Jeep with old Howell kit - it's WAY rich at lower RPM...

[lionelhutz]

I have no idea what Rostra sensor you're using. The '7747 requires 2000 pulses per mile. You feed the AC sensor into the Dakota box then after setting it up correctly you'll get a 2000PPM signal from the Dakota box to feed the ECM. The AC sensor has 2 wires and they go to the 2 sensor input wires on the Dakota box. It doesn't matter which goes where UNLESS one of the wires hooks to something else in the Jeep and is grounded by that something else. If you have a 40 pulse per rotation AC sensor in the transfer case then you can feed that signal right into the Dakota box for conversion to 2000ppm.

[DanInTX]

Hi 'lionelhutz' - thanks for the reply!

The Rostra thing I am using is a two wire magnetic sensor that comes with four magnets that presumably go on the driveshaft. It is part number 250-4165 - Summit sells it for $25.97. Since I have a Jeep that gets banged around a lot, I plan on putting the magnets on the front output yoke on the transfer case where they should be protected by the skid plates. I believe it works just like any other two wire magnetic sensor. I also believe that by using two magnets I get the 2000 PPM signal that the ECM wants, although as I think about it, it may only need one magnet. In any case, I can place up to four magnets and get several choices. Plus I have the option to use the 40 tooth wheel already in my transfer case.

I have never had luck with the Dakota thing, but yesterday I discovered that it is probably not going to work without the wire actually going to the ECM. Who knew.

I called the Dakota guy - he gave me a number of ways to set it up. One option (I believe - I'm not looking at my notes) is to set all the switches to 'off'. Then the AC signal from whatever input I have (2000, 4000, 128,000) will be converted one-to-one to a DC square wave, which should be what I need. For that reason alone I like the idea of the Rostra thing with two (or one?) magnets. If my speed is off (which it will be - my tires and my gears are different) I can adjust it - the converter has little "up" and "down" buttons to adjust the output.

Have you ever used the Dakota thing? Did it work for you? What sort of settings did you end up with? Or how do you run your VSS?

I am going to add that wire to my harness tonight and try to put all the pieces together - I'll post when I get it working and let everybody know my "recipe".

Thanks again!
Dan.

[lionelhutz]

I doubt either of those speed sensors will give the 2000ppm signal the ECM needs. That'd only happen if your driveshaft is turning 2000rpm at 60mph and your use a single magnet. You will have to calibrate it via a conversion module.

I've never used that Dakota Digital box. But, it's more or less an improved DRAC module. It should work with your 40 tooth wheel and a stock VSS just fine.

Rostra isn't very clear in their instructions but I wouldn't be surprised if that setup produces a square wave as the magnets pass. I do have a Rostra cruise control and it takes a DC square wave signal. I'm currently feeding it from the 4000PPM VSS output of my PCM which is also driving my speedometer.

[DanInTX]

I've tried to figure out just what type of signal the sensors produce. It seems that there are two kinds of 2-wire sensors and maybe one or two kinds of 3-wire sensors. The 3-wire ones don't matter in this case, so for the 2-wire versions:

One type, the regular kind on setups using a tone ring (or reluctor wheel, or several other names for the same thing) are the "reluctance" sensors. The teeth from the reluctor wheel will induce an AC voltage as they go by the magnets in the sensor. Voltage goes from above zero to below zero (of course, that's why they call it AC), so either wire conducts the same signal, just 180 degrees out of phase, but who cares about that.

The other 2-wire sensor - mostly for ABS control - is the "active sensor". It also uses a type of tone wheel, but the key difference is this: the tone wheel in this case has little tiny magnets in place of the teeth, and the sensor has no magnets. One wire to the sensor carries 12V; the other wire carries a square wave signal whose frequency varies with the speed of the tone wheel.

The 2-wire VSS in the GM setups we are using (the older ones - don't know about the new ones) are the first type - "passive" sensors which make an AC signal.

So like you said, the Dakota Digital signal converter is a fancy DRAC, which was used to turn AC into DC (not to be confused with the really cool band whose songs have the very best intro's). As I understand it, various DRACs were used to adjust the output to match a particular vehicle's wheel size, gears, etc. - they just weren't easily adjustable themselves (or affordable, or even available) - so the D.D. converter is really a universal DRAC. I hope.

As it turns out, my driveshaft turns at 2279 RPM at 60 MPH, so one magnet should get me pretty close, at least close enough for the ECM to know whether I'm moving or not.

