89 Chevy Silverado issues.

the only time my truck was running rich was when the bad t stat was in it, after that it was throwing lean, until I replaced the map and the tps. now no codes, no smoke .
Just for the Halibut, im going to order a fuel line tee and see what my pressure is running, and I may take the injectors back out and do a bench flush on them. really clean them good and see what happens. like I said sometimes it idles for several minutes, then if I rev it a bit, or drive it, it goes into like a little diagnostic slow ramping surge a few times, then levels back out and idles ok.. it seems to be either relearning something, or throwing a test out,. with everything out of whack the way it was, I think it may be trying to fine tune itself, either that or its not getting results it wants from something and its checking again.. thats what it seems like . If that little "hunting cycle "every so often would go away, it would be perfect.

I may have asked a confusing question, what im asking is if it has a block heater, will it have a 110 volt plug somewhere on the vehicle to plug into house current, or can it be heated by the vehicles 12 volt battery? there is no plug anywhere to plug it into a house extention cord

The 110 cord plugs in that goofy shape connector on the block heater and you just route it out to where you can get an extension cord on it. Yeah, looks just like any 110v cord. No switch anywhere just plug it in and it’s on

It shouldn’t be fine tuning itself,it’s not a learning type of computer. It’s definitely trying to do something based on inputs

I just went look again, I think your right I think it is a block heater which is larger on the pass side, and a knock sensor on the driver side. the block heater looks like it had something going too it but got pulled off, there is just a prong of solder sticking out of it.
I ran the truck a while an it seems like once its warmed up good, it idles really well and steady. with the cold nature of these trucks and large radiators, It may also be switching back and forth in open loop a bit, and causing the little "episodes"< when it is warmed up good its quite steady and smooth. its like flipping a switch when it does it, then flipping it again when it comes out of it. and the engine is not in danger of stalling, it doesnt drop down that far, just enough to feel the stumble. I watch the floor shifter when its idling and it is fairly still, just a slight vibration coming thru it, and moving just a slight amount. If I had a scanner that I could see and verify this it would be cool. in hot weather I may not even see it do this. when its 105 F out it doesnt take the engine long to get to 180F. if its hopping back and forth out of closed loop, then the IAC and tps would be controlling it, and the TPS does control timing and fuel. the IAC just air. this would make more sense than the knock sensor theory.
looks like the 02 sensor comes online at around 600F. Uncle Haynes isnt too clear in the manuel on what function the 02 sensor has, though it does say it helps control fuel. Haynes makes better drawers than repair manuel s by far.!!

The reason I thought the Engine ecm may be a learning or (adaptive), computer is that the 4l60E transmission is an adaptive transmission system. I think the module inside the transmission may handle this. The transmission monitors the shift conditions, and parameters and tries to duplicate your driving habits. I drive like slow poke gonzales, (speedys cousin), and I can hardly feel it when my transmission shifts. If I drove aggressive and had the rpms up every time it shifted, the transmission would tend to want to shift in that manner.

Your 94’ will learn, the 89’ will not. The 94’ has a few more things in the puter not just the prom. I don’t think the trans went electronic control till about 92’ish. It uses the engine calibrations in combination to know when to shift. Using tps,map, vehicle speed etc. it’s all housed in the ecm,but called pcm as now it controls the powertrain and not just the engine. I through a cb in my 93’ to take a road trip. I just quickly tapped into a 10 amp fuse I believe said cig lighter,well I popped it. The trans was stuck in second, thought I blew the trans. Everything else was fine,I didn’t realize at the time my cb wasn’t working either. It wasn’t till after several hours of dicking around I wanted to at least fix something and changed the fuse and whala,back on the road.

good to know, good way to determine what is controlled by what its called, ECM or PCM.,
got a drip coming from rear main seal, have u ever tried a product called AT-205 RESEAL BY ATP.. It has a 4.5 star rating and scotty kilmer said he used it with good results for 20 years. I was told that the clutch was replaced before I got the truck, from the guy I got the truck from but people lie so much Its hard to believe anything anymore, . I couldnt imagine not replacing the rear main when they had the manual tranny off, but hey , its 2019 . im hoping it got a little shrunk from sitting likely a year 0r more. anyone who doesnt change a 10.00 seal that takes 2 minutes or less when they have the transmission out would be amazing to me, I will try the stuff and report how it works. had neck surgery in jan and surely cant be pulling the transmission on it for a while.
also anyone who does a rear brake job, DO NOT use brake best hardware kit, the e clips that hold the E BRAKE lever onto the shoe is defective., Im fixing it permanently, I drilled a small hole thru the pin, pushed it brake pad and lever, put washer on other side, and small cotter pin in. a roll pin could be used as well. what happens is that E CLIP comes off, or breaks, then pin pops out, falls into brake hub, and the E brakes dont work anymore.

I’ve never used at205. I’ve seen plenty of people that “know what there doing” destroy new parts including lots of seals. Even after 6yrs of vocational high school and college specific automotive and heavy equipment knowledge and even a year at mmi for motorsports stuff,I can still get in a rush or be absent minded or sidetracked and ruin a good part, talk about something that really Pisses me off.
I believe those e-clips aren’t like real e-clips, there meant to be bent manually together at the open end to secure it.

the E clips that came with the kit both snapped, like they were made out of the wrong type of metal, I had to go buy a generic e clip Kit, and those failed too, the E clip should have spring to it, and it didnt at all it just broke while trying to push it onto the pin groove. Alot of force pulls down on that Ebrake arm, im amazed the eclips are even used at all, as there is some side to side force being applied as well as up and down. with the hole and the cotter pin in it now, its not going to come off again until I take it off. with the truck being standard, the e brake gets used alot, so it should stay fixed now.

They are C clips,, Cheap Chinese junk!!!! ha you cannot even take for granted that small hardware items are of any quality anymore.. , I also doubt the chinese care even less abt what they send here, with the trade war going on,., they dont give a rats SS if it works or not or abt safety.