LM-1 Test Results/Diagnosis (Pic Heavy)

[EZ Gruv]

Hi all, I was finally able to do some testing with a borrowed LM-1.

This is my 77 Type IV 2.0L FI

Alright, here goes. There will be a brief description and a chart for each section.

Before testing I did a 20 minute warm up jaunt on the freeway.

Test 1: Idle
Its hovering in the 16 range, which according to Ratwell's conversion chart is lean.



Test 2: 15mph
Rocking right at 14.5ish, which seems like a happy place



Test 3: 25mph in 2nd gear
About 14.8 I'd say. The spike on the end is when I let off the gas.



Test 4: 25-30mph in 3rd gear
A bit under 15 once getting into 3rd gear. The spikes are shift points, the final spike is letting off the gas



Test 5: 30mph
14.5ish



Test 6: Going up a local hill, medium grade
Right around 14



Test 7: Long sustained hill Going through all the gears
Gets richer when I get to the higher RPM range of each gear. Settled about 13.5ish



Test 8: Fast Downhill
Once I got going, it read in the 30s. Not sure what to make of that.



Test 9: Idle
Another idle test. 16-17 range, still pretty lean at idle



Test 10: 15mph
Right at 14



Test 11: 25mph
Pretty steady except when I feathered the throttle



Test 12: 35mph
14.5



Test 13: 45mph
Spike at shift point, just under 14.




So, what say you??
How concerned am I with the idle leanness?

[bretski]

Looks pretty darn good to me. My idle is towards the lean side as well, as my engine runs smoother that way. I need the extra air up here in Colorado.

[EZ Gruv]

Yep, my idle is pretty smooth.
I am quite pleased with my test results at this point.

[chitwnvw]

EZ, where are you putting the sensor?

[EZ Gruv]

Tailpipe probe.

[chitwnvw]

Tailpipe probe.

You just inserted it up the exhaust pipe? I know on TS they get all worked up on placement.

It looks like you can buy an LM-1 for 200 bucks or so on ebay, might be a good thing to go in on and share in the area.

[EZ Gruv]

Yep, it has a special tailpipe attachment.

[Bleyseng]

I would say the lean idle is because you are using the tail pipe probe. The "bung" puts the O2 sensor way up away from the tail pipe so no free air slips in to distort the readings which I suspect you are getting.

[airkooledchris]

I have the bung and the tailpipe connector and as long as you don't have any leaks, the numbers I saw were nearly the same. (not enough swing one way or the other to say for sure it made a difference)
This could also depend on the muffler itself.

that said, the empi muffler is starting to crack now just after the bung where the muffler connects to the extractor (sorry if thats the wrong term, its a two piece system) - and now my tailpipe readings are off from the bung.

so which do you prefer, the pipe or the bong, er bung?

[Amskeptic]

I have the bung and the tailpipe connector and as long as you don't have any leaks, the numbers I saw were nearly the same. (not enough swing one way or the other to say for sure it made a difference)
This could also depend on the muffler itself.

that said, the empi muffler is starting to crack now just after the bung where the muffler connects to the extractor (sorry if thats the wrong term, its a two piece system) - and now my tailpipe readings are off from the bung.

so which do you prefer, the pipe or the bong, er bung?

Roach, err blunt. . . I mean blung.
Colin