7730 tpi shutting down

[misterpat]

Hi!

Finally got my TPI project running and I'm experiencing random shutdowns. I ran TunerPro RT in record and toward the end of the log, it seems several readings go way outa range then it shuts down. The only thing I don't have hooked up is an O2 sensor as I don't have an exhaust yet.

Anyone mind taking a look at this log file? I have a feeling the PCM is bad. But before I buy another, I wanted to get another opinion.

Thanks!

Pat

[84Elky]

You need to post an exported .csv or .xls file from TPro. The .xdl is useless without your XDF file.

[misterpat]

Sorry, didnt realize that. Hows this?

[84Elky]

ECM not bad. Can beat a 7730 to death physically and electrically and they keep on ticking. You're running this bin based on your PROM code 0x23B: "AUJP 90 F-car 5.7 TPI auto". But with TPI, you can't run in closed loop (CL) without an o2 sensor. Engine idling OK until it goes into CL at sample 658. Once in CL, the o2 sensor is trying to adjust fuel BPW based on sensor's voltage readings. Can't be done without sensor connected; so should turn on the CEL, throw an o2 code 13 and go into limp-home mode. Here's the error code in your situation:
--Error 13: Occurs with an open ECM-to-sensor circuit, or along with other conditions when o2 voltage is between 300 and 600mv for 30 seconds

At the point of error, if you don't have an AUJP or other TPI MEMCAL in the ECM, you're toast and engine will not run properly or at all. Will also have later knock sensor issues. Now what I don't understand is why code 13 is not set in the log because it should be.

You also might want to check your VE table. It seems a bit rich at 650 RPM idle with 2.7-2.8 BPW ms unless you're running a hot engine. If running a 305 with this stock 350 BIN, definitely rich.

HTH

[misterpat]

Thanks for looking at that, 84Elky. I was away for the weekend and just getting to this. So what your saying is the memcal is the issue as its not going into limp mode and not setting code 13? The engine is a 355 sbc with Dart SRP heads. Everything else is stock. But your right, it seems rich to me as well. Hoping once I get the o2 sensor hooked up I can get some better logs on it.

[84Elky]

Thanks for looking at that, 84Elky. I was away for the weekend and just getting to this. So what your saying is the memcal is the issue as its not going into limp mode and not setting code 13? The engine is a 355 sbc with Dart SRP heads. Everything else is stock. But your right, it seems rich to me as well. Hoping once I get the o2 sensor hooked up I can get some better logs on it.

What I meant to convey:
1. It should be going into limp mode, and if you do not have a TPI MEMCAL (preferable AUJP), it will not run. For example, if you have a MEMCAL for a 6 cyl or a carbed v8, all the parameters are incorrect for your engine so it can't run, or at least not properly. What do you have? Look at the info on the back of the MEMCAL. If you can't read it, remove it from the ECM and pull off the blue cover.
2. I don't understand why your log does not show Err 13 being set., but it's not worth running it again to find out until you get an o2 sensor, unless you want to. If done, then after it dies, short pins A/B of the ALDL connector with key on engine off. Should blink out 13 and maybe other codes.

PS --
Not mentioned in the first post -- Once you install the o2 sensor, you might consider following the procedure for setting the TPS voltage (and IAC). TPS voltage is presently 0.71v and above GM spec of 0.54v. Some will set it up to about 0.65v. But know that 0.78v is the critical value. Anything above that and the code assumes the engine is not idling. Not good. Also related to proper idling and determination of other issues is the absolute need for a VSS. Some try to run without one, but many things are affected if not installed (most related to how o2 sensor readings are interpreted because VSS pulses are used to determine if above or below 15 MPH for may o2 related decisions -- all of which affect BPW calculation).