Finally got my scanmaster. Help with readings

[VadersV6]

Ok. Engine idles like hell, (really rough) but pulls about 18in of vacuum. new IAC, O2, plugs, wires and everything else is working as far as I can tell. At cold startup in the morning, the engine revs up to 2k, then plummets to the point of almost stalling. Then it jumps up and down for a few minutes before it settles. Wish I could figure out whats wrong. The SM shows engine temp fine, so thats not it.
Should my INT/BLM's be showing a number when its not even running? they show 128, which I know to be perfect for both. It also shows those numbers when its running.
Should AF be showing a reading when its not running? Mine does. It shows 03.
I thought there was a way to check TCC lockup with this thing. I guess not. I also found I do have 2 brake switches (old post) I didnt see the other one cause it was too dark.

 

[ES1]

http://www.gnttype.org/maint/quickref.html
Sounds like IAC might be out of line

 

[VadersV6]

Its a new IAC and I did the whole procedure as stated on gnttype, and I still have this issue. i put the old one back in and it still did it. I set the cam sesnor last night. Made no difference.

Ok, Here is all the readings. I can already tell some stuff is wrong. What exactly is wrong, and how do I fix it?

All readings taken at idle.

O2-100-800
AF- 03 with the engine shut off. 05 with it running.
L8 42 while idling in park. Why does it see a load?
INT-124-134
BLM- 146 (dont know why they read fine before)
CLT- 162 Varies from 150-170 degrees (160 thermostat)
ATS- 67 degrees
RPM 675 ( I discovered the dash tach is off by 150rpm)
TPS .44 (right where I set it with a voltmeter)
IAC- 19-24
CC- it starts at zero, then slowly climbs and climbs till it gets to the mid 200's, then starts at zero again and keeps going.
No MAL codes.

 

[Russ Merritt]

BLM @ 146 means it's lean and the computer is throwing fuel at it to richen her up. You have a vaccum leak somewhere and when you fix it you might have to reset the IAC and TPS.

 

[justabuickv6]

What MAF are you running? If stock, make sure the front screen is installed. Mine had fallen out just slightly and my car idled horribly and smoked. My BLM's were pegged.

Pushed the MAF screen back in to place, all is good and everything is back to normal.

 

[VadersV6]

Stock MAF. The front screen is in.

 

[Sader123]

Swap in a known good MAF or duct tape your MAF to the TB and check BLM's @ idle.

I agree with Russ, sounds like you have a vacuum leak.

 

[scottyb]

What chip?

I also don't like that the MAF reads 3 while engine off.

Inspect the MAF-to-turbo hose in detail for leaks as well as other possible locations before the TB.

 

[83ttypecooled]

scanmaster

Hi!
OK, I don't, and never have, used a scanmaster. I am only familiar with tools that use 100% GM acronymese. So, setting that aside, what does the parameter "CC" mean? I was able to wade through all the other stuff, but am puzzled by this. The mere fact that it is changing so rapidly has me nervous.
I await your input to understand the issue more fully!
Dale

 

[ledzeppac]

well you are running a race chip around town aren't you?

Guys could that be the culprit?

 

[BlackBandit]

Is the "CC" the last reading before it cycles back to the o2 and KR? If so I beleive this deals with injector pulse width or duty cycle (could be wrong) and isn't functional unless you have a chip burned to utilize it. If you don't have a chip that uses that function the numbers just scroll and don't mean anything.

 

[XLR8]

I have the old version of SM but the CC should be cross counts and cycle up to 255 and then back to 0. As long as it keeps going up and resetting is showing that your 02 sensor is functioning properly.
Unplug the MAF and see if the engine idles better.

 

[VadersV6]

Ok. Here it goes. I have a chip in there that came from Lou C...a big GN builder down here in socal. It has a little less timing than the stock chip and from what Ive heard, its safer to run on 91 than the stock chip.
I have an aftermarket intake tube I bought from buickGN.com. Its sealed really well and has no leaks that I can find.
I have no other MAfs to swap in, other than the LS1 MAF I have, and Im waiting on shipment of my translator before I can put that on. I did unplug the cam sensor while it was running, and it started stumbling really bad, so thats not it. I unplugged the MAF while it was running, and it immediately smoothed out bigtime.....but then after about 10 seconds, it started idling rough again, which makes me think that the extra rich condition caused by unplugging it, was the only thing that made it smooth out. The rich condition was confirmed by the o2's which started reading in the 800's, and stayed there. All tests were done after the ECM switched into closed loop (blinking decimal shows open loop). I plugged my vac. line going to the pcv valve, and my blm's dropped to 137, from 146 before. I reset the IAC and reset my TPS once again, and it seemed to help a bit. I sprayed carb cleaner around all the possible leak points, and nothing changed....but that trick has never worked for me on any car in the past. At this point, I think the only thing, other than a small vacuum leak somewhere, is bad injectors. Ive run 3 bottles of fuel injector cleaner through it, and it didnt help. The fuel filter is new as well. I did have a big vacuum leak around the base of a fuel injector when I got the car, and I sealed it up with silicone, as a temporary fix until I can throw on my 50 lb injectors (also, waiting on the translator. It helped tremendously when I did that. It took my vacuum from 14 to 18 in. That was back when I first got the car.
its good to know the CC's are working as they should.

 

[VadersV6]

I just noticed there is a forum dedicated to scan tools. Sorry, I should have posted this here.

speedo/scanmaster question-
Isnt there a fiber optic cable coming from, or going to the cluster that tells the ECU what the speed is? VSS related? Given this car has VSS, I figured that the SM would show true speed of the car (my car has gears and the speedo is not corrected, so the analog readout shows MPH too high). But the SM shows the same speed that the needle is showing. Someone in the know, please explain this to me.
Thanks for all the replies guys.....I would be totally lost if it werent for you all.

 

[pacecarta]

vss has anoptical sensor which reads holes on wheel on back of speedo head that spins by the speedo cabe , each revolution the signal sees two windows .
if the tranny gears arefor a 3.42 and you have a different rear or tires the speedo will be off and so will the vss reading as seen by the ecm but they will read the same
Sm shows what the ecm sees
if your gears in the tranny were correct for your rear and tires and the speedo was reading incorrect and there arent any problems with the cable or it connections at the speedo and trans you could have a bad speedo head but the vss would (should) still show the correct speed

youve already established the tach to be innacurate , (as most are ). mine stack dash tach is off at idle and way off at the top

what did you find your cruise rpm to be now that you have an accurate tach ?

your Sm readings all look ok
you should show a L8 (load ) around 40 at idle , it goes to 255
but your BLMs are high and as mentioned as you find the leaks and fix them your idle iac will change.

 

[VadersV6]

Thanks for the detailed response. Whereas before i thought I was at 3200rpm at a true 70mph, I'm actually at 2925-2950 at that speed. The search for the vacuum leak continues......when the damn rain clears up

 

[83ttypecooled]

Hi!
How about an intake leak? I'm thinking it could be in the lifter valley. Try pulling the pcv valve and breather cap, holding your hand over the tube,while plugging the pcv fitting. Do you feel a strong pull? An idea, anyway.
Dale

 

[VadersV6]

I tightened my intake...some of the bolts were a little loose, and the rough idling issue I had fixed for the most part (bad plug wire), came back. I dont get it