For my speedometer I use a Ford 2-wire passive sensor: I swapped in a Ford 8.8 axle which has a large tone ring (maybe a million teeth? Never counted them...) bolted directly to the ring gear. This signal goes to a VDO speedometer which is highly adjustable and gives me a good speed reading.

Now here's the rub: Had I paid a little more, I could have gotten an AutoMeter speedometer which would output a signal to my ECM, and all this would have been moot. But I have the VDO one which doesn't do that, so here I am.

I did some wiring tonight but didn't get finished, so maybe this weekend I'll post either a success story or I'll set my Jeep on fire.

Dan.

(Now, all of that sensor stuff may be true or it may be crap. I got it off the internet, so it has to be true, right?)

[1project2many]

while datalogging, I happened to to glance over at the "dashboard" and noticed a curious thing: when driving at about 30-40 mph, the BLM and INT needles would slam down to minimum levels when I take my foot off the pedal

Look to see if the BLM cell number changes. The BLM Cell is a sort of "memory location" for stored BLM data. If you don't spend much time in a particular cell then the data in that cell may not have been adjusted by the ecm.

I believe it works just like any other two wire magnetic sensor.

Except that not every magnetic sensor with two visible wires is a two wire sensor. If you cannot find info then you should measure the sensor output as the magnet passes... look for a/c current.

I also believe that by using two magnets I get the 2000 PPM signal that the ECM wants

As previously mentioned, unless your driveshaft turns at the right speed (1000 revolutions per mile) the signal will not be calibrated correctly. With two magnets your driveshaft will produce a 4558 pulse per mile signal. I would recommend the 40 tooth wheel and a GM DRAC designed to work with the GMECM / 40 tooth wheel combination.

various DRACs were used to adjust the output to match a particular vehicle's wheel size, gears, etc. - they just weren't easily adjustable themselves (or affordable, or even available)

DRAC modules (and the second gen version, VSSB) were and are easily adjustable. And once information got into the wild (this happened some time around 95) anyone with internet access could make the necessary adjustments. Look for drac2.pdf by fellow gearhead-efi member Kevin Vannorsdel. There's a copy on gearhead-efi. The DRAC module itself is fairly easy to find. Astro vans, S10's, and pickups and vans used into model year 2001 had them. They're selling for ridiculous money on Ebay but local yards should be more reasonable.

maybe a million teeth? Never counted them...

I know what you mean. Somewhere around 850,000 teeth my ADHD seems to kick in. It's tough to stay with it after that.

FWIW the decel conditions can be improved without a speed signal. The speed signal will really help the ecm keep track of how and when to control idle speed. To improve decel you likely need to work on reducing fuel at high vacuum. This is where computer timing will help as you can really ramp up the advance in decel. Most mechanical advance systems don't have as much flexibility.

(Now, all of that sensor stuff may be true or it may be crap. I got it off the internet, so it has to be true, right?)

Right. Everything posted on the internet is true. The problem, it turns out, is that the internet is multi-dimensional. In order to determine the relative truth of any statement to your particular situation it is perfectly acceptable to ask a another 'net user from what universe he or she is posting.

[DanInTX]

There are lots of theories on the number of universes that exist. The number ranges from one to infinity - most physicists lean toward the infinite number, which, by the way, suggests that there exists somewhere a universe exactly like the one we live in. Furthermore, given what infinity means, there will somewhere be an infinite number of universes exactly like ours. There will also be an infinite number of universes almost like ours, and of course infinite upon infinite numbers of universes very different from ours.

And that makes me wonder...

Somewhere there has to be a universe where there is a guy like me (except that he's rich and understands this stuff) with a Jeep that looks like mine but does not freakin' STINK so much at idle! But according to Max Tegmark (a highly regarded cosmologist) a universe like ours is 10 to the 10th power to the 115th power meters from us. That's a long drive. And the one with the good version of my Jeep is probably on the other end of that one.

That also means that if you encounter information on the internet, the author is infinitely likely to be from a universe where the information he provides does not follow the same laws of physics we know.

So that brings me to my next point...

In our universe, it turns out that the two wire magnetic sensor in the kit I bought does indeed produce an AC signal. I stuck four magnets to a drill chuck and squeezed the trigger. With both leads of a digital VOM connected to the sensor leads, I was able to see an AC voltage. So far so good.

