7427 MAF 700R4 BIN Help

[halljam70]

Finished the 7747 to 7427 swap about a month ago (recommend) followed by installing a three wire vortec MAF and separate IAT sensor (HIGHLY RECOMMEND the 7427 / MAF setup for TBIs!!!!) Truck runs so much better than before but I've got two issues that I haven't been able to solve since swapping to the MAF bins.

1. 700R4 TCC: Since swapping to the MAF, the TCC in my 700R4 has not worked. Originally the $0D_MAF.xdf file I was using didn't have any TCC scalers or flags present. I copied and pasted some from another $0D non MAF mask, but it still hasn't worked. If I throw my old speed density chip back in the TCC works fine. In the 7427 pin out swaps I've read, I saw some debate on which pin to put the TCC on. I'll go back and look at my notes to see where it is now, but I know I moved it from the original pin I first had it on. But, again, with the speed density chip in, TCC locks up fine.

2. EGR: All the MAF masks I find already have the fan hack in them. I need the EGR to function in order to pass emissions. Disclaimer, I have not had the truck tested again since moving to the MAF setup. Tested it two weeks ago before the MAF swap and it failed due to HCs being above the state limit. Truck was running BLMs of 118 - 120 @ 2500 (2 minutes, part of Nevada's testing procedures) and idle BLMs were around 123. I plan on testing it again today once I put new plugs and plug wires in the truck. Truck does all in town driving and the AC plugs (R43TS) might be too cold.

Last question is for educational purposes. I see the differences between xdf files others have built in the forums. How do you edit/build them? I was using right click copy the copy xdf parameter to clip board, then open the xdf file I was using and pasted it in. Which hasn't worked.

Big thanks to Eagle Mark, Fast355, 93V8S10 and Dimented24x7 for all their TBI posts.

[halljam70]

Update for anyone that can use this. Truck past without having a working EGR. I modified the ADX file to MAF flow frequency table matched my three wire Vortec MAF sensor. I'll post the files shortly. Still working the TCC issue, but once I have that fixed I'll post the bin.

86 Chevy Silverado
PO rebuilt 305
416 heads
204 214 duration 112 LS flat tappet cam
stock TBI intake
stock over the plug exhaust manifolds (replacing them is the next project), factory y-pipe to 2.5" converter, 2.5 single in dual out flowmaster muffler
1997 three wire vortec MAF. Cadillac bonnet (2nd one, first one had an internal baffle), Spectra cone air filter attached directly to MAF
AC 43 plugs, Taylor pro wires

I will convert any future old car project to the 7427 computer, TBI, MAF set up. Drive-ability over a carb is night and day.

[notime2d8]

Hey, i am following this, as i haven't gotten my setup running right. I'm working on adding a VSS now. Glad to hear you got yours going!!

[halljam70]

what are you working on? I used a signal generator on My LT1 swapped Nova, but if I had to do it over again, I would use a 700R4 or 4L60E and converted the dash to an electronic speedometer. I converted my Silverado to a later model (91) Suburban dash due to the PO swapping in a 700R4 that didn't have the speedometer gear housing for the stock cable driven speedometer. Figured I had taken from this web site for the last couple of years, the least I could do is try to contribute.

[JeepsAndGuns]

I have been curious about the MAF mod. Seems all the people that I have seen online that have done the mod really like it.
I wonder if it can be done in conjunction with the MPFI mod (which I have) and if it would be a worthwhile venture or more possible tuning and diagnostic issues in the future.

[halljam70]

I've read threads that cover the 7427 w/ MPFI swap, but I haven't seen it used with a MAF. I'm trying to learn how to write in HEX so I can get the lockup on my 700R4 to work. The MAF / 7427 is lights out better than the 7747 I installed first. Granted, I wasn't that great with tuning, and I'm not using a wide band which may have caused some of the issues I had early on. The MAF setup allowed me to close the BLM range down to a couple of numbers either side of 128, where as in speed density mode, the truck would tend to run in the 112 - 115 range at idle, which is the reason she failed the first smog attempt.

[JeepsAndGuns]

Question. Did you ever have a working tcc once you swapped to the 7427? Did you swap from the 7747 to the 7427 and tune it as regular tbi and have a working tcc, but then swap to the maf and then loose tcc?

[halljam70]

That's exactly what happened. The 7427 MAF XDF files I'm using don't have the TCC options in them like the 7427 non MAF masks I've found. I've started dropping scalers into the attached mask from one of the non MAF masks I've found. I haven't moved enough lines of code over yet to get it to work. I've thought about going back the other way and dropping the MAF items into one of the non-MAF masks. The one I've started messing with is attached.

This morning I plan on dropping the non-MAF chip I kept as a backup to see if the TCC will work. The one item I have done since swapping to the MAF setup is relocate the TCC to a different PIN (found it in a discussion thread on 3rdGen). If the TCC doesn't engauge this morning, I'll move the pin back and try moving more code over into my MAF bin.

