4AGE 20v OBDI to OBDII help Options

[igpx12]

What I'm looking at doing is kind of an experiment, obviously otherwise I wouldn't be looking for help. I don't know if this has been considered or done before, if it has can someone point me to a thread here or where its mentioned. What I have going on is a 7afe equipped 97 at200 being swapped to a 4age 20v silvertop. I was looking at running the AE111 Blacktop ECU to get rid of the AFM that the silvertop needed in order to run open ITBs, but having to meet emissions I'm left at kind of a roadblock, or so it seems. Both the AE111 ECU and 7AFE ECU run map sensors in order for that to work, only difference is the AE111 is not able to run OBDII. Soooooooo......

This is what I'm looking for, I have both Engines with all the sensors, ignitors and dizzies. Both wiring harnesses with fuse relays and both ECUs. I know there is the whole set up issue of the 4AGE not being OBDII ready, however if it were possible to say piggy back the ECUs to run the proper sensors and motor functions and to have the 7AFE ECU to run the OBDII side of things for the set up. Kinda of a mindf*&# I know, but it maybe a possibility as a hybrid option to work around for OBDII testing. Technically all the Electronics are there from the 7AFE, Only thing is its not setup to run the 4AGE.

So any ideas/support or knowledge of these systems and possible assistance would be much appreciated.

This post has been edited by igpx12: Aug 7, 2014 - 1:40 AM

[richee3]

I came into this thread expecting to make a post about JOBD and how the 4A-GE can't meet OBDII requirements, but now I'm in for results. It may be as easy as running a handful of wires from the 4A ECU to the 7A ECU, then have all of the OBDII wiring go to the 7A ECU. The sensors all work the same way between both engines so the inputs from the 4A sensors may just work and keep the 7A ECU happy. Of course, the 4A has no EGR so there will likely be a code thrown for that. But hypothetically this is possible, just so long as the 7A can't get a signal out for the timing or fuel trim. As long as those wires aren't connected, it can't feed back into the system. I'm definitely in for results. Please keep us posted.

[igpx12]

I came into this thread expecting to make a post about JOBD and how the 4A-GE can't meet OBDII requirements, but now I'm in for results. It may be as easy as running a handful of wires from the 4A ECU to the 7A ECU, then have all of the OBDII wiring go to the 7A ECU. The sensors all work the same way between both engines so the inputs from the 4A sensors may just work and keep the 7A ECU happy. Of course, the 4A has no EGR so there will likely be a code thrown for that. But hypothetically this is possible, just so long as the 7A can't get a signal out for the timing or fuel trim. As long as those wires aren't connected, it can't feed back into the system. I'm definitely in for results. Please keep us posted.

I know richee3, right? everyone comes into these things expecting to give that as an answer. I many a times have run across that and didn't think much on the issues of the 4A being JOBD set up until I had to deal with the emission laws of lovely 'ol NYS. I'm hoping to progress with this little experiment and maybe who knows..... this could benefit anyone out of CA who wants to do a 4A swap.

[Smaay]

it will never work. ODBI and ODBII are totally different technologies, totally different protocols

[Special_Edy]

Why dont you just run a closed plenum feeding the ITBs.

The point of the ITB is to increase throttle response. When you open the throttle there is a delay while air fills the intake manifold before reaching the intake ports. Since the volume of air between the throttle body and intake port is reduced on an ITB setup, this delay time is shorter. Just build a sealed box to connect all the ITBs fed by an AFM.

Alternatively, you CAN run a map sensor. Either you can connect it to one cylinder, or you can connect a vacuum line or pipe from all four cylinders together. It would also have the benefit of increasing balance across all four cylinders.

On my motorcycle they actually have a hole drilled through the head which interconnects all four intake ports. It increases horsepower 15% over models not equipped with it.

This post has been edited by Special_Edy: Aug 8, 2014 - 3:36 PM

[igpx12]

Why dont you just run a closed plenum feeding the ITBs.

The point of the ITB is to increase throttle response. When you open the throttle there is a delay while air fills the intake manifold before reaching the intake ports. Since the volume of air between the throttle body and intake port is reduced on an ITB setup, this delay time is shorter. Just build a sealed box to connect all the ITBs fed by an AFM.

Alternatively, you CAN run a map sensor. Either you can connect it to one cylinder, or you can connect a vacuum line or pipe from all four cylinders together. It would also have the benefit of increasing balance across all four cylinders.

On my motorcycle they actually have a hole drilled through the head which interconnects all four intake ports. It increases horsepower 15% over models not equipped with it.

Special Edy I was looking at running open ITBs merely as a cosmetic aspect and of course the nice resonating sound from them dragging in air into the engine .

On another note, brainstormed a little tonight and thought about the sensors and how they basically take the power supplied through the ECU and send it back in a variant of that amount (i.e. resistance) to show a proper reading on whatever sensor it is. Basically what if you replaced your sensors in a harness with variable and non variable resistors, would that make the ECU happy and show an all good with the sensor readings so the OBDII setup wouldn't throw a code?

If this were possible, one could simply make a standalone harness for the OBDII based ECU and run it on the diagnostic ports alone and run an JOBD engine with its proper ECU and not have to worry about cross signals, incorrect variables on sensors or the protocol of the two opposite systems fighting eachother.

I would just love to piggy back the ECU and make the 20v OBDII ready, but that is still a thought to and from what Smaay said, it wouldn't work, so just thinking out side of the box.