So yesterday it ran just fine. Did some routine things...cleaned battery cables, cleaned air filter, adjusted tire pressure and added a bottle of STP gas additive to half tank of gas. The check engine light had been on for sometime but since cleaning the cables it has remained off.

This morning while waiting in a drive thru it suddenly dies but starts right back up. This evening while driving down the highway something just felt wrong. Maybe not quite as much power as normal and the RPM seems to be lower than normal. Idling at around 400 and about 1600-1800 at 70mph. If I remember correctly it normally ran between 2200-2500.

Could this be something I caused?

 

I would make sure your cables are on both ends are on tight. You said, cleaned your air filter? I'm assuming you have a K&N filter or something similar? I have never used the STP additives so I don't know if this could be a cause. What was the code that was on before you disconnected the battery. Depending on the code, it could take a while for that sensor to be checked again.

 

1800rpms at 70 sounds about right for a 4.7 w/ the 545 rfe transmission behind it (i turn 2k rpms at like 78)

400 is just a bit low at idle, how does the TB look? if its dirty i would start there with cleaning it.

 

I run about 2200 RPM @ 70 with 3.92 gears (4.7 on a 2001 with 545rfe tranny and AWD/4Hi/4Lo NV244 transfer case). Idle is 700-ish. I wonder if the 1800 @ 70 and 2200 @ 70 difference may depend on which gears you have or if the 2WD/AWD transfer case may impact the RPM as well.

Both of those RPMs seem "normal" for the speed depending on the gearing. However, 400 at idle does not - at least to me. I would think under 600-ish would start to stall.

I did find this interesting thread: https://dodgeforum.com/forum/1st-gen...nd-stalls.html

And this Google search turned up almost too much info... now there is no telling!

Let us know when you find the answer....

 

the 2001 4.7 came with a 45rfe transmission not a 545 (unless you upgraded it at some point)

the transfer case does not affect speed output, they are all geared the same (low range is another story but we are talking normal ranges here)

the rear end gears could be the difference, my father has 3.92 rear gears in his truck and he does do about 70 at 2k rpm.

normal idle for these engines is right around 500 rpm (mine idles there and idles so smoothly some people think i shut the truck off at stop lights) 600 -700 is also in the acceptable range for idle speed.

 

Well.....after getting rid of the tank of gas containing the additive and filling with the higher octane she seems to be running better. Has not died since the last post and is idling around 600 rpm and 1900 @ 70mph. I'm chalking it up to the fuel injector cleaner settling and keeping my fingers crossed that I don't find a bigger problem in the future. Thank you all for trying to help

 

3 words.... NEVER USE ADDITIVES!

 

Lesson Learned!!! Thank You

 

my 2001 4.7 does 65 at @1900 rpms. does this sound normal?

 

sounds a little bit high to me, but then you only have 4 speeds in the 01, and with a 3.92 rear end im not sure where it should be.

basically it depends on some of the options installed on your truck