Started all of a sudden without warning. Runs rough - and no power. Almost feels like it's would stop if I had to go uphill.
My wife told me it got hot a few days ago going about 65. She turned off the A/C and it cooled back down.
I drove it since then - and no problems until today. I let it cool off, checked all fluids, etc.
(From what older, non-computerized cars felt like...) It does not feel like when one spark plug wire would come off, it feels more like when a vacuum hose would come loose.
Could it be a vacuum leak somewhere? Exhaust sounds fine.
Don't hear any 'hissing' under the hood.
Any opinions would be helpful... check engine light came on at the same moment it started doing this.
There are a few service bulletins on a problem similar to yours but first I need to know what trouble code is putting the Check Engine Light on.
You would need to have the truck checked out by a mechanic with a scanner to see if any trouble codes are set. If you don't want to bring the truck to a mechanic you can go to your local Auto Zone auto parts store and they should tell you the trouble codes for free. Check to see if they are still doing this. Depending on the code(s) is which service bulletin I will recommend.
For instance I listed one service bulletin below on one possible cause. It all depends on the trouble code stored in the PCM's memory, we can go on from there.
If the data trouble codes (DTC) are P1516, P2135 and/or P2138 it is possible you have a internal problem with the PCM and it would need to be replaced depending on the serial numbers on the PCM label.
The serial number is read left to right. The last digit of the year is the 9th character and the Julian date is comprised of the 10th, 11th and 12th characters and is used to determine the PCM build date. Refer to the example below to read a build date from the PCM serial number:
* 8 6 Y N AU K 1 5 3 2 5 0 R P N *
If the PCM year and Julian dates are between 5182 and 5304, replace the PCM. Refer to the Part Catalog at the dealership to order the correct PCM for your vehicle application, if necessary.
Vehicles with PCM built outside the dates should refer to the diagnostics procedure for DTCs P1516, P2135 and/or P2138.
If you can get back to us with your results, we can continue with the diagnostics from there.
Parts of this article are from the Alldata automotive information website.