MAFT Pro - N/A install - Translator Mode

[drjonez]

do you have 12V @ the MAF?

do you have the MAF wired properly?

stupid questions i know, but sometimes it's the simple things that throw ya....

 

[CRE]

do you have 12V @ the MAF?

do you have the MAF wired properly?

stupid questions i know, but sometimes it's the simple things that throw ya....

I do have +12v at the MAF.
It's all wired per the diagram above, except I still need to move the grounds.
They're not stupid questions. More often than not, it is the little things which get us.

 

[drjonez]

yes, but is the MAF wired CORRECTLY? (referencing my post #34)

 

[CRE]

Yup. All except for pin #2 on the 6pin harness which Bob said not to connect in post #11.

 

[drjonez]

Yup. All except for pin #2 on the 6pin harness which Bob said not to connect in post #11.

yeah, no need w/4.80.

 

[turbobob]

Dr.Jonez, Bob,

A couple questions. How much current should the LS-1 MAF draw when the engine's off? I have a feeling the first thing I need to look at is the MAF. Regardless of how Aux1 was connected shouldn't I have still seen something in the monitor for FI? Yes, I know it's presumptious and that such things are entirely dependant upon the design of the circuit. But what's the harm in being hopeful?

1 - 3 amps. (an estimate)

yes, you should see something on FI. Do you have the jumper connected correctly?

With the engine off, you may not see anything, but any airflow at all brings the MAF output up in to the readable range.

B

 

[CRE]

1 - 3 amps. (an estimate)

yes, you should see something on FI. Do you have the jumper connected correctly?

With the engine off, you may not see anything, but any airflow at all brings the MAF output up in to the readable range.

B

The reading from FI has never so much as flickered... whether I'm at idle with both the MAF and stock AFM connected (when the MAFT Pro's output was not connected to VS) or when I connect just the MAF and it's piping and try to start the car. This is why I'm thinking the MAF is the issue. I'll check its power consumption when I move the grounds.

I don't think I know anyone with a compatible MAF in my area or I'd try swapping in a known good one. Does the Chevy S10 Blazer '99 with 4.3 Vortec V6 use a compatible MAF?

 

[CRE]

Wooooo! I've got signal!

I took a few minutes to go over the wiring in the parking garage at work. I switched all the grounds over from E2 to E1. I don't know if one of the splices was bad or if the groundwasn't passing enough current.

Now, the car will start and idle. If I try the throttle you can hear it rev up for just a split second then it all falls flat and dies.

The wiring is now identical to the diagram I've been updating above. You both have the settings I'm running with at the moment as well. What do I need to look at next? Fc is grounded to E1, BTW. TPS (VTA) registers .52 - ~3.5.
I double checked the Fc ground, and the connections to Vs, VTA and IGt.

I really hope it's just software from here on out.


____________________________EDIT__________________________

Hey guys, I think I may have realized the issue. I'll let you know when I have a minute to investigate it further.

This will set the fuel pump into action with the ignition right? Are there any negatives to this?

 

[drjonez]

Wooooo! I've got signal!

I took a few minutes to go over the wiring in the parking garage at work. I switched all the grounds over from E2 to E1. I don't know if one of the splices was bad or if the groundwasn't passing enough current.

Now, the car will start and idle. If I try the throttle you can hear it rev up for just a split second then it all falls flat and dies.

The wiring is now identical to the diagram I've been updating above. You both have the settings I'm running with at the moment as well. What do I need to look at next? Fc is grounded to E1, BTW. TPS (VTA) registers .52 - ~3.5.
I double checked the Fc ground, and the connections to Vs, VTA and IGt.

I really hope it's just software from here on out.

interesting....glad it's finally working. any codes after it dies? sounds like there isn't anything being output to the ECU....what is Fin? what is Vout1? you might want to switch over to Vout2 after your mis-wire incident, it is possible you fried Vout1.

____________________________EDIT__________________________

Hey guys, I think I may have realized the issue. I'll let you know when I have a minute to investigate it further.

This will set the fuel pump into action with the ignition right? Are there any negatives to this?

yup, grounding Fc will turn the fuel pump on w/ignition. i assume toyo did it as a safety feature......so if the engine dies, the fuel pump dies.

 

[CRE]

Okay, I've got it running. Fc is the second pin on the AFM harness as per the TEWD NOT the first pin as indicated in the TSRM.

I'm running VERY rich! The only words to describe how it's running and idling are: it chugs. Misfiring perhaps?

I'm getting codes 31 and 24, unfortunately I can't remember if I cleared to codes after last night's attempt. If I feel energetic in a little bit I'll go try it again and see if the 31 comes back.

Any thoughts on the fuel? Can Tunerpro log a run so I can post it for you two to look at? If so, where's it save the file?

EDIT: ^^^Nevermind if it can or can't log, I know it can. If I locate the file and post it can you guys help me understand what's going on?

 

[CRE]

Okay, here's the log:

CSV: http://www.fadingworld.com/Supra/initial.csv
ADL: http://www.fadingworld.com/Supra/7M-GE LS-1 Datalog1.adl

I'm not sure if this just indicates that there are a number of setting changes which need to be made or if there something wrong with some of the hardware (MAF or MAFT Pro). Let me know what you guys think!

I got rid of the code 24 (2.2K resistor, as usual), I'm still getting code 31.

