therealalkybird

I have just started with the WinALDL diag program and I have been trying to figure out some issues about my bucket that have been stumping me. I have o2 readings that will fluctuate from .0004 to .991 all within the space of one update frame. Along with that you would expect to see a BLM or INT change but there is none. Also when there is a BLM/INT change there is no change in the o2 reading. I have replaced the o2 sensor to no avail. Also this vehicle permanently idles rough. I have adjusted the timing, fuel pressure, different chips, once again all to no avail. Is my ride just a hunk of trash or am I doing something wrong? My fuel pump is brand new, there is no fluctuation of pressure, it sets right at 12psi steady, I am using the holley 670 TBI unit. I have a 350 with a 1228746 comp in an 89 firebird with a 700r4 trans, 2400 stall, 3.70 9bolt rear, approx 9.5:1 compression, cam: .445 intake lift .465 exhaust, 224/228 duration, 110 centerline, 114 LSA. Also one problem I have is that the timing will jump slightly (approx 4-6 deg) when it is idling. I realize this could be a problem but with the computer controlled crap I have no clue how to fix it besides swapping distributors. If anyone has any inputs to help fix the probs or any insight for a beginner with WinALDL please pass it along. Thanks for your time and help.

Mike

JPrevost

Except for the duration on the cam you've got a similar setup. I just don't know what heads you're using.
What is your location?
If it's idling ruff then check to make sure each cylinder is firing. Does the car feel ruff and shake the whole car even when you give it some gas? If so, double check all your spark plugs, one plug could be fubar and causing the issues. Also BLM/INT shouldn't change much, only the INT. The o2 values are suposed to bounce up and down. If you notice the o2 volts are down low below .300 for more than a few frames then the BLM should move! So long as the o2 is "swinging" around .450 you're fine. How far down is the o2 sensor from the motor and is it a heated sensor or just a 1 wire?

Low C1500

Are you running the 747 ecm?

Sounds like everything is working as it should with your setup. Its just what mine did a while ago (really low O2 then really high O2). Your going to have to change some "fueling" settings.

If your just getting into prom burning, I wouldn't get too concerned too fast.

Try reading RBobs fueling paper:

http://www.diy-efi.org/gmecm/papers/747fuel.txt

I tune industrial controllers for a living, and let me tell you there alot simpler than these ECMs. There are just so many varibles to take into account when trying to tune just how fast the fuel gets delivered and how fast the ECM responds to an O2 error.

And a 3 wire heated 02 sensor will be more stable in it output.

JPrevost

He's running an 8746 ecm, not the 7747. No difference really except for the IAT and highway mode already enabled.
As for the o2 readings, don't worry about it. Just make sure the ecm is in closed loop and BLM learn mode (winaldl will tell you). With an update speed of only 0.8 frames per second you can't expect to see the o2 swing back and forth, this is why I burn my own eproms. I've got the o2 cross-counts outputed and this helps a LOT to make sure everything is working correctly in closed loop. You can do this too if you got the burning equipment.

btcamaro

will winaldl support the 7730 ecm? I downloaded it but the ecm is not in the configurtion options.

therealalkybird

sorry it took me so long to get back, I have been busy. Thanks for your time however. My location is in Colorado Springs, unfortunately. The engine will occasionally run rough enough to shake the whole car only not continuously. The engine tends to vibrate the car for a minute or two then smooth out for a little while, then go back to vibrating again. I thought that it might be a timing problem yet I have no indications of knock and the only time that it feels better is when the timing is so far retarted that the car will fall on it's face anytime the pedal is depressed. The plugs are fresh, as are the wires. None have burned through. I am going to replace the plugs again just to be sure. I know the firing order is good. The O2 sensor wire is almost right against the block but it is either that or run it directly across the headers. Also it is a one wire. The INT sadly enough doesn't change as much as the BLM. The BLM ranges from 135 to 109. It will idle at 109 when it is warmed up and will only raise under WOT when they both set to 128 (I have been told this is how it should be as that is open loop) or when there is high load and low speed, then the BLM raises. The BLM doesn't really move even if the O2 voltage is below .300. The only thing that I can think of is that my 1228746 might be taking a dump. I don't get uniform ECM pulses when looking at the flag data. It is pretty constant but then you will have a few that will skip.