OK, first off, sorry to mods, and everyone but I wanted to make a new post regaurding my issue so I don't miss anyones useful knowledge.
First, any newcomers can read my original post, if you already haven't. https://www.thirdgen.org/forums/tpi/...uling-out.html

I just got done putting in new ac delco R43ts plugs, rotor, and a new set of Jegs Pow'r wires. Car started up quickly, unlike before, and now will stay running. At first, it was misfiring, and popped a couple times under throttle, but after about 3 minutes of running, this subsided, and the car actually had good quick throttle response. Scan tool readings are another issue. I believe some are not correct at all. The following readings were taken after the car had been running for about 10 minutes.

Coolant temp-215F
Loop status - OPEN??????
O2 constantly read LEAN but exhaust smelled RICH AS HECK. (open loop=more fuel, as most of us know, so I wasn't surprised.)
Fuel pressure never dropped below 35psi when running, and would increse several psi under acceleration.
IAC- 56
Injector pulsewidth-151 (would fluctuate to as low as 108)
MAT 87F (seemed about right, ambiant air temp is about 60 degrees and after 10 min of running i would think the air coming in the intake coule be that warm)
Integrator-128
BLM enabled-NO??
O2 snesor MV 129-142 NO HIGHER and NO RAPID SWITCHING My knowledge tells me this needs to be switching voltage high to low at a good quick pace.
O2 crosscounts-58
ESC counts-3
Side note-Fan request was on since coolant temp was 151 F, but the fan did not come on until 223 F. Not sure if thats important on this old of a car. Might be normal?

So, the car is NOT entering closed loop it seems. O2 sensor has some control over this correct? It must reach a certain temp before it begins sending signal to the ecm to pay attention to it right? I have a new o2 sensor but did not yet put it in. I wanted to see what would happen after plugs, wires, and rotor change. Turns out it helped DRAMATICALLY, but now I need your help to get to the bottom of these readings. ALL thoughts, ideas, and suggestions welcome. As of now, I am going to change the o2 sensor tomorrow after work. Could the o2 sensor be the final piece to this crazy pulzzle that is my old delapidated Iroc? Or could the ECM be going nuts? Thank you all.

 

I would just replace it and see if it improves.

Is that injector pulsewidth 1.51 to 1.08 ms (milliseconds?) If so, what injectors?

 

my fan request is always on yet mine doesnt get turned on by the ECM till 238. thus why i wired in a fan to kick on at 200. also you are getting cros counts, meaning the O2 is crossing the threshold for a crosscount, is your exhaust stock?

 

well from doing lots of reading, if you are running headers,then you will need a heated 02 sensor... apparently exhaust doesn't get hot enough to the point of triggering a closed loop signal...

 

BTW, what are you using to data log? a laptop or a scanner?

 

thats what i was getting at, cuz as soon as i upgraded to headers i had zero cross counts and stayed constant lean

 

I now think this issue was my main problem when it came to emissions... it was a PITA to get it within specs... WOT never had a problem, fun car to drive...

 

3 wire heated o2 from 93 chevy pickup solved that problem

 

Not running headers, factory exhaust and all pipes, and hoses appear in place. Smog pump belt is not on though, as it appears the pully siezed up. Injectors are new bosch 3's just installed. Please see my other post for additional details.

I am using a scantool by actron to view my data. It's old school. lol. It's got like a gameboy screen. Wish i could use my genisys but i dont have the TPI cable required for our engines.

I have a 86 z28 that is my daily driver with the same engine, trans, but has hooker 2055 headers, and i use a factory single wire o2 on it with no problems. If need be, i can swap out ecm's real quick if my o2 sensor doesnt solve the problem. I also plan on looking at my data on it later on for a o2 sensor comparison. My z28 runs great, so I should be able to believe whatever it tells me.

 

Your fans are working correctly. These cars run HOT for emissions reasons. The first one comes on around 224* and the second one comes on around 240* (can't remeber exact temps but that's pretty close). There are a ton of threads about rigging fans to come on sooner but that is normal.

I'd be interested to know if a new O2 sensor solves your problem.

 

Thank you 88gta_hiflyer. I figured it was normal cause like you said, these are smog engines lol. I will update with the o2 outcome tonight.

 

Ok, new o2 sensor is in. Guess what? It fixed SOME problems....Now, my o2 millivolts fluctuate quickly like i would expect, and the car actually went into closed loop. It runs BETTER, but still, something is not right. When cold, i still had tip in hesitation, and somewhat rough idle. It got better as it warmed up however. Idle was not always consistant, sometimes it idled around 600 rpm which was good, but others it would stay up around 1100. According to my scantool, the iac was quickly responding, but averaged about a 70 count (or percentage, whatever this ancient scanner is measuring in). I actually felt good enough about the car to run it up and down the street, and it did seem lower on power than it should, and did bog initially when accelerating from a slow speed, or a stop. However, it went away as the car got rolling and as engine rpm increased. At one point, when in park, the idle raised itself up and down. I did look for vacuum leaks, and think i have a couple small ones. The pcv valve grommet in the valve cover is hardened up and the valve will slide in and out easily with very little resistance. Also, the rubber molded hose on the opposite valve cover, that attaches to the aluminum pipe and the throttle body is not fitting very well. I need to come up with a replacement for that. BUT, I still dont feel these are my only issues. Something tells me something else is going on. Code 44 also set......Lean exhaust. Go figure. lol. Well, I am gonna dig into more vacuum leak testing with some propane, or brake clean and I'll let you all know. Thanks for your help so far.

 

google EGR symptoms... might be your EGR...

 

swap maf sensor w/one in your other car.your symptoms remind me of mine when my maf got flakey and never set a code and even output in gm/sec was good.worth a shot.