Slight shake after extensive tune up

[Cb87]

Did the fuel filter, double platinum plugs, new AC Delco professional wires, sea foam top end treatment and an oil change today. Plugs are all gapped properly, noticed when in park the truck has a slight shake which it didn’t have before. RPMS are just a touch over 500 at idle. Any thoughts on what might be causing it? No CEL, and truck runs great down the road under normal driving only seems to do it in park. 98k miles, 4.0L

 

[Gmctyphoon]

Check your plug wires. It’s super easy to mix up the driver side on the coil. The cylinder numbers are on the coil, but they’re not in order on the driver side.

 

[Gmctyphoon]

 

[JAWIT]

Just a thought. If you disconnected the battery for any length of time when you did the tune up, the PCM probably reset itself to factory specs and your vehicle may just need to relearn them over time.

 

[Cb87]

View attachment 320283

I did them one at a time specifically so I wouldn’t mix them up but I’ll double check. If it were wrong for some reason I would think it would have thrown a CEL fairly quickly no?

 

[Cb87]

Just a thought. If you disconnected the battery for any length of time when you did the tune up, the PCM probably reset itself to factory specs and your vehicle may just need to relearn them over time.

Battery was never disconnected

 

[Beachcomber86]

Check your evap hose. Replace if it turns your fingers black.

Then look at this thread.

Found my ghosts in the machine

Hey guys, If you've got unexplained, and intermittent, problems, here's a possible cause. My Ex has developed what is best described as the "hiccups" at idle. It doesn't happen all the time, and feels like a misfire. No codes, though. So I thought I'd just inspect the engine for (esp the...

www.explorerforum.com

 

[Tommylee1282]

Check your evap hose. Replace if it turns your fingers black.

Then look at this thread.

Found my ghosts in the machine

Hey guys, If you've got unexplained, and intermittent, problems, here's a possible cause. My Ex has developed what is best described as the "hiccups" at idle. It doesn't happen all the time, and feels like a misfire. No codes, though. So I thought I'd just inspect the engine for (esp the...

www.explorerforum.com

I just had this happen after a tune up the line from the purge valve to the intake, to replace get 36” of 3/8 fuel hose it’s 7 bucks at advance auto, another lesson I learned from gremlins after the tune up was the throttle position connector wires losing their insulation just like the link above