I'll try not to bore everyone. Recent history I've had a bad oil leak. Was told it is from the rear seal. That has been going on for a while. Also for more than a year I have had fluctuating idle. It is worse in gear, but also in park. The volt gauge would take a huge fluctuating dip. The more load the worse it was (is). Had new alternator put in no change.
During all of this, within the last month would get intermittent check engine light. I replaced the battery about a week and half ago. I still had a voltage issue.
Then I decided to fix leak. I dropped transmission and replaced the rear seal. I also replaced the negative cable. (It still leaks)
So I suck at being a shade tree mechanic. I know my pan gasket needs replaced, but that's a job for another day and hopefully someone else.
But let's forget the leak. I am an electrician. I am using a Haynes/ Chilton's manual. I have not obtained codes.
I checked TPS. KOEO voltage good and resistance good.
I checked BPA-ISC w/KOEO I was getting milli-volts, not the actual voltage that the manual says.
Does this mean that I have a bad ECM?
The first thing that should be done is to find out what trouble codes are stored in the computer memory.
You need to start at the basics, if you don't have a scanner or code reader then you can go to your local AutoZone auto parts store and they can scan the computer system for free and be able to tell you what the trouble codes are. Then you can repair what is wrong and then go on from there.
Engine surging can be cause by a few things like a sticking TPS, vacuum leak at a hose, intake manifold gasket, throttle body base gasket, clogged fuel injectors, EGR valve and the list can go on.
The voltage issues can also be investigated through the scanner and can be a big help in diagnosing the problem and coming up with a repair.
See if you can get the system scanned and get back to with the results and we can go on from there.
If you really can't do these types of repairs you would be better off bringing the truck to your local automotive professional. In the long run it could be cheaper for the repair then swapping parts on your own, spending that extra money and still having the same problem.
Took vehicle in to have codes read at local parts store. The code reader code not read the codes and could not clear the check engine light.
Another issue (may or may not have anything to do with anything else), is while in drive during acceleration there is some sort of whistling noise.
The whistling noise could possibly be a vacuum leak coming from a cracked vacuum hose or gasket like an intake manifold gasket, throttle body base gasket, or other related areas that have manifold vacuum in it.
You can gently spray carburetor cleaner around these areas (be careful not to soak the areas because this stuff is flammable). Always work safely to avoid a fire.
A mechanics stethoscope can also help by listening for a hissing or whistling noise at these gasket areas.
Keep me informed on your progress.