OBD1 motronic tuning thread?

[B4S]

Got it all together and started the tuning. Due to my stupid idea of running the counterflow head, I've had to delete the ISV due to it allowing too much air in at idle. It would need HUGE fuel map changes to compensate, but when revved, it would be too rich and stall out. Until I figure out the ISV mapping, I've cracked the TB open a bit more and plugged the ISV port. I'm half tempted to swap back to the crossflow head, but that would mean a few more weeks of work (car time is not really available much ).

[B4S]

Well, I've got egg on my face right now. It was pointed out to me that my ISV issues may be caused by the fact the ISV is sucking unmetered air, instead of post-MAF stuff. Guess I have no excuse for that one . I'll be fixing that tonight and starting over. I bet this solves a lot of my problems...

[B4S]

Awesomeness .

Now that the ISV is working the CORRECT way (I'll never make that mistake again, lol), everything is completely fine. I did a bit of tuning tonight and got the code scaled for my 358cc injectors. Idling perfectly at 14:1, and starts at the wave of an oily rag . I've started making an XDF for the ABA that's only got the needed stuff in it, and it's what I used tonight. I re-addressed a few things, to make tuning simpler, and it works great!

I'll be uploading the 'tuner' XDf and modded stock chip file tonight and will post the link for anyone who wants to use them. This XDF will only work with the modded chip file, but the regular tuning files are also available.

The files:
http://www.ecuconnections.com/forum/...=813&start=200

[AJmustDIE]

Wishing my car was OBD1 nao ,

[B4S]

Narrowing down the warmup enrichment map possibilities, just have to let the car cool back down and try again. It was idling at 9:1, but I think the map I was using brought it up to 13:1...but by the time I tried to confirm, it was warmed up, lol.

[B4S]

Found them . Got my warmup to 13:1, but it's still a bit rich after cranking. Not a huge deal, tracking that next. I'll be redoing my files and hosting them on my webspace and tunerpro.net today .

[B4S]

Finished the abridged version of the XDF, which only has the useful stuff in it. I'm in the process of getting it uploaded to Tunerpro.net . All current files are uploaded to the thread on ecuconnections too.

[mozcar78]

ISV huh? LOL. Glad you got it sorted out.

Thanks for posting that XDF.

[B4S]

Yeah, feel kinda stupid about that ISV thing. Not used to MAF-based efi I guess, lol.

[B4S]

Ok, surprising bit of news for the day: VW used M2.9 overseas in other 4cyl cars. Never would have figured that, since I figured all their Mk3s were digi-3 based, like the 2E in the Mk3 GTI, and the ABF. Someone on the ECUconnections forum posted a 1600cc version, file # the same as our North American ones, with the "AQ" suffix. All the maps line up perfectly in the XDF too! I'm going to examine it further tonight, maybe there's something else in there that might point to an injector constant (if it exists), since the 1600cc engine has to use smaller injectors than stock ABA, I hope .

['dubber]

People sweat the full euro-spec ABF setups for good reason!

[B4S]

The ABF stuff is digi-3, not M2.9. That's why I was surprised to see the smaller 8v engines using M2.9. There isn't a huge difference between files, in the mapping areas, so there has to be a spot that tells the ECU what injectors are being used. The problem is that the hard code/processor area is completely different, and we still don't know how the stock ABA ecu stores the stock injector data. No clue what to look for, since the majority of the code in that area is different .

[B4S]

Haven't started the car in weeks, so I went out, turned the key to acc so the wideband could warm up...reached through the window...VROOM! Idled happily at 9:1...then 10:1...then 12:1...and finally 14 . All the money I wasted on standalone EFI for my mild-power setups could have bought me an 89 Porsche 911 turbo, lol.

['dubber]

Ah I see, I just know that abf euro setup is better...

[B4S]

It's better than the CIS-Motronic we got on our 16vs, that's for sure. No idea how it compares to M2.9.

I can finally confirm that DIY boost tuning works great. I went for a dangerous test drive (87 octane, 10:1 compression, hot plugs, and 15psi by accident), and had no troubles at all. It misses a bit, but I'm not surprised really. Junkyard ignition components and hot plugs are a recipe for that.

When I get back I'll probably stack some gaskets, just to be safe. My wallet can't afford a summer of 98 octane race gas. I'd love to give E85 a try, but the lone corngas pump in my area is an hour away .

['dubber]

So you are basically still utilizing all of the available oem fuel tables out of boost? How is the the "around town" drivability and what did you have to mess with to maintain it if anything?

[B4S]

Pretty much, just scaled for the larger injectors. I brought the TPS/Base fuel table down quite a bit, and the idle fuel as well, but the part-throttle fuel table is almost at stock levels. I brought it down slightly, but only about 15%. I haven't really tuned for boost yet, so I left the WOT table at stock levels, which seem to work well with the larger injectors. A stock ABA only uses about 2/3 of the available mapping space on the load tables, so there's actually room for boost .

I can't comment too much on around town driveability, since today is the first time I've actually road tested it, but it was flawless . No stumbles at all, except for the ignition miss.

[TIGninja]

I have not looked at your XDF yet but I know you done good Everyone needs to thank this guy. We have a few VRs coming up with large turbos and I will be reworking the XDF to use. I will post the xdf on tunerpro when I am done because there is interest in this.

[B4S]

Damn, thanks dude! Never would have considered trying this if it weren't for your old threads on HCVW ways back, so it's high praise .

