, not sure why.

When I started it back up it sounded like it was missing at least 1 cylinder and the cold idle was hunting pretty badly, nearly stalling at random times.
* i re-checked all of the leads to make sure they’re connected solidly
* engine is running pretty badly, but IR thermometer seemed to show cyl 4 & 5 were on the cool side relative to the others. I checked their connections twice but found nothing.

It feels like I must have bumped something, but I’m not sure what. All the electrical connectors are in place (injectors, crank sensor & HT sensor, etc) maybe a pcv hose or something behind the airbox? It was super smooth after I installed the plugs and rotor/cap.

Relatively new stuff just as background.. I’ll assume anything can be bad though.
cap & rotor
plugs
fuel pump
DME Relay
Coil
HT sensor
cleaned up engine ground on intake manifold.

I have not checked the leads from end to end to ensure continuity yet. Possible I broke a lead I guess.

What would you look at first?

[ErrorMargin]

Originally Posted by PopsRacer

What would you look at first?

Very first thing: start the car and get it warmed up. With the car running, disconnect each fuel injector harness connection, one at a time. If you hear a change in how the engine runs (slower, rougher, etc.), then you know that cylinder is working. If no change, then something is wrong (could be spark, fuel, timing, etc.).

The whole process should take less than 10 minutes and is relatively easy to do.

Franny shows how to do it in this video, I've cued it to the correct point for you: https://youtu.be/tRn_nstudAQ?t=336

If you get through that process and all the cylinders seem to be working then you can start looking for systemic issues.

[PopsRacer]

I dug in, expecting something to be busted. I measured all of the spark plug leads for continuity and DCR, and then I started pulling out all of the plugs to take a look at them… aaaand the very first one fell into the engine. Which shouldn’t happen bc there is that rubber collar inside the Klein factory tool. Except it had come out at some point (it had stayed with plug #2 which was why getting the lead to feel like it was seated was such a pain…) I used an alternate spark plug tool to get the other plug out, and then removed and checked them all (to make sure I got the rubber part out!) and then put it all back and now it purrs again.

I feel dumb, but I’m glad I didn’t break anything. . Thanks for the replies!

[Johnr352]

Originally Posted by PopsRacer

I feel dumb, but I’m glad I didn’t break anything. . Thanks for the replies!

I spend so much time in this state - it's my go-to first check...

[ant7]

Good to know you sorted it!
Ant.

Originally Posted by PopsRacer

I dug in, expecting something to be busted. I measured all of the spark plug leads for continuity and DCR, and then I started pulling out all of the plugs to take a look at them… aaaand the very first one fell into the engine. Which shouldn’t happen bc there is that rubber collar inside the Klein factory tool. Except it had come out at some point (it had stayed with plug #2 which was why getting the lead to feel like it was seated was such a pain…) I used an alternate spark plug tool to get the other plug out, and then removed and checked them all (to make sure I got the rubber part out!) and then put it all back and now it purrs again.

I feel dumb, but I’m glad I didn’t break anything. . Thanks for the replies!