Innovate LC-1 wide band controller

[usedgeo]

Well after thinking about it for way to long I finally wired in the LC-1 wide band controller that can simulate a narrow band O2 sensor. I ran a ground to the bolt on the bellhousing that has may other grounds on it.

http://www.innovatemotorsports.com/

I ran it a couple days at the 14.7 A/F ratio. I hooked a computer up and tried to lean it out a bit. I thought it appeared to program. I drove the car and it just kept getting leaner until it barely ran. I managed to get home but the car was missing and the catalytic converter may have been damaged .

I tried repeatedly to get the controller to reset to factory defaults and re-calibrated the sensor. I finally put the OEM O2 sensor back in. It took over 30 miles to trim back to running decent. I lost a little over 2 mpg off a 600 mile tank with this episode. I was only making about 45 mpg when it was running too lean. Probably the scangauge could not be trusted in these conditions though.

There is a bit of discussion of people having problems with these on the Forum at the Innovate web site. The problems are usually resolved. As you may know my under hood temps run a bit high but I don't think that was the problem, well maybe.

As the engine gradually came back in to trim I could experiment with the way it ran. I am convinced that there is almost no additional leaning that can be done to my Saturn if it is running IAT over 160 F.

It was apparent from the way my head and spark plugs looked that it was already running reasonably lean.

I might have a slightly used LC-1 for sale soon. There are other things I would rather do than mess with this. The little Saturns get over 40 mpg out of the box. I think the factory did a pretty decent job of programming it already and I don't think I am going to gain much pursuing this line.

I need to think about it a few days and maybe take another shot at it. I posted a PO432 code once. I don't want to ruin a good catalytic converter for no good reason. I posted no codes today and did not have that odd periodic combustion in the exhaust system anymore but I need to keep my fingers crossed. Even when the engine had trimmed back far enough that it was not missing but was still running lean it would get an intermittent pulse of combustion in the exhaust system.

Well that is today's story. I might change it a bit tomorrow.

[lovemysan]

When I read my plugs I think I could go a tad leaner with no ill affects. To bad the LM-1 proving not much use. Also I find the sweet spot to be 168-170f indicated by the scangauge to be the FE sweetspot. But let it be known that the iat sensor is not always accurate, my 2 seperate thermometers indicate the the iat sensor is 98% of the time a pessimist by 20f. So when the SG indicates 168 the engine is actually ingesting 190f.

I also think that the IAT temp sweetspot changes with load. I think that with more weight and speed(800lbs load @65-70mph) the car prefers a slightly cooler temp around 150-155f. I think that with an empty car 170-175f @ 50 mph is more efficient. Of course what actually happens in those scenarios is the opposite.

[cfg83]

usedgeo -

I'm very sorry to hear this. I hope your Cat is okay. Could it be that your second 02 sensor was fried (would be cheaper than fixing the Cat)? Would it get fried in extreme lean-burn? If the second 02 is not working, then I think the PCM would be switching back and forth with the A/F ratio.

CarloSW2

[cfg83]

lovemysan -

Originally Posted by lovemysan

When I read my plugs I think I could go a tad leaner with no ill affects. To bad the LM-1 proving not much use. Also I find the sweet spot to be 168-170f indicated by the scangauge to be the FE sweetspot. But let it be known that the iat sensor is not always accurate, my 2 seperate thermometers indicate the the iat sensor is 98% of the time a pessimist by 20f. So when the SG indicates 168 the engine is actually ingesting 190f.

I also think that the IAT temp sweetspot changes with load. I think that with more weight and speed(800lbs load @65-70mph) the car prefers a slightly cooler temp around 150-155f. I think that with an empty car 170-175f @ 50 mph is more efficient. Of course what actually happens in those scenarios is the opposite.

Are the IAT temp sensors side by side in the airbox? Did you do a test where you dipped the sensors in hot water for comparison? I think I will need to copy you and get a kitchen thermometer for comparison.

I think the IAT sensor is extremely location dependent. That is to say, when the ECU/PCM software was being created, the engineering assumption was that it was in the intake tube leading to the airbox. Even if the IAT is off, so long as the IAT you and I are using behaves the same as the IAT that the Saturn programmers were using, then degree of error may not be important. Also, the sensor is unimportant to the ECU/PCM after the car goes into closed loop.

What I think is interesting is that the old plastic ECTS (water coolant) and the IAT sensors appear to be identical in Saturns (same part saves money). This is why the ECTS sensor would corrode over time in the hot coolant, because the covering was made of plastic, just like the IAT sensor.

I *think* I am using a leftover brass IAT sensor in my airbox. The metal should transmit/convect temp changes faster than the plastic.

CarloSW2

[usedgeo]

Sorry about the false alarm.

When I got in to the house I remembered the code as:
PO432 Downstream catalytic converter efficiency below threshold.

The code set again today and I took more careful note. It was:
PO452 Natural vacuum leak detection pressure switch stuck open.

That is a lot less significant. Maybe I left the gas cap a bit too loose. In any case I don't think this will be a serious problem.

Back to the LC-1. I will probably download the newer revision of the software and try it again. Do USB to Serial converter cables have a baud rate one can select? It communicated but seemed to mix things up a bit. One of those Eagle research circuits might be a simpler solution.

My mileage is back on track again.

I have seen that 1986 Chevy Chevette heater cores are quite cheap. I have been thinking about making an intake air heater from one of those. This would give more stable heat in perhaps the right range.

[lovemysan]

Originally Posted by cfg83

lovemysan -



Are the IAT temp sensors side by side in the airbox? Did you do a test where you dipped the sensors in hot water for comparison? I think I will need to copy you and get a kitchen thermometer for comparison.

I think the IAT sensor is extremely location dependent. That is to say, when the ECU/PCM software was being created, the engineering assumption was that it was in the intake tube leading to the airbox. Even if the IAT is off, so long as the IAT you and I are using behaves the same as the IAT that the Saturn programmers were using, then degree of error may not be important. Also, the sensor is unimportant to the ECU/PCM after the car goes into closed loop.

What I think is interesting is that the old plastic ECTS (water coolant) and the IAT sensors appear to be identical in Saturns (same part saves money). This is why the ECTS sensor would corrode over time in the hot coolant, because the covering was made of plastic, just like the IAT sensor.

I *think* I am using a leftover brass IAT sensor in my airbox. The metal should transmit/convect temp changes faster than the plastic.

CarloSW2

I've tried the IAT in the airbox top beside the meat thermometer and then in the intake tube itself beside the oven thermometer. Same results in both locations and same behavior.

[cfg83]

lovemysan -

Originally Posted by lovemysan

I've tried the IAT in the airbox top beside the meat thermometer and then in the intake tube itself beside the oven thermometer. Same results in both locations and same behavior.

Ok, then that's !

CarloSW2