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Phil's 98 A4 AHA 2.8QM

Posted: Thu Dec 24, 2009 12:13 pm
by Sodaguard
I have yet to find another MS'd Audi 2.8, so I though I would share it with the community.

Vehicle: 98 Audi A4 Quattro
Engine: 2.8 AHA 30v V6
MegaSquirt: 3.57SMD MS1 029y4 code
MegaTune: MegaTune 2.25p3/Tuner Studio(Trying to get in TS, but I know Megatune far better)
Ignition: Wasted spark DIS, stock coils with the internal circuitry bypassed. BIP373 coildrivers in a separate project case(super easy with the 3.57SMD's DB15 output)
Fuel: Stock injectors
Other: No TPS used for MS(Audi TPS work backwards, a no-go for MS), dedicated GM coolant and IAT sensors for MS. Idle controlled by the stock ECU(surges for some reason on startup).

Description: Quite a pain to Megasquirt. Being the first(that I am aware of) to MS one of these 2.8 A4's I had no diagrams or instructions. I had to probe every wire I thought I would need(narrowed it down by color and Phil logic). This is a piggyback setup(OEM ECU controls too much stuff to ditch it), so I had to leave the factory ECU all of it's inputs, but with the help from DIYAutotune's website I was able to do some sensor "sharing". The two big things that made this install difficult were, the injector wiring and that I had forgotten "Stim For Wheel" turned on(giving me erratic RPM until I turned it off). As far as the injector wiring goes, pretty simple huh? I thought so too. For some reason I had 12v on the positive wires when I checked then to ground, but I still got no fuel... Very perplexed. Well after about a month I checked the ground wires against ground and got 12v, I traced the wires but never did figure it out. So I cut all the injector wires and ran new ones(the Phil way). It took me a little while to get it started, but now it runs pretty strong. As much power as stock if not more, but it does Stumble slightly(no TPS). I'm sure most of you are probably wondering why I don't just install a TPS, no room. Even to pull the intake elbow you have to remove the intake manifold. I tried leaving everything as stock as possible for now, but I do have mods planned.

Eventually I would like to remove my cats, remove my mufflers(enjoy the noise). Then after I get bored with that I would like to turbocharge it, but with the lack of room under the hood it would have to be a rear mount setup. I will try to post pics soon, if any of you have any questions PM me and I'll get back to you. I would post an MSQ but I have a lot of tuning to do first.

Re: Phil's 98 A4 AHA 2.8QM

Posted: Fri Jan 01, 2010 7:58 am
by radics1

the MS2 extra code works perfect with the backward audi TPS.

I modified the MS1 code too,wich works now perfect with the stock tps.You can also change the TPS wires,if the stock ecu is disconnected.

If you like,i can send you the s19 file with the backward tps,code 29y4.

Re: Phil's 98 A4 AHA 2.8QM

Posted: Fri Jan 01, 2010 8:03 am
by Sodaguard
I would love that, thank you! But I did try switching the wires but then I got no TPS signal. The factory computer still uses the TPS so I have to do some sharing, so that s19 file would help a lot.

Re: Phil's 98 A4 AHA 2.8QM

Posted: Sun Jun 06, 2010 7:54 am
by kubeq_sq
hello, do You know what kind of transistors are built into this coils?? how do You can manage this ignition module?? with 5v or groundswitching?? i want to ude that ignition module in my project :)

Re: Phil's 98 A4 AHA 2.8QM

Posted: Sun Nov 20, 2011 7:16 pm
by audi rs4
Hi Phil i really need your help i have an audi a4 aha v6 single turbo,i am using the ms3x.And i would like to know if u can help me with a start up program thank u.

Re: Phil's 98 A4 AHA 2.8QM

Posted: Fri Mar 30, 2012 11:37 am
by tehehodi
How's this project going? I'm looking to get my car running on MS stock and fine tuning that before I go single turbo.

Re: Phil's 98 A4 AHA 2.8QM

Posted: Sun Jun 02, 2013 6:03 am
by Sodaguard
Hello, long time since I've been on here. I sold the car a couple years ago, but I still remember a few things. I modified the stock coils by disconnecting the stock igniter/coil drivers that are internal to the coilpack. I believe I used ground switching to control the coils,the same as Audi used. I used three BIP373's to run the coils and I wired it up the way you wire up any coil. My newest project is a 95 Impala SS, I just finished putting a rear mount turbo setup on it. I plan on megasquirting it soon, but I don't know if I will stay with the turbo LT1 or if ill swap out to a big block. Let me know if I can help with any of your Audi/VW megasquirting projects.



Re: Phil's 98 A4 AHA 2.8QM

Posted: Sun Jun 02, 2013 6:09 am
by Sodaguard
Just a little bit of info for anyone trying to get a car running for the first time, I have never used someone else's MSQ file with any luck. All my MS'd cars have been tuned from scratch. Be patient, use logic, keep your timing conservative and only focus on fuel until its running. Start with less fuel and increase as you go. It is very easy to flood an engine, so be careful. Required fuel is the magic number, but you will also have to tune priming pulses and How MS looks at temperature in order to get it to fire up.