FreeScan

[wcdeane]

Just hooked up a portable to my SE, and performed a couple of FreeScan runs. One was a dead cold start, and the other was a warm start, both standing still. Much to my surprize, I find that the program is picking up only three columns of data. RPM. coolant temp, and battery voltage. I have the three leads going to the ALDL -- one going to ground (terminal A), one going to 12V (terminal F), and the third going to terminal G, which is the data terminal. I think that this is the correct configuration. Any ideas as to what might be going on here? Might I have a bad ECU? I have had that suspician because of the car's terrible performance. It runs fine for the first few minutes in open loop. Then things go to hell when I sence that it goes into closed loop.

Any help would be greatly appreciated.

[cnh1990]

Sent you a schematic of the aldl cable via email.

[MikeyRide]

Dumb question: did you check off the "Force Data" (I think that's what it says) box on Freescan?

[wcdeane]

Not a dumb question. Ya know, I suspected that, but I didn't do it because of the way this feature was stated on the download page. It is stated as though it were some kind of option "If you do this then that". It didn't say that "you must do this to make the software work". Ah well, silly me. I'm at work at the moment. I will certainly try that when I get home. Thanks for the comment. Boy, do I feel dumb -- or at the very least, not very intrepid.

Question: I have never used a 10K resistor to put my ECU into the diagnostics mode. I have always just used a wire to create a dead short across terminals A and B. Do I need the 10K resistor to put it in the diagnostics mode when I use the "Force Data" function in this software?

Thanks, Mike.

Gratefully, Walt

[wcdeane]

Dah! Press the "Force Data" button and guess what -- you get engine data, and lots of it. Thank you Andy Whittaker!! That log file function is the perfect diagnostic tool!

All that log data tells a story. Thanks to FreeScan, I think that I have finally nailed down my problem. It seems that except for when the engine is cranking during start up, I have no spark advance -- zero, zippo, nadda. That clearly explains the unspent fuel in the exhaust, and the poor engine performance.

Other engine data indicates that the ECU is getting reasonably good signals from all the sensors, including the Crank Position Sensor. There may be a slight ptoblem with the coolant temp sensor, as it was sending out a goofy signal late in engine warm up. Anyway, according to the Lotus Service notes Manual, the Electronic Spark Timing (EST) function is incorporated in the Mem-Cal chip. So, my first move is to replace/upgrade the Mem-Cal chip. Oh, Darn. I was going to do that eventually anyway. Let me know if you think I'm on the wrong trail.

Thanks for the help Calvin and Mike! Stay tuned (no pun intended). I will let you guys know how this comes out.

[scruff400]

I WANT ONE!!!!!!!!!!!



(griffith)

[cnh1990]

Forward from Reed:
I think you *might* be on the wrong trail. Spark advance would be
controlled primarily by the MAP. Check the MAP sensor signal. Make sure
the vac line from the intake runner on #4, to the MAP sensor is intact and
unmolested. I you change the PROM prior to solving the problem, you'll
never know if it was an improvement or not, or if so, how much. This is
because the original problem would remain. ..............Reed

[wcdeane]

Remember that the diagnostic software indicates that all the sensors, including the MAP sensor are sending typical signals to the ECU. I have confirmed this by comparing my FreeScan log against a log coming from a car that runs properly. Remember also that it is not the MAP that sends the proper “advance” signals to the Direct Ignition (DI) -- it is the ECU, and more specifically the MemCal chip. If the ECU is getting good information from all the sensors, and there is no spark advance (none at all), it would seem to me that it would be one of four things – the DI module or the MemCal, or something in between the two, like the wiring or the ECU itself.

Here is what I know as of this morning, 8/8. I removed the MemCal yesterday, and low and behold, it was an S4Sm MK5 chip dated July ’98. So that’s cool. I’m going to eliminate some other things before I replace that. Last night I had the DI module bench tested, and it passed. I replaced it while I had it out. That leaves the wiring and the ECU. The wiring is cheep, but it’s a pain in the ass. I can get the ECU today for about $175 US and it’s easy to do, so the ECU is next.

All this may seem foolish to some, but when I consider what I have learned through this ordeal, and what I’d be paying someone else ($65/hr. or more), these small incremental costs are nothing to me. And thank you for your cautionary message on the MAP. I was on that trail for some time when this problem started. I even replaced it. If things don’t go well here, I could be back on that trail again soon.