Also, by doing higher math (third grade at least - challenging for me, anyway), I calculated that with my tire size and gear ratio, 1000 revolutions of the drive shaft will get me nearly half a mile, and 2280 revolutions will go exactly a mile. So I have to conclude that one magnet on the drive shaft yoke will give me just over 2000 pulses per mile, close to what the ECM wants. So if my signal converter can convert an AC signal one-to-one to DC like the Dakota rep says, then the problem is solved. I'm going to try that. I will also try the same converter with different settings to utilize the 40 tooth wheel. I would actually prefer using the transfer case wheel since it has to be more solid than a drive shaft bolt-on thing.

And FINALLY to my two real questions...

(1) What can I do to reduce fuel at high vacuum? Would I adjust the VE table in, say, the first four blocks or so - 400 and 800 RPM at 20 and 30 Kpa? I usually can't get BLM readings in at least two of those cells anyway. I would even like to adjust maybe the first two whole columns downward while leaving the others alone - within reason, of course. (Remember, I would like to get this improved prior to my Jeep trip; after that I can take it off the road and work on electronic spark control.)

(2) Where exactly do I find the "BLM Cell" you mention? Do you mean the cells in the BLM History that show up while I'm datalogging, or is there a table in the bin that I can look at to see what the computer is storing as a BLM for that location? If the answer is 'b' I can't seem to find one. If the answer is 'a' my history doesn't have those low cells filled in (especially the 400 RPM ones, which is where I think the adjustment should probably be made). The idea sounds good - please give me a little (or big) hint on where to find the BLM Cell.

Thanks again to all who help - I'm learning a lot and my Jeep is reaping the benefits.

Dan.

[lionelhutz]

Did you try your test with the meter set to DC?

Modify the low MAP columns at the RPMs you want to change. No point only changing the 400 and 800 rpm rows if your issue is at 1500 or 2000 rpm.

[1project2many]

BLM cells are used to store correction data for a range of operating conditions. A BLM cell might be used to store the BLM correction for 1600 -2400 rpm. When the engine is outside that rpm range another BLM cell is used. BLM cells allow the ecm corrections to be applied in "blocks." If the engine tended to run lean above 2400 rpm, for example, the higher BLM values stored at upper rpm would not cause the ecm to richen the engine at rpm below 2400. BLM cell # is a data point provided in the datastream to allow you to determine which cell is being utilized.

It sounds like you might have problems other than rich idle. Decreasing VE values at higher vacuum during decel might help. The datalog can reveal the rpm range of interest. I suspect it is greater than 800 rpm.

I do not know how badly your jeep stinks at idle, but old grind cams and inefficient combustion chambers can work against you. The OEM's have invested many hours and dollars to design parts that are much more emissions friendly than some of the early iron. Some combinations just don't do a good job of burning all the fuel.

[DanInTX]

1project2many:

OK - I get it. I've been using the 'BLM cells' all along to change my VE tables. I make a chip, take a drive, record a bunch of data, and use the table that has the BLM history average to calculate changes for the VE numbers. I make those changes, drive some more, and do it again. I've done this maybe ten or so times, and my numbers are so much better now. On my first few runs the BLMs at the left of the table would stay at 108 - that makes me think the integrator was, like, 10 or 11 when I was driving, and it took a few cycles to get the BLMs to move above their 108 minimums.

[[ I thought you were referring to some other 'BLM cell' I didn't know about - maybe it was hidden or something. By the way, I have noticed that the instantaneous BLMs can sometimes vary wildly from the average ones. Under some conditions, if I have my monitor set to show it, I can see momentary values as low as 108 or as high as 146, yet the average still turns out to be 124 or something. ]]

Anyway, after my most recent run, all the numbers in the 20 kPa column are 123 to 124, as are all the numbers in the 400 and 800 rows up to 50 kPa. From 30 over to 80, pretty much everything is about 130 to 132, with a few places a little outside that range. Pretty good considering where it started. And these BLMs were collected using a VE1 table that ranges from ~32 top left to high 90's along the bottom. Prior to working on this, I had single digits on the left and values over 124 on the lower right.

I still think I may tweak the BPW (really BPC) a little more. It started at 181 and is now 195. Moving it up a pinch at a time has pushed my upper numbers to below 100. However, even though I have pretty much combined my VE1 and VE2 tables, I still keep a value of '5' in all VE2 cells, so at my upper RPM ranges and higher kPa areas my combined value can still pop over 100 (or the magic 98.6 ceiling, or whatever it is).

