2F with Sniper running rough all the sudden (1 Viewer)

[JDNs78FJ40]

Sniper has been awesome, especially since I dialed in the timing a few months back. However, when I fired it up yesterday after it sat for a week it is running rough. Seems to hesitate and just sounds off like it is stumbling on itself. No back firing and it turns right over. All the numbers on the Sniper handheld look great. Anything I should specifically be looking for? I checked timing and it was perfect.

 

[Steamer]

All the numbers on the Sniper handheld look great

I was thinking O2 sensor, but if the AFR looks good, probably not.

 

[zerotreedelta]

If you can (with the SD card installed), flip on logging right after start and go for a drive...then share the log file here. Might lend some insights.

(It's something like Home > Logging > Start Logging, but can't recall exact flow)

 

[JDNs78FJ40]

If you can (with the SD card installed), flip on logging right after start and go for a drive...then share the log file here. Might lend some insights.

(It's something like Home > Logging > Start Logging, but can't recall exact flow)

I will do this! Thank you for the input. It wouldn't be something like my valves need adjusting, correct? Just so strange it just started running like crap yesterday after it sat for a week.

 

[peesalot]

Plugs.

 

[zerotreedelta]

Doubtful it would be something like valves... next suspicion would be more like ignition as mentioned (plugs, coil, etc).

The Sniper logs would at least help rule out the fueling aspect at least, or things like problems with the RPM signal feeding the Holley. Every bit helps.

 

[85roktoy]

What ignition are you running?

 

[JDNs78FJ40]

What ignition are you running?

Stock ignition with a DUI distributor. I think that is what you are looking for

 

[JDNs78FJ40]

@peesalot was spot on! Pulled all the plugs and #4 was dirty with oil.... An engine rebuild is in my future since the old 2f is tired and burning oil. Cleaned all the plugs and she's back to purring like a kitten! Thanks all!

 

[Oregon LC]

Same exact symptoms as @JDNs78FJ40 was having. Truck's been sitting in storage all winter. Fired up today but did not want to idle and lots of stumbling.

I ended up not giving up and taking it for a drive after about 5 minutes of trying to keep RPMs up it started running just great. Drove it for 10 mi before I parked it. Everything is running great except I am noticing a slight stumble in the idle about 2 or 3 times per minute. AFR numbers are what they are at a healthy idle.

I think the engines got a pretty good amount of miles on it, haven't checked the plugs yet, but as always ran good since I owned it.

 

[derail]

I'd start by making sure that the injector wiring clip is still secured where it's supposed to be. While you're there, I'd zip tie them or replace them.