I've been playing with a little java-based file that someone posted on ecuconnections that takes any 8-bit Motronic file and converts it to an XDF, including all the axis values. I've tried out the AE 4cyl file, and the EA VR, and it works perfectly. It creates completely raw files though, no descriptor values or anything like that. Populates all the axis' though, which takes a lot of the work out. Gotta run it from the command shell, so it's fiddly, but it does a good job .

I'll be home in a few days, can't wait to get back to work on the tuning!

[B4S]

All the needed files have been re-hosted on my webspace. Found my login again .

No need to register, just click and download.
http://www3.sympatico.ca/tchaad/OBD1...0DIY%20Tuning/

[B4S]

100km drive of great success! I had a few tiny hiccups, but none related to the tuning. My 20 year old starter (yeah, why didn't I change that?) doesn't like getting hot so I needed a boost after pulling over to do a bit of tuning, and there was a tiny stumble that might be related to my TB adapter. Outside of those two things, the car fired up and drove like a champ! It even takes it's boost great, except for the massive clutch slip. I have a six-puck sprung hub ACT clutch ready to go, but need to find time to do it.

All the tuning I did was with the above XDF/bin combo, and it works great, so if anyone is still reading...spread the word .

[mk2golf14s]

good to hear that everything is going good.

[B4S]

I've been driving the car a LOT lately, trying to sort out the miss/surge. Figured it out tonight, so I'll be able to get the chip dialed in soon. I have a clutch to swap in, and then I'll be at WOT non-stop for a few days...on a dyno, of course .

So far though, everything is great! Before the clutch starts to slip, the fueling is spot on.

[B4S]

After a long struggle with a demon misfire, it's gone. I swapped to a G60 coil, and relocated the ICM out of the engine bay. I just got back from a drive where I treated the car like a rental...and all is well . Now I can finally get to the fine tuning.

['dubber]

Nice man, how user-friendly is the mapping program in terms of identifying and adjusting for problem areas with afr and timing (once you know about all of the maps)? Does it save afr and fuel/timing info and overlay it or something so you can go through it and sort of figure out where you need to make changes based on what it might show you or do you have to do all of that on the fly?

[chinarockfish]

I can't remember if it was in this thread, or the one over at ecuconnections, but somewhere there was some talk of re-working the maps to switch from a MAF to a MAP. Has there been any work done on this? Could data logging both a MAF and a MAP sensor's voltage outputs along with a vag-com log of the MAF be enough to make up a conversion factor to replace the MAF map?

[B4S]

Nice man, how user-friendly is the mapping program in terms of identifying and adjusting for problem areas with afr and timing (once you know about all of the maps)? Does it save afr and fuel/timing info and overlay it or something so you can go through it and sort of figure out where you need to make changes based on what it might show you or do you have to do all of that on the fly?

Unfortunately you have to do it all on the fly. VAG-COM can log everything but O2/wideband data, so you can at least see timing, knock, CLT, IAT, TPS, etc. I'm trying to figure out a way to get the stock ECU to log a 5v signal, but it's not really my area of knowledge, so it's slow going . At least with VAG-COM you can log exactly where you are in any of the maps, which is a definite plus .

As far as user-friendly, it's as simple as any other standalone tuning software. Everything is laid out in an easy to use format, and changes can be made in real time while driving. The software traces the map you're using, so you can see exactly where you are while tuning.

[B4S]

I can't remember if it was in this thread, or the one over at ecuconnections, but somewhere there was some talk of re-working the maps to switch from a MAF to a MAP. Has there been any work done on this? Could data logging both a MAF and a MAP sensor's voltage outputs along with a vag-com log of the MAF be enough to make up a conversion factor to replace the MAF map?

I was thinking about giving it a try, but I haven't decided on the best way to go about it. The software in the chip will need to be re-written a bit, so I'm taking my time and trying to figure out if it would be worth it to write an xdf/bin for a MAP conversion. I still have no idea if it would even work, lol.

[B4S]

Did a bit of testing with a MAP conversion last night. I got it to idle and rev, but it goes super lean when de-clutching and moving. I'm using 358cc injectors, but the values in the fuel tables (both TPS and Load tables!) are cranked up to nearly 200 just to idle! There's a lot going on in the code that would have to be changed I think, in order to get this to work...and I'm not a disassembler . Some other smart guy is going to have to take that and run with it if they want to convert, cause it's just not in the scope of my abilities to do so. I am going to try blow-through MAF though, that's next .

[B4S]

Found the MAF transfer table, I believe. I've known of it's location for a while, but wasn't sure if it actually was what I thought it was. It's a very large 2D table, that doesn't exist in the master map listing. It has a huge impact on fueling when altered. The VR bin file has a similar table, with a different curve in it, so I think it really is the MAF table. I wonder what happens if you swap to the 3" MAF on a 2.0 and put that curve in place of the stocker. Also, I wonder if tweaking this could help with a MAP conversion?

[TIGninja]

Found the MAF transfer table, I believe. I've known of it's location for a while, but wasn't sure if it actually was what I thought it was. It's a very large 2D table, that doesn't exist in the master map listing. It has a huge impact on fueling when altered. The VR bin file has a similar table, with a different curve in it, so I think it really is the MAF table. I wonder what happens if you swap to the 3" MAF on a 2.0 and put that curve in place of the stocker. Also, I wonder if tweaking this could help with a MAP conversion?

Now go look in the code for the location of that transfer. LMK what you find.

[B4S]

Re-downloading now. Old laptop died

I have the three main OBD1 ABA bin files, a copy of the generic XDF (in regular and compressed format), and a quickie document on how to work the xdf all up on my webspace. Here's the link:

http://www3.sympatico.ca/tchaad/OBD1...0DIY%20Tuning/

If anyone downloads it, could I get some constructive criticism please?