A/T and Cams

[Eniygma]

I recently discovered after installing a high performance racing engine in a A/T Laser, that the 264/272 cams made the car run absolutely horrible.....Back fire through the intake, no idle, etc..Well, after pondering on this for a while I realized that the A/T ECU and the M/T ECU are quite different. So I got a M/T ECU and plugged it in. WALA, fixed! After starting the car and letting it idle for about 15 minutes it cleared up and now runs perfectly....no problems at all (except for my ISC). Anyway, just a quick note to all those looking to upgrade cams.

E

 

[Billios996]

Do you not have any kind of fuel control or modified ecu installed to run your race engine?
Bill

 

[RuBiCaNT5X]

AFAIK, the MT and AT ECU's are the exact same. The difference is that the TCU is what controls the AT. Your AT ECU might have had leaking caps which is why it ran like garbage... I am not certain, but that seems like the logical conclusion to me...

 

[Eniygma]

No management

Do you not have any kind of fuel control or modified ecu installed to run your race engine?
Bill

 

[Eniygma]

AFAIK, the MT and AT ECU's are the exact same. The difference is that the TCU is what controls the AT. Your AT ECU might have had leaking caps which is why it ran like garbage... I am not certain, but that seems like the logical conclusion to me...

That would explain it.

 

[98TalonTSi]

AFAIK, the MT and AT ECU's are the exact same. The difference is that the TCU is what controls the AT. Your AT ECU might have had leaking caps which is why it ran like garbage... I am not certain, but that seems like the logical conclusion to me...

Matt, not to blow up your spot but... (you know I love you)... the 1G ECUs are different for AT and MT. There was a different turbo, injectors, etc. I think you thought he had a 2G.

Eniygma, I guess I could see an ECU swap to clear it up somewhat, but cams dump fuel at idle, so with cams, stock injectors, and a stock ECU on the 1G, I would think it would run like any car with cams, lumpy (but not as extreme as you described. When you put in a MT ECU which is setup for larger injectors and your cams dumping fuel, I guess it balanced it out, since you would run a little lean at idle without cams. Glad it cleared it up, but it doesn't that's odd you put in cams with your stock injectors. Also how are you monitoring your AFR, watch out for lean spots.
Mike

 

[Eniygma]

Sorry forgot to mention it has 550 injectors as well, with stock head and evo e-manifold. I swapped the ECU a second time just to be sure and it does run much smoother with the MT ECU

 

[98TalonTSi]

No fuel control? you are running unhealthy rich then...to the point of messing with an O2 sensor. I mean even a MT ECU with 550s and cams, with no adjustment down low, you're asking for some trouble.