2003 3.0 Ranger Tremor (edge) edition, 135k miles.

Ok so I went outside after remote starting my truck tonight.

Got in, accidentally hit the brake and killed the remote start, then started it really quick afterwards. I've done this a few times with no problem, but this time I noticed it ran rough. It seemed to smooth out at 2000 RPM or so. I decided to try driving it, to which 2nd and 3rd gear shifted rough as heck. I noticed immediately after shifting, the truck sat at 400-450 RPM's (while moving) which is way abnormal, I believe i typically see 1000-1200.

So then I tried stomping the gas. The symptom all 3 times, was when it would be at about 2500-3000 RPMS, the truck damn near stalled. The RPMS dropped substantially when it should have gone up. Strange.

Parked it. Re-started it after taking a look to see if fuel line was OK (just replaced fuel filter), didn't touch anything. Started it up, worked fine. Purrs like a kitten, shifts like a dream, acts as if nothing happened at all.

Drove it for about 5 minutes. Turned it off. Let it sit 2 mins, then re-started it again. Again, idled just fine, no more bogging, rough shifting, or low idling.

What the heck???

Did I confuse the truck when I canceled the remote start and then turned the car back on too quickly?

Is something going bad in the truck?

I do have a vaccum leak check engine light on, and we were unable to find the leak. My mechanic said it's really common and not likely a big deal. And it hasn't been a big deal the 12,000 miles I have driven this way.

Been a great little truck, I hope it's OK.

Any input?

 

Update: Just drove it to and from the pet store (about 8 miles round trip) today, no issues.

 

I had a similar issue on my '03 but it is a 4.0. it's a vacuum leak. I found mine on the main vacuum line at the front of the engine passenger side buried under a couple of hoses. it hooks to the manifold and then does an immediate 90 to the back of the engine. I madw a hard plastic angle with a part from the store and rubber hose. the old one collapsed and cracked.

 

If this happens to be your problem here is a how to thread to fix it.
https://www.ranger-forums.com/4-0l-o...mon-cel-93776/

 

I'm having the exact same problems in the exact same truck, except under load in high RPM it will misfire (3rd gear, 4000ish RPM). The code reads misfire on start and a 4th cylinder misfire. I replaces o2 sensors, coil pack, spark plugs, and plug coils. Don't really know what else to check at this point... help...