This whole thing is an exercise in what EagleMark would say "lather, rinse, repeat". I believe that my starting numbers were exceptionally dirty and needed a lot of cleaning. And they still need a lot of conditioner.

So I plan to do the cycle a few more times, and it should get closer and closer. And I found that 'smoothing' makes a drastic improvement in both appearance of the chart and in smoothness of operation. I am guessing I just haven't gotten done with the low end especially, and I guess this is partly because it's so hard to get BLMs in that area. So, as Churchill said, "Keep calm and carry on." Or more appropriately nowadays, "Keep calm and carry".

-----

Regarding the 'old iron' comment, I can't help but think my old iron is among the worst of the bunch. With a big straight six design, my engine has intake runners on both ends that are about three feet long, while the center two are about three inches. These numbers are slightly exaggerated of course, but not by much. It's amazing that the spark plugs look as similar as they do, although they are certainly not "carbon" copies of each other. (That's a pretty good pun, isn't it.)

I hear that AMC engines - six and eight cylinder alike - take a lot of timing before they start to detonate. I'm not sure what that says for the chamber design - clearly at 40 years old they are not modern. It is probably a polite way of saying they suck bad and my efforts will hit a brick wall pretty soon.

And I do have a modern camshaft - a low RPM torque thing. I really didn't notice a change until I put the larger throttle body on. I guess it all works together to improve efficiency. My limiting factor now is the pea-shooter intake manifold. Maybe when I change the distributor I'll put on a more modern intake from a 4.0L Jeep engine - people seem to think that is a very worthy improvement.

-----

lionelhulz: I just did the 'drill test' on my VSS again. Results are as follows:

With the meter hooked to AC: A voltage appears that varies both with the rotation speed (that's what I was hoping for) AND the number of magnets used (this makes sense too). At really low speed the voltage was small, like less than a tenth of a volt. At maximum drill speed - 2500 RPM (advertised - not sure what it was at 0.050 - another weak joke) the AC voltage reached about 1.1V. Variation in voltage was smooth and apparently linear (per eyeballing it - I don't have a scope).

With the meter hooked to DC: At zero rotation the meter said 0.000V. With rotation - any speed, any number of magnets, the reading varied randomly from zero to about 3 to 10 mV, plus or minus. There was no correlation with speed or number of magnets, and a steady RPM and constant gap between sensor and magnets still yielded the trace random voltage. My assumption is the drill, the magnets, or my wire layout caused a very small induced voltage, yet this voltage was not predictable or even large enough to be usable.

Conclusion: the 2-wire VSS that I'm using (and the common 2-wire VSSs used for most RPM sensors that we encounter - not the 'active' ones for ABS or the esoteric 2-wire ones that also exist) produces an AC voltage that varies with rotation speed and/or number of magnets (which is really the same thing in the end). Therefore, some sort of device is needed to 'condition' the signal (turn it into DC), hence, the DRAC or the Dakota Digital thing or a nice Autometer speedometer or a circuit in the cruise control box or whatever. So I'm headed the right direction there, for whatever positives it will get me. (Or really "positives" and "negatives" - another pun - ha ha.)

Dan.
Again.

[1project2many]

OK - I get it. I've been using the 'BLM cells' all along to change my VE tables.

Sort of. You've been using the value stored in the BLM cell to make changes. I'm talking about the cell numbers.

Think of a grid of buckets, each numbered. BLM numbers represent the fill level of each bucket (1/2 full at the onset). BLM cell numbers equate to bucket numbers. In your tuning steps you've been watching and using what could be one bucket, or possibly a small quantity of buckets in the middle of the row. During decel when the BLM value changes nearly instantly, you may be looking at a bucket that doesn't get adjusted as often. BLM's are long term corrections and usually change somewhat slowly. If you are seeing instantaneous changes in BLM values, you should be aware of the cell number.

I usually refer to the value which represents injector flow / displacement as the BPC. I believe that's how it's flagged in some of the GM documentation.

