I have performed a MAF Swap in my 92 Chevy K2500. I have worked out the electrical and ads stuff with the with Dimented24x7. I am including my bin and the adx file for TunerPro.

Here are the specs on my setup:
4 Bolt Main 400 Bored .60 over=413
ProComp Aluminum 190cc Intake 64cc Combustion Chamber 2.02 intake/1.60 exhaust
Full Roller Rockers 1.6 ratio
Holley Pro-Jection Throttle Body Injection Manifold
COMP Cams Xtreme Energy 12-262-4 – 114 LSA, .464 intake lift, .470 exhaust. With the 1.6 rockers the final lift at the valve is .495 intake/.501 exhaust
Bored Out GM Small Block Throttle Body flows 750 cfm
90hr/lb 454 Injectors @ 21 PSI
NV4500 5 Speed Manual
255gph fuel pump
New GM Distributor
Headers
COMP 981 Valve Springs
COMP .080 7.2 Pushrods
SCAT 400SBC Cast Crank
ProComp 5.7 I-Beam Rods rated at 550 HP
9.5:1 .60 over SpeedPro Pistons
EGR Disabled and 160 thermostat
Heated NB 02 and Wide Band 02

This is my first tuning adventure and it is kickin my butt. I am messing with stuff but there are some problems that are killin me.

1st My idle goes up to 1500 like clockwork when I push in the clutch until the vehicle comes to a stop. If I am coasting long enough the idle will start moving between 1500 and 900. It hangs up there until I have been at a stop for about 4 seconds.

2nd The AFR's aren't where they are supposed to be I think. At idle they are showing 11-13. As soon as I touch the gas they bump up to 13.5-15. Even cruising yields 14.3-15.4. When I floor the truck it goes up to about 17/18 and after about a second they come down to about 14.3. I can't get them to richen up anymore than that.

It has decent power but not what it should I think. The truck in 5th wont break 96 on a flat highway but put it in 4th and it will accelerate.

Anyone at all I am all ears as I don't know what I am doing but I want to get this thing running right before winter really comes on.

Thanks everyone

 

You need to command open loop by setting the minimum coolant temp to 200 and then set the open loop afr table from 44degreesc and up to 12.8 across the board and log idle and a short low gear drive. make sure the wideband mirrors the commanded ratio. The spark table looks like its a table from a 305, you will need to hand edit them. But for now, the closed throttle spark advance needs to be smoothed out in the kpa areas that your engine idles at to corrall the hunting idle. Make sure the MAF table is the correct one. a b body lt1 maf is smaller than the f body lt version and ls models are all there own. the table looks to be one from an f body. Some stuff to check and focus on. HTH Essentially, you have to correctly "calibrate" the system so you can tune.

Chris

 

All the stock codes based on the $0D all do that with manuals. My vortec PCM (also based on the $0D/0E, etc.) did that as well before I patched it. The idle will hang until it hits closed loop idle when you come to a stop. I added tables to allow for the idle to touch down smoothly when a stick is in use. These basically decay out the added idle speed/throttle follower airflow so the idle smoothly comes down rather than hangs and suddenly drops.

As for the second issue, it sounds like the MAF tables are mis-calibrated to the sensor. GM has a whole butt-load of different sensors, so the table may need to be re-calibrated. Its not hard to do, and only has to be done once.

Later, I'll post up details on how to fix these.

 

I took a look at your bin, and it looks like you do not have the throttle follower reduction enabled. Go to the min closed throttle follower IAC TPS reduction table and try the values I have shown in the table attached. This should reduce the T/F action as you come to a stop.

 

Now, the way to tune the MAF is as follows. You need to run the truck at varying loads so you get a broad range of airflow rates and AFRs. The key is to make sure the engine has a chance to stabilize at each load and reach steady state, or the results will be meaningless.

For example: you might start off by just driving at a constant 30 MPH. Hypothetically, the MAF could read 4500 Hz, and the actual AFR could be 16:1. If your desired AFR is 14.7, this means that the MAF is underreporting the airflow by about 8.8% in this example.

