NA-T Map Ecu problems!

[Jargon]

I'm still having extreme problems with my na-t map ecu on my supra. I have the map ecu installed. It appears to be installed correctly as I have had others check my wiring. Basically the car has problems when the map ecu vac line is connected. The car has trouble idling, it will go up and down from 400rpm to 1200rpm and sometimes fall enough to stall it. Also if I try and give it any throttle, it will bog heavily and cut out. If, however, I disconnect the vac line it will idle at around 1800rpm solidly. I not sure if this is something wrong with the map ecu or what. I have tried replacing my upgraded 440 injectors with the stock injectors and its still the same, I have also replaced the spark plugs, the fuel rail, and tried changing out my fpr. I have also upgraded to a walbro fuel pump. I have double and triple checked all the connections around the intake manifold. I also have removed the egr and all the extra vac lines that go with it, incase that was causing the vacuum to be low or something. I have basically run out of ideas, and I really dont know what to do about it. I would like to take it to one of the local shops but they are all backed up and im on a waiting list...if anyone has experience with map ecus and supra na-ts Id be greatful for any advice. BTW I'm OBD1. Thanks!

[Bean]

I'm not familiar with the MAP ECU... but think your TPS settings might have anything to do with it?

have you done a leak check? basically plug the system and pump air into it with a bicycle pump?

[dejacky]

Jargon,
have you tried posting in the Power House Racing section of supraforums.com? They have long threads of persons with map-ecu difficulties and solutions. :beer:

[Jargon]

hrm will have to try the bicycle pump trick. Yeah ive tried talking with phr they werent much help...

[turb0terr0r]

man, i have yet to hear a sucessful map-ecu story on a obd1 supra.

i hope you get your issues resolved.

jay

[dejacky]

Obiwan told me OBDI + map-ecu can work he's has tuned several that work perfectly. Hopefully he can tune my car to avoid all these glitches :drama: .

[ISC300]

Sorry to bring this up, but I really want to know more fuel mangment beside SAFC, Standalone ? I post before about the Rom tunning but I didn't get any detail about it... can we list all types of fuel magment we can use on our 2jz and what's the limit on each setup


SAFC- what 's the max cc injector
- SAFC and VPC combo

Standalone .....

etc.......

[ISC300]

oh by the way, anyone try the new E-manage with all the new feature ( any size injector ....etc)

[WhiteBlazze]

Sounds like you may have some vacuum leaks, or IAC issues. triple check the wiring too, only takes 1 wire in the wrong place. Are you sure the vaccum line to the map-ecu is not crimped in any way?

Map-ecu can be tuned on a obd1, its just a little more time consuming on getting the fuel tables right. The karmen style is very touchy and changes the to fuel tables should be made in increments of 5 or smaller until they are set where u want them to be. On OBD2, it's a bit more forgiving and you can make larger increment changes to get it tuned quicker, yet the OBD2 gives a lean/rich spot in certain areas.



As for ISC300's question..


The SAFC and SAFC2 on a stock maf will max out on 440cc. You could use 525, but youll be rich throughout the whole a/f area.

The SAFC and SAFC2 on the Lexus LS400 maf upgrade will do up to 550-620.

I don't know much about the combos, but I am pretty sure you can run atleast up to 750cc easily. I have seen others with the safc/vpc/gcc do 750


As for map-ecu, and any standalone, your pretty much limitless on how big you can go.

[ISC300]

thanx for the input

[SuperRunner]

I have had great success with the MAP-ECU and OBDI.

My bet is your fuel is way off. You got a wideband? Post your table and lets see what you are trying to run at idle.


I just got 300RWHP with 11.4-11.7 A/F's the entire boosted range. And drivabilty...idling, and starting is as good as factory.

[dejacky]

Just get Gamimnon to tune it..he's "da man."

tuning in and around the texas area on map ecu and VPC SAFC2 setups, obd1 obd2, TT or any other setup with a map ecu or vpc. you can contact me at my email. parkerrx@mail.utexas.edu :bowdown-0

[mogallo]

Man i swear...... AEM is the solution to all problems!!!! (Except my boost creep) :D

[1st gen v300 turbo]

Hey I am having that same problem I just have not disconnected my vacuum sensing line from the map ecu. I have done all the reading from the map ecu to my connection and found that the map ecu is good but there is a vacuum switch left side of the injector rail that runs from the egr valve and acts as the vacuum modulator. The switch handles both function via ecu. I just replaced the switch and I will let you know if this cures my problem. Make sure you do not have the iat sensor connected up wrong. For get the sensor and soider a 2.2k resistor in its place. This serve better for tuning because it keeps you timing and afr steady. The resistor needs to be soider to the blue/white stripe wire and then soidered to the solid brown wire which is the ground. This takes care of iat sensor.

[Bean]

The trouble with using the resistor is that your ECU will no longer compensate for temperature differences; and cool and warm air hold a considerably different amount of oxygen. Maybe tune it without the IAT and then do a final tune using the IAT?