I know the engine you're working with, at least in a stock form, as I have a '78 CJ7 here that I've been using as a plow rig for years. It has no catalytic converter and it really doesn't smell that bad at idle. Your high torque cam may be causing some of the problem as the stock timing curve likely is not appropriate for the cam. The larger TB may also be part of the problem. Carburetors were often designed so the venturi(s) really aided in shearing fuel as it entered the airstream. The only way to get a similar effect from the TB is to adjust the blades so they are nearly closed at idle and minimize the airflow through the IAC. It's a real balancing act and may not be appropriate to try while you are learning other aspects of tuning. You could try manually advancing the distributor at idle to see if the smell clears up. Or maybe you did and I didn't catch it?

Oh, and please be careful with spark plug puns. They might seem secondary to the conversation but they have the potential to ignite a whole new discussion.

[DanInTX]

Now that makes sense. In all my reading I have never heard of accessing the 'cell numbers' - I was just using the BLMs from the history tables - and the average ones for the whole run at that. Would the values stored in those 'cell number buckets' maybe be the weird numbers (the ones that are so far off the average) under some circumstances, especially at the beginning of a log session? I usually go for 20 to 40 minute over a course that gets me lots of readings in as many cells as possible.

I understand that what the ECM uses is most often the average of the appropriate cell averaged with the ones surrounding it. I imagine this is why smoothing the table gives much smoother performance, which I have noticed in a big way.

What I don't get is where to find those 'buckets' so I can access the numbers in them. Is there a separate table that I can't find? Are the cell numbers right in front of my eyes and I am not recognizing them? Does it take magic?

Knowing that there are numbers in some areas that get stored and used but not modified frequently (and apparently not necessarily averaged with surrounding cells, maybe, for some reason?) pretty much explains why, if I look at just the right time, the BLM and INT needles jump instantly to their low limits. They don't slowly or even quickly move - the just appear there, and then they 'appear' back up at a more normal number when I move the pedal some. But how do I find these cell numbers so I can see what values they hold, and maybe change them? I am guessing they are going to hold values way over 128.

I read somewhere that whoever did the original hack of $42 named the BPC a 'BPW' and the misnomer has been carried on since then. At the beginning of my Scalar list there is something called BPW, but I am living under the assumption that it is really the BPC, and it is created by that really long equation. And that's the number I've been inching up in order to squish my VE values under the ~100 limit. And (tell me if I'm wrong, but I don't think so) I believe that the ~100 limit exists mainly in 1227747 - I hear numbers above 100 are allowed in other ECMs. When I would save a new VE table that had values over 100, I would open it again and find those numbers had been chopped to 98 or 99 point something.

Regarding the Jeep setup: it has a catalytic converter - has had one ever since I got it, although it's been changed a couple of times due to trail damage. Currently it has a high flow one that is supposed to serve up to 400ci. I can't remember if converters make exhaust smell worse or not, but it has smelled bad ever since I added fuel injection. I really don't remember how it was with the carburetor - the exhaust contained a variety of aromas including burned oil and antifreeze in addition to the perpetual too-rich carburetor smell.

Idle stench (and overall rich smell everywhere) existed before I put the bigger (4.3) throttle body on - that was one of the reasons I changed from the smaller one - I figured the small size may have choked off some air, and the ECM couldn't reduce fueling enough. It made sense to me, but it didn't work. It was also smelly before the cam change, plus it was gutless. With the cam change, it gained a few guts, but continued to stink.

One thing I haven't done is advance the base timing. I actually reduced it back to eight degrees. Several months ago I changed the distributor. It is another HEI unit with a fairly aggressive curve. I thought I was hearing detonation so I reduced the amount of advance. Turns out that some clips in my dash/cowl area would rattle when I accelerated (or decelerated) but not when I hit bumps. This sound was very convincing - it came from the right direction and sounded exactly like that "medium-high pitch marbles-hitting-glass-and-heavy-steel" group of rattles that detonation sounds like. With all the other noises in the Jeep, it faked me out. So I am going to re-advance the timing - maybe this will help some, along with messing with those 'cells' we're talking about.

Regarding IAC: I set my 'minimum air' to give me an idle of about 575-600 or so - it barely starts there - but my commanded idle is 700. With this arrangement my IAC counts at idle hover around 10-12 give or take. They sometimes trickle down to about 2, and shoot up a little bit as the idle varies. Is this an indicator of a 'fairly closed' throttle blade setting?


Thanks very much for your concern with my troubles, and all the help you've given me so far. Please feel free to keep helping!

Dan.

[1project2many]

I understand that what the ECM uses is most often the average of the appropriate cell averaged with the ones surrounding it. I imagine this is why smoothing the table gives much smoother performance, which I have noticed in a big way.