To correct this portion of the table, you would then go to the cell or cells closest to 4500 Hz. Say that cell currently has 25 grams per second in it. From the test results, the actual AFR was 16:1 while your desired AFR was 14.7:1. In this case, you would multiply the entry at 4500 Hz by 16/14.7, or 1.088. The new airflow at 4500 Hz would then be 1.088 x 25 grams/sec = 27.2 grams/sec.

You continue this way by running the engine at low to increasingly high loads and observing the reported AFR in the datalog to determine if the MAF is reporting the airflow correctly. You then apply the corrections to the corresponding entries in the MAF table and then smooth the curve back out again. After that, repeat until the AFR is within a few percent of your desired AFR. When you are done, the finalized MAF flow curve in tunerpro should be a smooth parabolic shape regardless of the corrections made. If it has kinks or humps/bumps in it, then there is some other effect throwing the fueling off.

Remember, in order for your results to be valid, the engine must be allowed to reach steady state for at least a few seconds. If the load is varying rapidly, then your also having the fueling dynamics coming into play as well, which will throw everything off. The MAF MUST be tuned under steady state or as close to steady state as possible. You must also know both the actual reported AFR and desired AFR, and the AFR must be steady. When your tuning, you may want to set the entire open loop AFR table to 14.7:1 at the higher cool temps and also set the PE table to a constant AFR across the board, like 12:1 or so. Or, you could set the open loop AFR and PE AFR to 12.5:1 at all cell entries. Both will work. This way the AFR is steady under normal driving and in PE. Lastly, you must also lock the BLMs at 128 and disable closed loop when tuning the MAF with a wideband so the PCM does not try to apply corrections. Locking the BLMs can be done by setting the upper allowed limit and lower allowed limit for stored BLMs to 128. This will reset all the BLMs on the next restart.

Lastly, if you have the wideband hooked up to the PCM, the wideband calibration table must be set up to match the widebands output, or the reported AFR will be off. I can give you some help with this if you need it.

 

Also, which MAF sensor are you using? The entries in your MAF table look kinda low, which would explain the lack of power (running lean).

 

Ok so I fell off the face of the earth there for awhile but I am back. I am just reading this stuff.

I put in the throttle Follower Action numbers.
I worked the math and got the correct scale in for my WB02.
The spark tables have been updated and I believe it is good now. The MAF Table has been updated to the stock 5.3 table which should match the sensor as it came off an 02-04 5.3 or 6.0.

 

I have the bin setup to tune the MAF today (PE and Open Loop are set to 12.5 and min closed loop temp maxed to 150c) My WB02 scale isn't working. I did the math and figured what each voltage should be but it must be off becuase when I compare what is in TunerPro to what LogWorks is saying I am about 1.5 to 2 higher than I should be. Maybe someone could either help me on the math or share their WB02 table. I have an LC-1 Wide band from Innovate Motorsports.

I also thought I would share the Excel Sheet I made to calculate the changes to the MAF Table. Simplifies the process a little. Just remember to put your flow numbers into the table.

 

For the wideband, keep it simple. In the LC-1 setup, choose 0 volts to correspond to 10:1 AFR. Choose 5 volts to correspond to 20:1 AFR. The conversion then is quite simple as there is a range of 10:1 AFR over a specific # of cells (in this case the step size is .625 AFR/cell). Also make sure that the ground on the D/A output of the LC-1 is tied to a shared ground with the PCM, to ensure that there is no bias voltage that will throw the conversion off.

 

I'm headed out to the truck to figure out this problem with different WB02 readings. I am going to make sure the cab is grounded to the motor and the frame and battery to see if I am loosing a ground somewhere.

Can someone tell me how to change the data rate (Hz) in TP RT V5, I need to force it down to 8. I am getting a boat load of errors when I am logging. I also read something about adding a pause command into the ADX??

