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Still Nissaning
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825 Posts
Discussion Starter #1
Ok, I have been toying around in my mind for years with the idea of putting a MPFI manifold from a GA16DE on my GA16I, making it a GA16SE. I have now set this project in motion to see if I can get it to work.

For starters I bought a complete manifold with all sensors and solnoids form a 1994 GA16DE...


I happened to have a spare manifold sitting around from the GA16I, so I sat the two side by side...


As can be seen from the pictures they are very similar, this was encouraging.
I next went down to the auto parts store and bought a new gasket for the GA16I, and sat it on the MPFI manifold to see how close they were...



As can be seen from the pictures there are three holes that do not allign up, and they are about 0.18 inches off.
I will be taking the manifold to the Bridgeport milling machine and milling some slots to allign up to the engine block.
This project has allready started to get me excited to get it going.
I will keep an update as I have progress on this roject.
Bob
 

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Apprentice Technician
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784 Posts
you're making me so jealous right now...

but the stuff you're finding out now will help me out so much!

you can already see how much better the DE manifold will flow air. are you going to port match the GA16i head? and i can see that your fears about the coolant jackets can be forgotten as the coolant jacket port is identical.
 

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Still Nissaning
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825 Posts
Discussion Starter #3
you're making me so jealous right now...

but the stuff you're finding out now will help me out so much!

you can already see how much better the DE manifold will flow air. are you going to port match the GA16i head? and i can see that your fears about the coolant jackets can be forgotten as the coolant jacket port is identical.
On my first go around with the pulsar I am going to leave the head exactly how it is, partly because I want to be able to put the old manifold back on if necessary, and partly because I am impatient and want to get it going ASAP.
I am very releaved that the coolant jacket is the same, and as far as I can tell so are the routing of the coolant lines through the intake.
My next concern is with the wiring harness, I do not want to mess up the stock one too much, so I will try to re-use as much of the MPFI harness and some of the harness I have from the extra TB manifold to make an adapter harness.
I measured the resistence of the injecters on the MPFI manifold (11.5 OHMS each), and the injector on the TB manifold (1.5 OHMS) so it looks like the GA16I computer will be able to drive all 4 in paralell.
Bob
 

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Still Nissaning
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825 Posts
Discussion Starter #5
Update...
The next problem I ran into is the coolant lines. There is one line that is a different size on the MPFI manifold from the rear thermostat housing, so I had to make an adapter to hook it up. I also had to buy a new gasket for the multi port manifold so I could modify it to fit the new pattern.
Sorry, I don't have any pictures of it yet, but I will soon.

I am now in the phase of the wiring. There are a few problems I forsee with it thus far, but I think with a little work I can get it running.
The most trickey part is the MAF and how to wire it, and the lack of a throttle switch on the MPFI manifold. Also there does not seem to be a temperature sender for the gauge in the dash (I think the newer cars use a signal from the computer)
Everything else on the wiring looks like it will be a direct splice over.
I still need to hook up the throttle cable, and the pipe from the exhaust to the EGR, then I will be ready to start it up.

Oh,
The TBI injector is 1.5 OHMS
the MPFI injectors are 11.5 OHMS each
 

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Still Nissaning
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825 Posts
Discussion Starter #7
holy crap! so in a week we've gone from theory to just about ready to fire it up. that's freaking incredible....

how much simpler or more difficult do you think this swap would be using the b13 ECU instead of the GA16i ECU?
ITS ALIVE!!
I could not sleep for the anticipation, so I got up early this morning and put it the rest of the way togather!
Let me just say one thing...
Holy Holy Holy crap!
Even without the TPS hooked up, or the proper throttle cable (I can only get it to open about 3/4 open) it flys.
I cannot believe how easy this was and why oh why did I not try it before.
Here are some pictures of the franken car as it sits now...








Now comes the rest of the work in fine tuning the details.
As for the B13 computer you would need the harness from the engine and chassis to get it to work. I think there was also someone (recycledtoddler?) on here that had sucessfully done a system where he piggybacked the B12 and B13 ECU and installed a GA16DE sucessfully.
 

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Apprentice Technician
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784 Posts
OH MY GOSH!!! BOB I LOVE YOU!!!!!!!!!!!!!!!!!

i know that with using the b13 ECU it will basically like doing the wiring part of an engine swap. i'm pulling an entire GA16DE + harness/ECU for my manifold swap. BUT, let me know how it runs with the GA16i computer, because i may just get a standalone and use the existing ECU.

oh, as for the performance, how did it change throttle response? acceleration? and speed?

and shall we officially dub this engine the GA16E???

this needs to be stickied!
 

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800+ posts
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822 Posts
Amazing progress in the span of a few days! I second a sticky! Perhaps you could work on a more detailed write-up (once you get all the kinks out) so other members can do this conversion.
 

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Amazing progress in the span of a few days! I second a sticky! Perhaps you could work on a more detailed write-up (once you get all the kinks out) so other members can do this conversion.
Nathan! good to see you're alive! this is amazing news, is it not?? check your youtube messages.
 