If the lookup values for VE do not always match a table location exactly, the ecm will use a combination of the cells on either side of the "in between" value. This combination is biased toward whatever cell is closest to the "in between" value. It could be called a weighted average. To that value is added the difference between INT and 128, and BLM and 128.

BLM cell number is a single numeric value usually found in the data stream. There are nowhere near as many BLM cells as there are VE table entries. The BLM values you are using now are what's "in" the buckets. The BLM Cell number is what's "on" the bucket. Knowing the cell number only helps you recognize why the BLM value may be changing so rapidly under certain conditions. After looking at data stream definitions, it appears BLM Cell # is not included with the 7747 ALDL data. So you will not be able to match BLM activity with a change in cell as easily. But generally speaking when you see those sudden and extreme changes it indicates a change in which BLM cell the ecm is using. As far as tuning the extreme edges of the VE tables, you don't need BLM to tune everything. It's just one of the tools that help.

The catalytic converter doesn't do anything magic. It causes unburned hydrocarbons and oxygen in the exhaust to react.
If the catalytic converter is unable to get enough air or if it cannot warm up it will not clean the exhaust. If you have an infra-red thermometer you can measuure the temperature of the converter compared to the exhaust in front of the converter. The converter should be extremely warm, and much warmer than the front pipe. If there's minimal temperature difference, try disconnecting a spark plug and letting the engine idle. The additional air from the now "dead" cylinder should cause the cat to light and begin the reaction. If the cat doesn't get any warmer then you just might have a failed converter.

I have often set throttle blade position with a 1/4" wide strip of paper. Open the throttle, slide the paper down into the throttle bore so the end is below the throttle shaft and the paper's wider face is perpindicular to the throttle shaft. Let the throttle close then try to pull the paper out of the TB. If there is a slight drag on the paper then the throttle angle is correct. Easy-peasy.

[lionelhutz]

The BLM cells simply create a table, likely 4 x 4 or 16 cells. Here is a thread with examples of what this table looks like for an $EE based PCM.

http://www.gearhead-efi.com/Fuel-Inj...9527#post59527


Each cell stores a different value so when you jump between cells the value can suddenly change.

The '7747 logging program can only put the BLM value into a table that matches the rpm and MAP values that are also read in the datastream. So, you get a table with the same number of BLM cells as VE table cells. But, that many BLM cells don't really exist. However, the value in the active BLM cell is constantly changing so during normal driving where you're not suddenly changing the throttle the way the logging program works is OK. You can shift from one area of the same cell to another area and get 2 "different" BLM values simply because the ECM is constantly adjusting it.

[DanInTX]

Thanks to both of you! This stuff is slowly becoming clearer to me. Both of those explanations improve my understanding of how this works. Too bad my ECM doesn't include the cell number. However, knowing more about this idea explains why I see big jumps on my TunerPro 'dashboard'. It's hard to do while driving, but if I look at the INT and BLM digits, they will sometimes jump in a BIG way, mainly at low speeds and idle and at zero to low throttle positions. Sometimes these numbers appear in my data tables (the 'most recent' versions; not the 'average' versions) and sometimes they don't. Also, I will sometimes see numbers in the monitor (the data thing with all the lines) that don't show up in the log tables. For instance, at those same speed and throttle conditions, the integrator will dive straight down out of bounds and try to drag the BLM with it, and then it will shoot back up to where it was (and the BLM follows). These values never appear in the tables, but by clicking on the lines, the integrator will show a SUPER LOW value - I am guessing that this is a peak into those cell number values.

So, all of this is food for thought, as well as the ideas about the converter. I know how it works, but I never imagined it wasn't staying hot enough to work. On the other hand, I no longer have the AIR system (it came off when the fuel injection went on) but maybe it really did help.

On a brighter note, I now have a setup with a working VSS. I tried both the driveshaft stick-on deal and the transfer case 40 tooth thing. Both worked, although with the transfer case version said I was going 100 when I was really going 25. I think that's a simple switch change - I'll know tonight or tomorrow.

Does TunerPro5 work on operating systems newer than Windows 7? It seems like early on when I first got it, something in the directions said use 7 or older. I have a laptop with 7 on it - it's old and it is about to crap out. I can use whatever OS I want - I just want to make sure this program will work with it.

Again, thanks for all the help. I'm back to looking over data now...

Dan.