 

Tuning the MAF table can be a real pain in the butt. I've spent a lot of time with mine and its finally getting about right. What I've found is the table is very very touchy around idle and the higher up you get the less touchy it is. Like dimented said, you have to give it time to stabilize at a given HZ before you get the actual reading. I've had the most success finding an open stretch of road and starting out with it in 2nd gear (4L80E), very very slowly take off and accelerate. You will want to be in open loop of course and set the open loop table to something like 15:1 across the board except at 100 kpa, it should be set to something even like 13:1 to offer enough fuel to not melt pistons but give you a solid number to compare to. You can do 14.7:1 across the rest of the table but I like 15:1 to conserve a tiny bit more fuel. You will also want to disable Power Enrichment so it doesn't start adding fuel and changing things on you.

As for logging it, I like scanner pro. I took the fuel trim histogram and set it up as the MAF table and it looks to wide band input to put the AFR for each HZ into its corresponding cell. Then I select running average and play it back and it gives me a fairly accurate data of what each cell is running at.

 

my problem is that either the computer has a bad ground or I have a floating ground between my Cig Lighter and the computer. The number in LogWorks is right I'm sure but the number in TP is off. Until I do that I can't make any progress.

I will ask if anyone can point me in the direction to fix my floating idle while I work to get the whole WB02 stuff worked out. I have to be at a dead stop for about 3 or 4 seconds before it comes down to idle not to mention the fact that the truck with drive itself when I have it in gear. I didn't touch the gas coming through town and with it in 3rd gear I was going around 20. I can feel it defuel and then start fueling again. I guess until the MAF is calibrated all bets are off?

 

your using an LC-1, and not the LM-1, right? I tuned my setup with just an LM-1, and with MAF, you dont really need to datalog as the MAF tune is independant of the engines RPMs, MAP, and load. All your doing is really adjusting each cell so that it reflects the right flow.

As for the idle, I still suspect that its running lean. What does the AFR in logworks say at idle in open loop? Also, it could be the tune as well. The $0D MAF just comes with a very generic tune, which is why the truck doesnt quite run right. It wont run well until the PCMs calibration is, well, calibrated. It can and will work well, but we need to get the datalogging issues fixed first.

If you have a way of directly observing the AFR from teh WB controller, you can tune w/o datalogging. I cant even datalog on my vortec PCM. I tuned that just using the LM-1. If you can directly observe the AFR while you drive (you may want to get a helper, or find an empty road for this), I can walk you thru on how to tune the MAF. If your good at it, it only takes about 3-4 chips to get the MAF calibrated. The MAF output is a square law function, so you dont need to know every point exactly to recalibrate teh sensor. You really only need to observe and tune 10-15 operating points along the MAF table from idle, to WOT/high load. You can then just fit a curve to the data you have, and the MAF is calibrated.

Also, are you using the cig. lighter outlet for power and ground for the wideband? That will cause all sorts of grounding problems. You need to run a dedicated ground from the ground of the D/A output on the WB controller to the PCM. You can even just attach a ground wire with an alligator clip to the PCMs case if you dont want anything permanent. There just has to be a direct ground between the PCM and the wideband controller for the output to be correct in tuner pro. Otherwise, the bias voltage and noise on the indirect ground path will cause the output to drift or be incorrect.

Lastly, did you try recalibrating the WB output based on what I said? That is much easier than using the default settings and trying to estimate what the voltage output will be and entering that into the WB output table in tunerpro.

 

Actually, it looks like that feature was done away with. I have used TP5 on my PCM on the test bench, and it worked fine for datalogging, so it could also be an issue with your cable, or your computer. What kind of cable are you using? What type of computer? Does it have a serial port? USB?

 

I am using an LC-1 yes and I did retune both the controller and TP to reflect the changes you mentioned. I ran a ground and power from the PCM and it didn't change the problem. I am using a usb ALDL cable I bought from moates hooked to my laptop running windows 7 (problem was there with XP also). The funny thing is I don't get errors in my stock 93 suburban that is equiped with a 4L60E.

I will hook stuff back up and check my AFRs again.

 

So the main problem now is with the datalogging, correct? There are some differences in how the MAF code executes things. Its more intensive. If TP tries to access the ALDL too much, it can cause overhead issues to the point where the PCM will be terminating prematurely in a transmission to restart the software loop. One thing you could try is to upload the stock $0D definition and simply try the datalogging. If it still does it, then its a hardware fault.

