This is my 1981 240 wagon GLT 4 speed + OD. My question is: What causes the engine to miss? (more info below)



So It's got a miss that I noticed, but didn't seem like a big deal. It's been more of a problem lately. It's like the engine shuts off for a moment, then springs to life briefly, then it repeats. Not consistently though, more or less randomly.
Accelerating from a stop is fine, until I'm cruising in cold weather for a minute or so. on warm days it's happy as can be at any speed for any amount of time.

Any ideas?

 

I'm going to attempt to capture it on video. Anyone interested in a Video of this thing missing?

 

possibly a clogged fuel filter, or weak fuel pump(s). If its temp specific, i'd hazard to suspect the fuel pump, maybe the in tank pump is sketchy.

thats a CIS (K-Jet) car, right ? so no air mass meter to mess things up.

 

Thanks for the reply! Yes, it's k-jet B21f I believe. After a good nights sleep, I've decided I'm gonna run through the usual weak spark culprits before I go chasing fuel issues. Hopefully it's plugs, wires, coil, cap or rotor.

I've read that overly rich fuel/air mixture can cool down spark plugs, causing a mis-fire. Is there any truth to this? And can I check my fuel to air ratio? I do have an lambda o2 sensor, if that helps any.

 

If it is the fuel pump, whats the best way to verify that?

 

fuel pressure tester, hooked up via a T inline where hte line fromt he pump goes into the fuel distributor.

 

Thanks a bunch Pierce! You've been very helpful. I found the problem this morning. After checking the cap, rotor, plugs, wires, I decided to make sure it wasn't low compression. Before starting the compression test I went to disconnect the coil, and found the red/white wire was barely connected, and the spade terminal was covered in black stuff. I could see where it had been sparking across the bad connection. So I cleaned and crimped the connector and now it runs like a dream! Who's idea was it to leave that connector open to the elements? haha, anyways thanks again!

 

they usually last 25+ years the way they are, at least here on the left coast.