maft pro experts, help on wires and installing

[kracin]

ok, this isnt in a supra, its in a cressida thats had a swap, using the supras ecu, engine, ect, all that. so basically running the exact same as a mkiii, the car has plenty of mods to it, was running an safc and i wanted the maft pro to eliminate the maf and isc lines, and to be able to get a better tune out of it and remove the fuel cut as well so i can start running race gas.

started the install today, but i have a problem. the car will start, and run, but when revving (havent tried to drive it yet because of the problem), it wont rev past 2500 and will have stutters up until then, like the afm is disconnected, also the CEL is on the whole time since the afm is disconnected.

tried reconnecting the afm, setting the f-in back to 1 where it was originally just to see, and started it back up. and it would rev fine then, still didnt try to drive because this isnt the way its supposed to run and i dont want to fuck up the engine with bad timing possibly.

also, the KS wire it says to tap into, but whats the correct way to hook this up, it might have been done wrong on my side, having connected into it by just tapping in and leaving the wire whole, im thinking it may need to be disconnected and then have the maf connect to the ecu side of the wire since there isnt supposed to be an afm when its all said and done

any help is appreciated as to why its happening like this.

Ian

 

[drjonez]

Sounds like you didn't change the settings in the MAFT pro correctly....list 'em.

If you left the AFM connected while attempting to run speed density, that may have been the problem. No problem just tapping KS, just as long as you disconnect the AFM.

 

[kracin]

i followed the settings on the maftpro setup sheet that was in the box with the maftpro you sent to the T, disconnected the afm, and it still did it. just being safe that it is ok to have the yellow, the gray, and the 2 o2 sensor wires disconnected right? i went out and checked it again and it did the same thing.

and by tap, you do mean leave the KS wire whole, not like the safc is, and just run the maftpro to it? id think that the disconnected maf would send a signal to the ECU if the ks wire was left in tact?

thanks, ill double check to be safe, but i know it had it right the first time... ill get a list of the stuff that its set at soon up, until then, would having a bad vacuum source cause this as well?

 

[kracin]

ok, thanks for the help so far drjonez, heres the lift of all the settings and what they are currently set to with the maf disconnected trying to run the car, giving the afm problems as if it still wants it.

veh sel: 0
# of cyl: 6
disp 3.0
airfl source 0
map source 0
dens srce 0
baro mode 1
f-out mode 4
vout1 mode 0
vout2 mode 0
afr source 0
f-in mode 0
aux1 mode 0

under system now
main scale 0
vout1 2.5
vout2 3.6
afterstart 0
lo load pt 36.4
mid load pt 100.1
high load pt 143
f out max 0
tm base 0
tm correct 1.27
af trdelay 0


like the sheet says, all air temp, aux trig, and af tune are all at 0/0%

tps enrich .5
tps decay .8
tb size 7
map enrich .4
map decay .8
map tps min .4

the manifold temp was reading good
the manifold absolute pressure was reading good.. although reading a little high (not registering enough vacuum maybe) when idling, it was around the high 70's. and the tps was reading ok, it was around .5 released, and 3.5 pressed in all the way.

let me know if i missed any reading here, and what is wrong.... i looked into the book and it said 34 for the f-in for a mkiii with no maf??? confuses me considering the sheet says 0... hopefully you have some insight, thanks!

Ian

 

[7MGTEsup]

Your manifold pressure is 70+kpa while idling?? Mine is around 30kpa at idle sounds to me like you have a large leak somwhere. What does the map sensor read with ignition off?

 

[kracin]

near 100 while off, the idling was just abnormal. thats why i was thinking i may have a bum vacuum source for it as well and need to try another, but thats not going to cause the afm to send a fucked signal.. is it?

 

[drjonez]

near 100 while off, the idling was just abnormal. thats why i was thinking i may have a bum vacuum source for it as well and need to try another, but thats not going to cause the afm to send a fucked signal.. is it?

A poor MAP signal could certainly cause poor KV output.

