Auto Trans ECU in a MANUAL?!

[Steaver]

Hey guys, iv been having some issues with my RB20. it bogs at 4000 rpm and slowly gets worse the warmer it gets. i looked at the blue plate in the engine bay. its says the car was a 4 speed auto originally. (its a 5 speed manual now BTW) we looked at the ECU and ran the serial number, and it is an auto ECU. how much of an issue is this and how easy is it to fix? what would be the best option to fix/replace this? is it worth buying a manual ECU? (does a manual even need an ECU?) is there a way to get the auto ECU to work correctly with this transmission? anything will help. i really want my car to run good :'(

[Voodoo_ChildR32]

Have u checked coilpacks, maf, plugs, etc? I ran an rb20det on an rb20de ecu for a month with no issue. I don't think the ecu is your problem. Usually if the ecu is bad, the car won't run at all. Look at the basics first, sourcing out the manual ecu probly wouldn't hurt either. It should just be a plug and play type deal.


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[ToroGTS]

If your issue is strongly related to heat I would first look into your coil packs, plugs, ignitor and secondly resistance test the coolant temp sensor.

I am currently running an auto ecu on a 5-speed swapped rb20. I don't have any major issues and in the past everything ran flawlessly. I believe the management problems I am having now may be more related to leaking capacitors within the ecu. I am planning to get a 5-speed Mine's chipped ecu as I've got FMIC, intake, straight pipe exhaust ect. If you have light mods this would be an excellent option for you as well at about $150-200 and commonly available on ebay.

[Steaver]

iv checked all the plugs, coil packs, maf, ALL that stuff. i can promise you its temperature related, i talked to a guy who has dealt with issues like this and he said that it could be the thermostat. it only does it once its warmed up and the colder it is outside, the longer it takes for it to act up. anyone know where the thermostat is in one of these? and if it could even be the issue?

[RWD_GTR]

Thermostat is inside the metal part of the lower rad hose. Wouldn't hurt to replace it with a nismo unit.

[Skym]

When thermostat fails it can late open (around 95 degrees when tested) and engine gets hotter. Stock thermostat starts to open around 78.5 degrees C and I think fully open at 90 degrees C. Factory engine should idle at 80 degrees C. If modified, sometimes 82-84 degrees C is where it will sit at idle.

Nismo thermostat is for racetrack and opens around 62.5 degrees (need to retune ECU to suit a low opening temp thermostat, or engine will run richer). It opens lower because when under full throttle for long period of time (straight on racetrack) coolant temps spike into 80-90 area thus engine doesn't overheat. With higher temp stock thermostat, coolant temps could spike into 90 degrees C + area.

Auto, Manual ECU's are the same, except manual ECU requires 15 degrees BTDC on CAS and auto ECU requires 20 degress BTDC on CAS. Also Auto ECU kick down tables x2 (when TPS touches idle contact, engine rpm flares up) are different and manual ECU kick down tables use the same figures on both tables. Also auto ECU gets signal from autotrans ECU to pull ignition timing during gearchanges. That's easily fixed via earthing thoses wires, so it turns off error code on engine ECU.

TPS is different on auto engine as well, as it not only sends signal to engine ECU, but to autotrans ECU as well. To know when to shift autotrans, the autotrans ECU looks at rpm and TPS position, then it tells engine ECU to pull igniton timing by set amount and I think that's in autotrans ECU software.

Autotrans ECU is located in the same location as engine ECU, but on drivers side of car.

After fitting Nistune you can copy manual ECU tune, etc to auto engine ECU and will run like a manual ECU.

[Steaver]

Alright so I realize this is a very old thread already but I've finally figured out what was wrong with my car! It was the cam angle sensor. I noticed that it was extremely hot when I was working under the hood so I took it off, put it into a sandwich bag and put it in cold water for a few minutes. Threw it back on and BOOM. Hit 6000rpm without a problem. I took the CAS apart and wouldn't you know it, the spindle or shaft inside was actually cracked right in half. So when it was cold, it would catch a little bit, enough to run alright but once it warmed up, wouldn't touch at all and turned my car into a pile of crap! So there ya go. Hope this can help someone else out. Oh and side note, figured out what it's problem was exactly one year to the day after I bought the car!