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Still Nissaning
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825 Posts
Discussion Starter #12
I still need to work some bugs out, like the TPS. It does not seem to want to idle very well sometimes, and it idles fine others. I think the resistance of the two TPS's are off.
After getting some of the sensors wired up properly it seems to have yet a little more power, but also is more hesitant to change RPMs with throttle posistion. I will have to think about it for a while more... as it is now I would not consider it to be a daily driver (too finicky)
I will be very busy with work this week, so I may not get to play much untill this coming weekend.
After I get everything worked out to my satisfaction I will be doing a write-up with pictures for those who feel adventurous.
Bob
 

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Apprentice Technician
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784 Posts
I still need to work some bugs out, like the TPS. It does not seem to want to idle very well sometimes, and it idles fine others. I think the resistance of the two TPS's are off.
After getting some of the sensors wired up properly it seems to have yet a little more power, but also is more hesitant to change RPMs with throttle posistion. I will have to think about it for a while more... as it is now I would not consider it to be a daily driver (too finicky)
I will be very busy with work this week, so I may not get to play much untill this coming weekend.
After I get everything worked out to my satisfaction I will be doing a write-up with pictures for those who feel adventurous.
Bob
yeah, this is why i want to use the DE ECU and sensors. but bob, you've already done so much, i seriously applaud your progress.
 

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this is truly awesome!! I am very happy for you bob! I just got the pulsar home tonight, and it isnt as rough as I had thought. I will get pics tomorrow and try to get them loaded up here.


keep on pushing with it Bob....its coming along nicely.
 

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Still Nissaning
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825 Posts
Discussion Starter #15
The New TPS that came on the MPFI manifold is not compatible with the GA16I computer. I am working on making an adapter to install the stock TPS on the MPFI manifold. I think after I get this done I will be in the green.
I will keep you guys updated.
 

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Still Nissaning
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825 Posts
Discussion Starter #17
How did you get the injectors to fire in the right sequence? That is the only issue I can't seem to work out in my head on how it all works together.
I have it firing all 4 every time, that is how the majority of the engines I have seen work. Even though they have an independent wire for each injector from the computer the computer usually just fires all 4 at the same time.
I think I have fixed the TPS problem, I made an adapter for the old one so I can use it on the MPFI throttle body. I will see when I get home how well it works.
I hope this will conclude the problems with the sensors and wiring.
 

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I have it firing all 4 every time, that is how the majority of the engines I have seen work. Even though they have an independent wire for each injector from the computer the computer usually just fires all 4 at the same time.
I think I have fixed the TPS problem, I made an adapter for the old one so I can use it on the MPFI throttle body. I will see when I get home how well it works.
I hope this will conclude the problems with the sensors and wiring.
depends how old the system is. newer ones may have sequential injection. but i think you're right about the B13 GA16DE injectors firing at the same time

let us know how the adapter works man.

got a question, what did you make the gasket out of, or did you use a GA16i gasket, liquid gasket, or just some RTV?
 

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Still Nissaning
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Discussion Starter #19
I think the debugging is drawing closer to a finish!
Ok I got the TPS/Throttle switch from the TBI manifold adapted to the MPFI manifold. I can get it to idle now, and the throttle response is much smoother. After some time of running the engine to get an idea of it's quirks (it still has a few that bother me) I decided to pull the codes from the computer to see if it noticed any issues. I am getting a code 12, which by my trusty Haynes manual says it is the MAF. I will be testing the MAF with a volt meter, and putting the two (old and new) side by side to see if I can find a difference between them.
As it runs now I would say it is a bit rough at idle, and there is a small lag before it starts producing power right off of idle. All in all I think It is reliable now, just not as smothe as I would perfer.
Once I figure out the MAF and get the computer to go into closed loop cycle I want to see how good the mileage is, as well as how smothe I can get it to run.
As for the gasket, I just bought the gasket for the 1993 sentra (metallic gasket) and cut with tin snips the area where the 3 bolts had changed so it would fit the head.
 

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I think the debugging is drawing closer to a finish!
Ok I got the TPS/Throttle switch from the TBI manifold adapted to the MPFI manifold. I can get it to idle now, and the throttle response is much smoother. After some time of running the engine to get an idea of it's quirks (it still has a few that bother me) I decided to pull the codes from the computer to see if it noticed any issues. I am getting a code 12, which by my trusty Haynes manual says it is the MAF. I will be testing the MAF with a volt meter, and putting the two (old and new) side by side to see if I can find a difference between them.
As it runs now I would say it is a bit rough at idle, and there is a small lag before it starts producing power right off of idle. All in all I think It is reliable now, just not as smothe as I would perfer.
Once I figure out the MAF and get the computer to go into closed loop cycle I want to see how good the mileage is, as well as how smothe I can get it to run.
As for the gasket, I just bought the gasket for the 1993 sentra (metallic gasket) and cut with tin snips the area where the 3 bolts had changed so it would fit the head.
that is def coming along well, and quickly. Once running smoothly, will you be able to get some vid of how it is running for us?
 
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