MAP ECU 2 Tuning Issue - Doesn't Seem to Hold Tune

[theprodigy79]

My mechanic has been working on my tune for several weeks now (on and off) and finally seems to have a configuration that runs well and maintains good A/F ratios from idle through heavy throttle... The problem is, he has to re-load the file every time he starts the car or it seems to lose the tune, and he can't seem to pull the tune from the ECU (which worries me, since I don't want to lose or change anything if I use my laptop instead of his)...

Does anyone have experience with this issue?

I have done research on Map ECU's website - we have the OEM O2 sensor permanently disconnected / pulled the EFI fuse. I have an AEM UEGO wideband. He's been over the wiring many times and hasn't found any issues.

I'll detail my setup if necessary, however not sure if it's helpful considering he can get it tuned sufficiently, but it just won't seem to keep the tune.

Let me know if more information is necessary.

Thanks in advance,

James

 

[Suprapowaz!(2)]

I would plug the stock O2 sensor back in and tune to satisfy Vf. You may be having an issue with the MAPECU2 unit itself. Contact them to see if they can look at it. Do you have an afm you can put back on just to cruise around in case you do have to send it off?

 

[19supra90]

From what I've read you always want to satisfy Vf like suprapowaz said. Satisfy Vf in closed loop. Then tune in open loop. If you don't satisfy your Vf, the ECU will throw out your tune. I've also read that there are issues tuning our cars with MAPECU, for whatever reason I'm not sure, it's just what I've read.

 

[theprodigy79]

We unplugged the stock O2 sensor because that's what a thread on the MAP ECU site (posted by MAP_ECU Man) said to do in order to prevent the ECU from overriding / 'correcting' the A/F ratios, but I'll look into that further. I do still have my AFM laying around, but the car's been parked for 3+ years anyways so it's not any urgent matter (and it runs lumpy without a tune as well - I have 272 degree cams, though the ECU did seem to adjust for them over time and ran more smoothly before I got the piggyback).

I haven't really heard of any recent tuning issues for the 7M using the MAP ECU, aside from it's a fairly complex process due to how detailed the tables are. In the beginning I heard of several issues, but they were mostly due to incomplete data on how to use / wire it.

 

[Trent]

I had the very first MK3 with the original MAP-ECU when it came out and while I was working for PHR at the time. The tuning is definitely tricky on these cars. Definitely more so than with other piggybacks that I've used on 7M's prior and since, but once it is setup and working correctly, its an excellent piggyback to use.

Sure sounds to me like it is a MAP-ECU issue and a memory problem within it. Just my opinion.

 

[theprodigy79]

That's what I'm wondering... We actually had a syncing issue with this unit initially, so we sent it back to the MAP ECU for inspection. They performed some sort of 'warranty service' on it for free (I believe it was probably something simple like a firmware flash or something) and sent it back. From there we've had no issues with getting it bonded with the computer and tuning, however I was thinking it may be a memory issue as well...

I just wanted to cover my bases before going back to the company, and make sure it's not something stupid (or unique / unobvious) that we're missing.