 

[kracin]

A poor MAP signal could certainly cause poor KV output.

ill check out the vac line tonight and see what may be causing the poor signal, thanks for the help ill keep updating as I rulet hings out

 

[kracin]

ok checked it out

the vac line was bad, go figure..

now off its 89, and on its 16-18 MP

but the problem is still there.. with f-in set to 0 and all the settings as shown above, it still throws the afm code and wont rev past 2500.

any more ideas? ive double checked, and triple checked all the wires and connections, they are all soldered in place right now. this is really stumpin me, i dont know what else would keep this from workin like it should.

 

[kracin]

ok, i have a conflict here if anyone i still reading this thread considering this is my third update post in a row.

the diagram from njsupraa70 shows the brown wire (air temp) being tapped into the tha wire on the ecu. but the directions on the sheet say to splice the brown wire into the ecu side of the tha wire...... i dont have the money to fry anything or the time to have the car down, its running on stock tune right now which is ok, but can anyone clarify how this wire gets hooked up..... should the brown wire tap into the whole tha wire, or should the tha wire be CUT and then have the brown wire connected only to the ECU side of the wire??? thanks to those who have replied already.

 

[kracin]

ok, so i cut the THA wire with the maftpro on f-in 0, unhooked the afm, and started it up... didnt make a difference, but id still need to know which way this wire gets good up, and if theres any other special ways to hook up any of the other wires??

 

[7MGTEsup]

You need to cut the THA wire and hook up the wire from the MAFT pro to the ECU side of the loom. Basically what this does is send a constant signal to the ecu so it thinks the inlet temp is 68*f.

I take it when your getting a code its a code 31? Are you sure you looked at the right wiring diagram for your year of ECU?? Are you sure you were looking at the plug from the right direction when you pinned it out??

 

[kracin]

yes, im sure. i had an safc hooked up prior to this, and some of the pinouts on it are the same, the other concern. just wondering what other things i should be looking at double.triple checking in the event that it still throws codes and wants the afm connected to fix the problem??

would the temp reading being wrong throw an afm code as well? or am i looking at something else, and is there any way to test the actual sensors, the gm map and the iat sensor... and is there a way to test the maft pro itself to make sure its still good? it was sitting in the box for a while after i bought it from dr jonez, but still brand new, so i have no clue.

thanks for the replies again, trying to get to the bottom of this soon!

 

[JimR]

Codes for a missing airflow signal and missing air temp signal are normal with the Maftpro. They are caused because the ECU checks for those things before the Maftpro has a chance to boot up. Once the maftpro boots, it supplies those signals, but the codes have already been set.

Looking at your settings listing, it appears that you are running v4.40 of the software. The first thing I would do is update to v4.80, and go from there. It will give you names for many of the settings instead of just numbers.

 

[7MGTEsup]

Codes for a missing airflow signal and missing air temp signal are normal with the Maftpro. They are caused because the ECU checks for those things before the Maftpro has a chance to boot up. Once the maftpro boots, it supplies those signals, but the codes have already been set.

Looking at your settings listing, it appears that you are running v4.40 of the software. The first thing I would do is update to v4.80, and go from there. It will give you names for many of the settings instead of just numbers.

Jim as far as I'm aware you should only get a code 24 (IAT)

 

[JimR]

Jim as far as I'm aware you should only get a code 24 (IAT)

Ah right... I got my codes a little mixed up. I was actually thinking of code 35, but that's when you do the HAC (High Altitude Compensation) mod and let the Maftpro supply the signal, which is the same time-delay problem as code 24.

Those two codes don't really bother me though. In future, I might get around to putting resistors in the right places to fix them.

 

[kracin]

ok, the wires are all hooked up right, and all the settings are correct in the maft pro. i need to find out if my sensors are bad or if the maft pro itself is bad, does anyone know the right voltages per output for the maft pro so i can test it? dont know what could be th eproblem, because the problem seems to still be that the ecu isnt accepting the removal of the afm.