Also, did you remember to re-enable the checksum? The out of the box $0D MAF has it disabled. Check the Mask ID in TP and make sure its set to 0D and not AA. If the checksum is not enabled, it can cause issues as the PCM will continue regardless of whether there is an error or not. Ive had the same issue with my vortec PCM when I forget to enable the checksum. It will do strange things when there are errors in the bin.

 

The mask is set to 0D already. Datalogging is a problem yes, but there are others that I don't think I can address until I ensure the MAF is Tuned. I tried switching out the PCM with another 427 I have laying around and it didn't make a difference in the number of errors. I do have another ALDL cable that is serial that I can rig into the truck and see what it does for errors. I am at work so I will try it on my lunch.

 

Did you ever get a chance to try the other cable? Curious if your still having issues.

 

I will be doing all the wiring and testing of Datalogging and troubleshooting today. I have been swamped lately and haven't had time to think about it. I do have a question about the duct work and air filter setup with a MAF sensor. I took my air filter of the sensor today and took it down the road, it didn't run perfect but there were noticable differences in some areas. The only downfall I have discovered from running the engine with the filter is the obvious and under high load i.e. 5th gear floored and lugging is when I let off it puffs black smoke but not when I am in the throttle. My thinking is that the cone filter I have on it is too restrictive. I have the MAF attached right to the caddy bonnet and then the filter right at the end of it.

 

The filter will have an effect on the mafs calibration. The change in airflow over the sensing elements causes the output to change. At this point, its not calibrated, so you will likely see more of an effect. Also, the rich on decel may be the maf cal, DE, or something else. Until you can tune, its too early to tell.

 

Alright so the WideBand issue is finally cleared up and errors are few and far between on the datastream so finally some good news on the thread. I was rich by about 1-1.7 points on the AFR so I have the math worked and the numbers in the BIN. It was a busy day today at work so I was able to do it during my down time. I will stick the chip in the truck and see how it goes.

Any idea on why my timing is going straight to 41.77 degrees of advance when I start the truck and after about 15 seconds it will instantly come down to 22. Same thing when I am driving down the road under low load situations. The MAX I have in my whole table is 38.68 and it will hit 39 all the time under lower load but coasting always gives me the instant 41.77.

 

The AFR issues are finally gone, the MAF is tuned or so I think...I'll Explain

Cruising with a commanded AFR of 14.7 gives me from 14.5 to 15..Close enough in my book because it will sit on 14.7 every now and then so I figure the movement is normal, correct me if I am wrong.

When I push down on the gas enough to hit PE (12.5) it will sit around 12.8 to 13.5 as much as 14 sometimes. Does this mean I still need to add in more fuel to the upper regions of the Table, I am assuming yes.

I will say it pulls great till about 3600 and it starts to flatten out, I don't think that a .6 error in AFR would cause that, I am thinking it is a timing issue there. I will save my next line of questions until we are good with the fueling.

 

The timing may have to do with how the conversion is handled for the SA. The SA is a signed value, so it may have to do with how its represented in the ADX file. Which ADX are you using?

Edit: Also, have you zero'd your main SA bias out? If thats zero'd (which is OK in itself), but the main SA remained unalterd, the timing will increase by 10 degrees, which would cause the timing to increase. This could also be an issue of other SA compensation being added for the cool temp or IAT SA compensation. If they are a few degrees apiece in those MAP/RPM areas, they can easily force the timing beyond 42 degrees, at which point the PCM will clip the timing to prevent cross-firing in the dist.

 

Datalog the WB and MAF g/sec output. The g/sec values that coorespond to the associated AFRs in each frame will roughly be the values that need to be changed. For example, of the airflow is 150 g/sec and the WB AFR is 13.5 and the commanded is 12.8, then the cell containing 150 grams/sec and cells around it need to be multiplied by 13.5/12.8. The MAF airflow curve is essentially a parabolic function. When you get done, make sure that you smooth the MAF flow curve out to approximate this, using the known points to fit a new curve.

 

What would you recommend doing for the SA vs Coolant/kPa table? Could I just zero it out and just use the timing table itself or would that be counter productive?

