I did a test on my IAC this afternoon on my 87 Ranger, on cold start up the idle is erratic, somewhat goes away once it warms up a little, but getting it going above idle takes some coaxing hitting the accelerator only causes it to bog down. So I checked the IAC, according to the book it should be between 10-14ohms, I was getting 10.2ohms when first connected to the multimeter, then it was dropping to around 9.1-9.5 and falling...I took the IAC off the intake, realized there's 2 screws in the end of it on the side where the electrical connector is and took that apart, as I did something popped back into place. I assume the plunger is sticking, and I put it back together and back on the truck, now it idles just fine and with throttle application it'll accelerate normally now...so I ordered a new IAC.
I also could not for the life of me figure out where the EGR valve is...finally thought hey follow the dang EGR tube from the exhaust back up...ahh under the throttle cable plate LOL...wow, I must need new glasses. I unplugged the vacuum line to the EGR valve and plugged it, started the truck no change in idle....so I assume that wasn't the issue as from what I was reading if the EGR valve was the problem it would have started idling weird or would have died at idle if it were leaking. (Haven't ruled it out yet, but seems to have been the IAC rather than the EGR). Previously I was having issues where it would cut out and almost die, turned out that issue was the TFI module, and a diode or something inside the distributor...that issue has been solved with a replacement distributor, and now its down to the last little minor idle issue with that IAC it seems like and it should be good to go here in about a week when I get the IAC from Rock Auto. I should get frequent shopper points I've ordered enough from them lately LOL.
One thing is for sure, these RBV's will make you learn how to use a multi-meter, read service/repair manuals, and troubleshoot LOL. I don't mind that part, I just hate turning wrenches on them, seems everything that breaks is always in a ridiculously stupid location to get to HAHA!!!!