Maft Pro question

[Justin]

The guy who bought the 88T from my Dad and I just installed his MAFt Pro and LC1. He got the unit installed but cannot get it to run in speed density mode... it'll bounce around 500 RPMs just like it does when the AFM isn't plugged in... Once he plugs the AFM back in and unplugs the speed density harness then it runs fine again...

I don't have any experience with the MAFT Pro and cannot find a decent instruction manual online... anyone have an idea what the problem may be?

he's on his way home right now so he should be able to chime in if i missed anything soon.

 

[smokey]

look for dr jones in the members area, in his signiture he has several links for this

 

[Justin]

look for dr jones in the members area, in his signiture he has several links for this

I read them all, didn't see anything relevant, did I miss something that you saw?

 

[dbsupra90]

just as a suggestion, you may want to make a better title for this thread. there are already tons of "maft pro question" threads on here and often dont get many views. something like- "speed density problem w maftpro" would be a lot better.

 

[LEGNA]

The guy who bought the 88T from my Dad and I just installed his MAFt Pro and LC1. He got the unit installed but cannot get it to run in speed density mode... it'll bounce around 500 RPMs just like it does when the AFM isn't plugged in... Once he plugs the AFM back in and unplugs the speed density harness then it runs fine again...

I don't have any experience with the MAFT Pro and cannot find a decent instruction manual online... anyone have an idea what the problem may be?

he's on his way home right now so he should be able to chime in if i missed anything soon.

Did he set the pro to... speed density...and is he sure the rest of the basic parameters are set right

 

[red88suprat]

how do you set the pro to speed density?

 

[Justin]

Did he set the pro to... speed density...and is he sure the rest of the basic parameters are set right

That's what I think the problem is... I had him read off the settings as i looked at them online and they were the same...

I think I'm missing something online though, what to change where to have it read off the MAP sensor...

 

[Justin]

just as a suggestion, you may want to make a better title for this thread. there are already tons of "maft pro question" threads on here and often dont get many views. something like- "speed density problem w maftpro" would be a lot better.

You're right, I should have... I tried to edit the title I couldn't... Thanks

 

[turbobob]

Post all the config and setup settings.

Look at the following sensors

RPM
MP
TPS
FO
IAT

Tell us what they read

B

 

[Justin]

Post all the config and setup settings.

Look at the following sensors

RPM
MP
TPS
FO
IAT

Tell us what they read

B

I'd love to but I am relaying all this for a friend...

I think dr. j helped me figure out the problem... if i remember right, when matt was reading the sensors off to me I think he said fin and fout were both 0...

what I don't know is what fin should be... 20 or 34...

fout is okay to be 0 correct? simply meaning that it will not cap output?

 

[turbobob]

FIN is freq in, in speed density mode you don't have the MAF so this should be 0.

FOUT is frequency out, the MAF signal to the ECU, this should be 0 when the engine is off, and NOT zero when the engine is running.

MP is the Manifold Pressure, 99 or so, engine off, 30-50, engine idling.

 

[Justin]

Okay, we're going to kind of start over here.

I just rewired the maft pro, soldering everything.

Here's what happens...

With the AFM Plugged in, and the Pressure sensor harness UNplugged the car runs fine.

With the AFM UNplugged and the Pressure sensor plugged in, the car runs like shit then dies.

With the AFM plugged in and the Pressure sensor plugged in the car runs like shit and dies.

he says he's got it to run once or twice, but at random. That's why I soldered everything, because I'm not a fan of ttaps...

any help while he's still in town?



edit: can I TAP into the AFM wire, or do I have to CUT it?

 

[Justin]

FOUT is frequency out, the MAF signal to the ECU, this should be 0 when the engine is off, and NOT zero when the engine is running.

while the engine is struggling to run, Fout is 0.


So the real question here is why is the MAFT pro not outputting a signal?

While the pressure sensor harness is unplugged MP is at 1.1 when i plug it in it goes to 32~ then the car dies.

 

[turbobob]

You have to cut the AFM wire if you want to run the AFM at the same time as the pro (so-called AFC mode). Might make sense to do it that way, so we can run from the AFM/MAF and troubleshoot the rest of it.

When you cut the AFM wire, the Yellow Pro wire receives the signal from the AFM, the Green Pro wire sends the new signal to the ECU. Then you can set F out mode to 0, and run in AFC mode. Then FI is the frequency in....

FO (Freq out) is calculated from MAP, RPM, IAT, and displacement.
What do MP, RPM, MT (IAT), TPS read? Displacement is set in the config page.

How did you configure the unit? What version are you running?

Bob

 

[Justin]

hey man, the guy i am trying to help is red88suprat. he says he's already given you the answers to those parameters... if that helps any.

MP: When the pressure harness is plugged in, ~30 which seems wierd to me
MT: again, when the harness is in it was 137 or something in that range
RPM: 700 or so
TPS: .55 upto 5
Displacement: 3.0


like i said though, when i start the car and the pressure sensor harness isn't plugged in it runs fine, then when i plug the harness in, it dies very shortly after

 

[turbobob]

hey man, the guy i am trying to help is red88suprat. he says he's already given you the answers to those parameters... if that helps any.

MP: When the pressure harness is plugged in, ~30 which seems wierd to me
MT: again, when the harness is in it was 137 or something in that range
RPM: 700 or so
TPS: .55 upto 5
Displacement: 3.0


like i said though, when i start the car and the pressure sensor harness isn't plugged in it runs fine, then when i plug the harness in, it dies very shortly after

MP can be 30 when idling smoothly. if the engine is not running then it should be about 100. If this is not how it is, then this needs to be FIXED.

MT, 137 degrees sounds high to me......

TPS sounds ok
displacement sounds ok

He said the RPM input seems to be working.

So something is off..... Are you sure you have the correct MAP sensor?
Can you measure some voltages for me. The red wire should have 5 volts on it. with the IAT sensor uplugged, the brown wire should have 5 volts.

Bob

You can always hook up the MAF/AFM wiring and run it in AFC mode for now.....

 

[Justin]

MP can be 30 when idling smoothly. if the engine is not running then it should be about 100. If this is not how it is, then this needs to be FIXED.

I wan't sure what the measurement was in, so 30 just seemed off, but good to know what's what its supposed to be.

If its not 100 then its an indication of a boost leak or something to that effect?

MT, 137 degrees sounds high to me......

maybe it was slightly lower, I have a horrible memory... either way, it was registering.

TPS sounds ok
displacement sounds ok

He said the RPM input seems to be working.

Yep.

So something is off..... Are you sure you have the correct MAP sensor?
Can you measure some voltages for me. The red wire should have 5 volts on it. with the IAT sensor uplugged, the brown wire should have 5 volts.

Uhm, I would imagine, its the one that came with the package

Bob

Justin

You can always hook up the MAF/AFM wiring and run it in AFC mode for now.....

The main point of it at the moment is to get rid of the AFM, he's got 550's with the stock AFM... not a good combo



Thank you for your help... I'm pretty impressed with the unit, today was the first time I actually played with one... other than this slight problem, I like it!

 

[turbobob]

Well, in AFC mode you can tune for the injectors, and troubleshoot the speed density stuff......

But, you/he need to figure out the MAP sensor stuff. The Speed density calculation is based on the MAP sensor, so we need to fix that first.

Drop me a PM and we can get into it in depth......

Bob