 

I usually zero out the CTS and IAT SA compensation until the main SA table is tuned. Then you can set it after the fact to add more SA when cold, less when hot, or whatever is needed.

 

By doing this I am not asking someone to tune, but to look at my bin with as much detail as they can stand and tell me what I am doing wrong here. My timing is running at the limit, past any value in the tables, when at low load or High RPM. The idle is high and the throttle follower is hardly working. I am shooting blindly and I believe I am over my head. My biggest problem is that I have recently found out I am leaving the country and I have about 2 1/2 months to get all my stuff in order. I have to sell this truck sadly and just need to get it out of here. I am going to attach my bin that is setup for tuning the MAF along with a log I just took, the adx and xdl files.

If I am out of line please don't hesitate to tell me, I'm just a little stressed over the recent news.

I can tune the Main open and closed SA Tables and I can get the MAF tuned out, the little details are killing me here and I think preventing me from progressing with the tune.

As always thank you so much for the help already provided and the help to come.

 

No, no problems. I hear you about being pinched for time. Sorry to hear that you have to sell the truck. I assume that your in the millitary?

How does it run? Does it run like it has too much timing? It could be a simple display error in tunerpro, or something worse in the bin. Ill take a look at it.

 

Sorry if I havent convayed some things clearly enough up to this point. Ive been messing around with PCMs for so long that I forget all the details that go into making it work. What might be automatic for me when tuning probably isnt something that you would normally think to do. I'll try to take a close look at things and get the truck running OK for selling it.

 

I figured out why the datalog looks weird. The ALDL xmission addresses never got updated. The timing is probably fine. IIRC, the only thing affected that was major was the timing. I sent an updated copy of the table at one point with the new ADX, but I guess it got lost in the suffle. Heres an updated version of the bin if you want to datalog again and see to be sure its all OK. Ill comb thru the rest and see if I can find anything.

 

Timing is still bust running at a cool 41.77 just about all the time unless I load the motor enough to pull it down and even then 29 degress is all the lower it will go.

I am using the adx and bin you sent but the speed isn't displayed right anymore, I am wondering what the addressing for the speed is so i can tweak that.

 

I found some inadvertant mistakes made in the bin when it was edited during the tuning. The cool temp SA compensation was set at +20 degrees of SA, causing the engine to be overtimed. Conversely, the MAT SA was set to pull 20 degrees of SA at WOT from 3000-4400 RPM or so, cuasing too little timing at WOT, hence the engine rolling over at high RPMs. The throttle follower also was disabled. Additionally, the SA tables look like they may be too conservative. I have some from my old vortec TBI engine that worked well. I removed some timing to tone them down for a truck, enriched the PE AFR, and set the proper open loop AFR. If your not using a cat, you can adjust the open loop AFR as needed, but whats there should work well for most conditions. Give it a try and see how it works.

For reference, be careful when editing tables. If you have any questions, just ask. A small slip of a finger can make a big difference in how the engine runs if a cell gets the wrong value.

 

Heres the ADX file I have. The MPH match what is in the ALDL xmission table. If it still doesnt work, let me know.

 

Also, I thought I sent updated files at some point. Maybe I didnt? Your XDF is ANCIENT! Thats why some of the tables werent working properly. I attached the one your should have.

Anyway, sorry about that. Thought you where working off of the latest files.

DL the new bin, ADX, and XDF, and you should be up to speed.

 

Thank you so much Adam for your HUGE help here. I am working on tuning the MAF now and what a difference in the way the rig runs. I should be able to have this wrapped up and out of the driveway next week if all goes well. Does the throttle follower work better as the maf gets dialed in at idle? How would I increase it if I wanted to.

 

The TF is more or less seperate from the tune. The TF action can be reduced if the fueling or SA are not quite right. However, you can increase it. The first table is the throttle follower gain vs. cool temp, which increases the throttle follower with respect to the throttle position. The ammount of closed throttle TF can be increased by raising the lower limit for throttle follower TPS, which will increase the closed throttle throttle follower.

 

I take it this worked out ok, and you got the truck out the door?

 

We ended up carbing the motor so yup it is out and on it's way. I saved the shtuff for a project down the road.