1996 855 T5 - eBay ECU?

Sommerfeldt · Post by **Sommerfeldt** » 27 Jul 2016, 02:17

I've been looking to convert to M4.4 for a while, but the A/C fix has had me a little worried. I came across an ECU on eBay yesterday, where the seller reports that the software fix for the A/C has been done, and that the ECU can be dropped right in. He also says (when I sent a couple of questions) that this thing will deliver almost 300 hp when it's paired with white or blue injectors...

So, question - he wants 330 USD for it (which will clock up a little more with import charges and shipping) - what do you guys think? Safe, unsafe, worth it, not worth it?

- S

Post by **tryingbe** » 27 Jul 2016, 06:50

Do you have wideband oxygen sensor on your car?

There is a software modification that can be done to the M4.4 calibration for a while.

I'd never buy an off the shelf tune.

Sommerfeldt · Post by **Sommerfeldt** » 27 Jul 2016, 06:58

Nope... no wideband. I see what you mean - but I'm no tuner. I can turn a wrench, but fiddling with software isn't my strong side. I'm wary of the HP claims he made - if he had said it was a standard 850R setup, but with the M4.4 conversion and AC fix, I'd be much more comfortable.

What I'd like is an M4.4 conversion with the AC fix, but I haven't been able to figure out which ECUs have M4.4 from the serial/part numbers on them, so when this one popped up ready to go, it's tempting.

- S

Sommerfeldt · Post by **Sommerfeldt** » 27 Jul 2016, 07:14

So if someone wants to make me an M4.4 conversion with a stock 850R setup and the AC fix, send me a PM - I'll pay through the nose.

- S

Post by **erikv11** » 27 Jul 2016, 07:59

There is so little difference between a stock R ECU and a stock T5 ECU in terms of HP, IMHO. I would be wary of someone who says the ECU will perform differently with different injectors - it should be tuned for a certain injector size, it's unwise to swap injectors around without altering the tune accordingly (although admittedly, those swaps can be OK).

In my 95 T5-R I run M4.4, on just the stock T5 tune. It's great.

Post by **abscate** » 27 Jul 2016, 08:02

Sommerfeldt wrote:Nope... no wideband. I see what you mean - but I'm no tuner. I can turn a wrench, but fiddling with software isn't my strong side. I'm wary of the HP claims he made - if he had said it was a standard 850R setup, but with the M4.4 conversion and AC fix, I'd be much more comfortable.

What I'd like is an M4.4 conversion with the AC fix, but I haven't been able to figure out which ECUs have M4.4 from the serial/part numbers on them, so when this one popped up ready to go, it's tempting.

- S

Have you seen if Henry (double bug) can help you with this ??

Post by **tryingbe** » 27 Jul 2016, 09:58

Sommerfeldt wrote:Nope... no wideband. I see what you mean - but I'm no tuner. I can turn a wrench, but fiddling with software isn't my strong side. I'm wary of the HP claims he made - if he had said it was a standard 850R setup, but with the M4.4 conversion and AC fix, I'd be much more comfortable.

What I'd like is an M4.4 conversion with the AC fix, but I haven't been able to figure out which ECUs have M4.4 from the serial/part numbers on them, so when this one popped up ready to go, it's tempting.

- S

First, what car and options do you have? What are looking to get out of it?

No wideband o2 sensor should automatic means no tuning of any kind for you. It's a big risk running a "tuned" non factory ECU.

In US, all 98 turbo ECU are M4.4, they can NOT be use on a M4.3 car without either software or hardware modification, as it will make the a/c non-functional as well as check engine lights would be on for the missing M4.4 sensors/solenoids that are not on a M4.3 car.

I have a 94 850 Turbo auto and I was using the 96 auto R calibration burn into the chip then inserted to a 95 turbo ECU, pretty happy with it since this is my daily driver, reliability is top priority, not top power. A/F is perfect, no issue with it.

Then I put in a manual transmission last December. After the transmission swap, I tried an auto factory 95 T5-R m4.3 ECU. It runs fine for the first 15 minutes or so, then check engine light comes on as the automatic transmission ECU is no longer there, and boost seemed to be reduced.

Then I put back the 96 auto R calibration into the m4.3 ECU and then into the same car, manual swapped car. http://www.chiptuners.org/forums/viewtopic.php?t=100 Check engine light suppose to come on, but it never does. This calibration also works on an auto car, since this is what I had before swapping the auto transmission for manual. The ECU is definitely for an auto, as the RPM drop as soon as you step on the clutch, but I actually prefer it this way instead of the RPM hovering for half a second before dropping. Boost to around 10psi.

Then, hearing all the hypes regarding to the M4.4 ECU, better gas mileage, better ECU control, more ram, more processing power, etc. I bought a 98 m4.4 ECU, using this "608_rev5b.bin (original unmodified)" from http://m44.wikia.com/wiki/Factory_Binaries , I put the calibration with the blue injectors into my car thinking this will be great. NOPE, big disappointment. A/F is way lean at 0psi first few time you start and run the car I'm talking about 16-18 a/f lean, the kind of lean will make your car dead slow at take off. It eventually worked itself out, but every time you disconnect the battery or ECU, the issue comes back. Above 5psi it runs too lean at 13-14 a/f, the kind of lean that would damage the engine if you stay on it, this never resolved itself until I change the fuel map. Gas mileage scale is way off, showing average 30.2mpg while actual miles per gallon calibration net a 25.3mpg and I have to change the injection scaling. Boost to around 15psi, which I thought is not suppose to be this high. I am not happy with this supposedly stock 98 T5 tune at all since I have to do all these work to just get it to the baseline.

Honestly, I like the 96 R ECU the most, put it in and forget it.

Sommerfeldt · Post by **Sommerfeldt** » 27 Jul 2016, 10:52

Huh...that sounds very weird to me, tryingbe. Honestly, I had a hard time following that narrative, but it sounds to me like you have made far more invasive changes to your car than me. For now, my car is all stock, except a few tweaks such as sports filter, etc. Nothing major. Nice, clean orange injectors and all.

My goal? For now to run a stock T5 M4.4 with the AC fix, and teach myself tuning as I go along, and be able to use the full spectrum of OBDII functions. For later? White or blue injectors, my own tune when I've learned enough, and tipping out at maybe 280-290 hp. Far down the road.

Btw, you say the lean condition fixed itself - the correction spectrum is only about 20% isn't it? So could it really have been dangerously lean?

In any case, it's always valuable to get the negative experiences as well - Erik has iffered to make me an M4.4 ECU, so I'll try it out in any case. If it turns out to not be what the "hype" has made it out to be, I'll still have my old one to pop back in.

- S

Post by **tryingbe** » 27 Jul 2016, 11:10

Every car is setup differently and needs different things. My advise is to buy and install the wideband o2 sensor first before you install any tune.

Sommerfeldt · Post by **Sommerfeldt** » 27 Jul 2016, 11:43

tryingbe wrote:Every car is setup differently and needs different things. My advise is to buy and install the wideband o2 sensor first before you install any tune.

That's probably sound advice. But would you say I should get one now, before popping the M4.4 with the stock T5 tune in, or can it wait until I'm gonna fiddle with it? Also, any recommendations as to make and model?

- S