Thanks!

 

[jetjock]

CRE, dunno much about the Maft but your N/A TCCS requires an analog signal on the AFM input. Since the Maft also works on turbo cars (which require a digital signal) are you sure it's configured right? What do you have across pin KS on the ECU and E2? The signal must be below 4.8 vdc and above .1 vdc for the ECU to accept it as valid. Anything outside those ranges will generate the code

 

[CRE]

The wiring diagram and setting I currently have configured are all posted in this thread. For the TCCS the Maft Pro's Aux Output 1 supplies the needed analog signal.

Which pin is KS? Is that the same as VS? Look at the pinout above for the pre89 N/A ECU pinout I'm referencing. Looking back over the log the Aux1 output to VS stays between .28 and about 4.... never reved it real high as it's running so poorly.


EDIT: and thanks for checking in on this, not too many interested in this setup at all.

Here's a snapshot of the graph from the log:
http://www.fadingworld.com/Supra/LogPt1.jpg

 

[jetjock]

Oops, sorry. I'd yanked out the turbo ECU book. Yeah, VS is the AFM input for the N/A. KS is for the turbo.

The ECU should be happy with anything between the limits I mentioned. When I say happy I mean no code. VS still needs to accurately represent airflow but I'm only focusing on the code. Interesting the signal would be within limits and still trigger it. Makes me wonder about the log. Hard data from a measurement would be better. Might be time to break out the meter.

 

[CRE]

I'm done digging around under the dash until some of this F@@#%$%^$#@%^&@%$ing snow melts!!!! Have I mentioned lately how much I HATE SNOW?!

Um, sorry about that.

I suspect the code might also have something to do with the fact that there's no longer a draw on VC. The TSRM also mentions VC as a possible cause.

 

[jetjock]

Yeah, Denver has been the shits lately. You should try flying in it. Hang on...I'm scanning this thread. Back in a bit....

Ok. Like I said I don't know much about this gadget but it's not hard to see how it works when I look at what it connects to. If the wiring is right configuration seems to be the key. We may need turbobob and the good doctor back in here.

Re VC: It's the 5 volt reference for all the car's analog sensors. Since you're an electronically savvy guy here's the scoop. The way the diag system works is there's internal pullup resistors across VC and the signal to be monitored. If there's a short the line goes to ground, if there's an open the line goes high to +5 vdc but as long as it's within .1 to 4.80 vdc the TCCS judges it as valid. There's also a series input resistor. In the case of VS I don't see why VC would cause a problem.

Btw, how are you keeping the fuel pump on? By shorting the control line to ground? Ugh, not safe in a crash.

 

[CRE]

I'm not completely following, but I suspect you're suggesting something I was thinking of earlier. Lack of draw on VC is causing it to go higher than spec and as such it's throwing a code? If so is this a situation where I could simply supplay a static load on VC and not have to worry about it or does the load need to be dynamic (on par with VS)? In which case a simple circuit is in order. You know the TCCS a hell of a lot more in depth than I. Any suggestions are VERY welcome!

 

[CRE]

Btw, how are you keeping the fuel pump on? By shorting the control line to ground? Ugh, not safe in a crash.

Only for the moment. I'm planning on building something regulate it properly, perhaps feed off the TPS' IDL switch.

 

[jetjock]

The ECU sends out 5 vdc (VC) to power all the analog sensors. Coolant, TPS, AFM, etc. Inside the ECU there's a resistor directly connected across this 5 volts and the sensor input being monitored, in this case VS. This pull up is sized high enough in resistance that it doesn't have an effect on the sensor involved. However if the sensor or it's wiring should short to ground VS would also be pulled to ground. The pull up protects the main 5 volt power supply in the ECU by limiting the current but in addition to this function if the sensor or wiring opened VS would be pulled up to VC through the resistor.

All these analog inputs go through an A/D converter where they get changed to TTL or CMOS digital levels. The box is after all a computer. The diag software in the ECU knows enough to report a sensor input below .1 or above 4.8 vdc as bad.

The TSRM mentions VC only because a loss of it would result in loss of airflow signal (and a whole bunch more if it was system wide). I don't see why you'd need to externally load it. It shouldn't care what VC is doing unless VC is being used to supply power to the AFM and it's lost. All theory aside, as long as the VS input is between .1 and 4.8 vdc the TCCS will be happy diagnostic wise. Why yours is and yet you still have a code 31 is what's puzzling.

The FP thing needs to be addressed. Turbo cars don't use the AFM for pump control. They use the ECU to control it by looking at the CPS signals. An option for you is to do the same thing by installing a tacho-relay, often called an rpm relay. Used on many cars and cheap to find. The Bosch ones come to mind. It'll kill the FP as soon as it sees a loss of rpm from the igniter. In theory should be easy to install. An added benefit is it'll prime the fuel system before the engine is cranked, the way it should have been designed all along.

 

[CRE]

I suspect that if it's nothing to do with load monitoring on VC then it must actually be the fact that the MAFT Pro takes a couple seconds to boot up and supply VS a signal.

So I could just feed VS .1v and the code should clear up and it *shouldn't* have any adverse effects on the signal coming from the MAFT Pro, right?

EDIT: Do you have any examples of how a tacho-relay is connected? Is it just a clamp on the distributor line and the rest wired like a relay?