So I have a 2000 mazda that's really just a Ford ranger wearing a dress. 4.0L v6 4x4 with about 100k miles on it. It was idling a little sporadically which I read cleaning the TPS and IAC with electrical contact cleaner and dielectric grease could be a potential fix for this.

So I went and got some and began taking apart and cleaning my electrical connections. I ended up doing the TPS, IAC, 2 sensors on the air intake (MAF, and not sure the other), as well as the temperature sender and sensor as my temp gauge doesn't currently work either.

as per the instructions I sprayed the connectors, cleaned them up let the cleaner evaporate, lathered up with dielectric grease and reconnected.

took it for a short test drive and all seemed fine, the pulsing idle problem it had before had gotten a little bit better. Fast forward a few hours, I loaded up the dirtbikes (approx. 600lbs) and got on the highway.

Now the truck feels like it's surging under load, going uphill at lower RPM was the worst sometimes forcing me to slow and gear way down. The exhaust is backfiring and it's running really rough. Limped her home and took the weight out of the bed and have time to tinker with things today.

From what I read sounds like the fuel pump may be going, and that increase in weight and load is what put it over the edge to where I can noticeably feel it? Or is it more likely I damaged one of those connections while cleaning?

TLDR;
2000 4.0L V6 4x4, cleaned IAC, TPS, MAF, temp sensors to resolve a loud exhaust/slightly rough idle. Test drove up to 50mph no issues. Took on highway with 600lb weight in bed, experienced surging, backfiring and running very rough particularly under heavier engine load. Fuel pump? Or did I wreck a sensor?

 

Welcome to the forum

Dielectric grease is used because it DOES NOT conduct electricity like regular grease can, which can cause a short
So you do not want dielectric grease INSIDE on the contacts of the connectors, you apply a little around the edge of connectors so when pushed together it displaces any air and seals connector from air and moisture getting in in the future
You want metal on metal connections for the wires/pins inside the connector or they can't work

Check MAF sensor connector first

 

Ran it with MAF unplugged didn't make any difference, did I fudged these connections? Or can I take more electrical contact cleaner and clean them up. Literally the thread I read told me to put it right on the pins and lots..

Here's what I did quoted from the original article:

"Disconnect both connectors for the IAC and the TPS and spray the contact cleaner on both ends and reconnect and disconnect both several times to clean the contacts. Spray liberally again and again connect and disconnect several times to clean contact pins. Let the connectors hang disconnected for 10 mins so the contact cleaner fluid evaporates.

Fill the pin holes in both connectors with dielectric grease. Don't be scared. Use a lot of the dielectric grease. "

 

Yes, "if its on the internet it must be true", lol

But that would be an incorrect use of dielectric grease
Just use some common logic on the point of using "dielectric" grease over any other grease inside an electrical connector
Dielectric grease is used because it does not conduct electricity, so can't short out connections
If it blocks/prevents electrical connections then............................well you get why it shouldn't be used on the metal parts, lol, logic and common sense

Google: dielectric grease

Most sellers will stress that you do not get it on the actual connectors, the metal parts, just use it to seal the outside plastic part of connector
"The grease does not conduct electricity, so it shouldn't be applied directly to the mating surfaces (pins and sockets) of an electrical connection."

Yes, unhook connectors and clean out the grease then reapply just on the edges

And you should post a comment on whatever site/forum/post that has that bad info just to warn others