[halljam70]

I put a BJYL bin in the computer tonight. With the TCC wired to pin E11, it worked perfectly. Nothing when wired to E10. I plan on copying all of the TCC code over to my MAF bin and see if it will work now that I know the TCC works.

[Fast355]

I put a BJYL bin in the computer tonight. With the TCC wired to pin E11, it worked perfectly. Nothing when wired to E10. I plan on copying all of the TCC code over to my MAF bin and see if it will work now that I know the TCC works.

Post up your current MAF bin. I will try to fix the TCC for you. Honestly been too many years since I have messed with it to remember if the TCC was E10 or E11. But when you are running the 700R4 side of the TCC code, your TCC will be on the PWM TCC output. You have to disable the Electronic transmission switch and turn the TCC switch on to run the 700r4 logic.

[halljam70]

Thanks for the offer but you've fixed it already. I copied your 700R4 code into a MAF xdf file I'm using. Tested it out this morning and it worked like a champ. Pin E11. I'll post the bin, and xdf files when I get back to the house. When I search for the 7427 stuff I never look to see how old some of these threads are. One question I do have is if you used the factory TBI collar under the Cadillac bonnet? I've ran my both ways and have noticed a significant impact on my BLMs. Currently weighing moving from the factory TBI intake to a performer intake and adapter. Haven't found anything that has dyno numbers other than the old performer vs stock cast iron four barrel intakes. I should just drop a 5.3 in this and be done with it but the 305 runs too good to justify kicking it to a corner of the garage.
Have a Happy New Year.

[halljam70]

Here is the modified XDF (for 700R4 TCC control), ADX (correct vortec three wire MAF tables) and BIN. Hope others can use these. I'm not taking credit for these, I only modified XDF and ADX files others have posted. The file names were so I could keep them straight on the computer.

I also uploaded a log from yesterday. You'll notice how it freezes or locks-up while driving. I haven't figured that problem out yet.

[Fast355]

Thanks for the offer but you've fixed it already. I copied your 700R4 code into a MAF xdf file I'm using. Tested it out this morning and it worked like a champ. Pin E11. I'll post the bin, and xdf files when I get back to the house. When I search for the 7427 stuff I never look to see how old some of these threads are. One question I do have is if you used the factory TBI collar under the Cadillac bonnet? I've ran my both ways and have noticed a significant impact on my BLMs. Currently weighing moving from the factory TBI intake to a performer intake and adapter. Haven't found anything that has dyno numbers other than the old performer vs stock cast iron four barrel intakes. I should just drop a 5.3 in this and be done with it but the 305 runs too good to justify kicking it to a corner of the garage.
Have a Happy New Year.

My LE9 305 with a 204/214 cam and headers ran very well with a performer RPM intake and 454 TBI on an adapter in my 1983 G20 van. Intake ran well with a carb on it as well, but the TBI was more refined.

[halljam70]

I've got a performer EGR intake I was thinking of putting on the truck (replace the factory TBI intake), and the reason is sitting on top of the intake. Before that, I need to rethink the exhaust system. Current over the plug manifolds have AIR blocked. Makes it a pain when I SMOG test. They flow into a factory y-pipe, 2.5" outlet, 2.5" cat to a flowmaster muffler. I wanted to do headers dual cats, true duals, but that won't be legal here in Nevada (talked it over with Ref station. Can't stand the visual requirement, if it is under the limit, its under the limit, shouldn't matter what it looks like under the hood). Now I'm thinking of going with stock 1990 suburban under the plug manifolds. Factory y-pipe (3" outlet), back to an aftermarket 3" cat then a single in/dual out muffler. Not sure it will help performance but it would eliminate my two biggest issues left. 1, removes all evidence of the AIR system so the truck will pass as a later model motor swap. 2, eliminate burned plug wires.

[Fast355]

I've got a performer EGR intake I was thinking of putting on the truck (replace the factory TBI intake), and the reason is sitting on top of the intake. Before that, I need to rethink the exhaust system. Current over the plug manifolds have AIR blocked. Makes it a pain when I SMOG test. They flow into a factory y-pipe, 2.5" outlet, 2.5" cat to a flowmaster muffler. I wanted to do headers dual cats, true duals, but that won't be legal here in Nevada (talked it over with Ref station. Can't stand the visual requirement, if it is under the limit, its under the limit, shouldn't matter what it looks like under the hood). Now I'm thinking of going with stock 1990 suburban under the plug manifolds. Factory y-pipe (3" outlet), back to an aftermarket 3" cat then a single in/dual out muffler. Not sure it will help performance but it would eliminate my two biggest issues left. 1, removes all evidence of the AIR system so the truck will pass as a later model motor swap. 2, eliminate burned plug wires.

I did the same thing with my old G20 before I put headers on it. The manifolds were the later TBI G20 manifolds with 2.25" outlets and the Y-pipe went into a single 3" high flow cat. The stock setup was under the plugs but had 2" pipes into a 2.5" pellet cat. Power was night and day difference.