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ECU ROM Tuning.


Indigent
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For starters, sorry for the long post...

 

I am surprised to see that there isn't any real discussion (that i could find in the search) about chipping the ECU's in these things. There is a ton of info on the 300zx that I have been reading and using.

 

I recently pulled the ROM off of the board in my 90's ECU and started poking around. The setup is very similar to the 300zx maps, so it is pretty easy to navigate.

 

I have a buddy with a 1990 Maxima, who graciously let me dump his ROM as well. I was able to find the Fuel and Timing maps quickly. I basically took those maps and put them in place in the Pathy ROM and crossed my fingers. Considering that they have the same MAF (confirmed by looking at the VQ Map) I wasn't overly worried.

 

The truck started right up, and it was definitely more responsive. I don't have access to a dyno, but considering the official Nissan specs for the Maxima were almost 10HP extra, I think most of that is in the ROM.

 

I still have a bunch of Terrano buddies from when I lived in Japan, so I called my friend Takuya up. He was kind enough to go and get a JDM 1993 R3M VG30E ECU at a junkyard (for about $50) and dump the ROM. He emailed me the .bin file. Aside from the fuel and timing maps, everything is the same in the ROM. The fuel and timing are quite different though.

 

I put that .bin into my ECU and fired up the truck. It seems to have a ton more power. I have a route setup to test my truck when I do any major maintenance (it has nice inclines long straight stretches). There is one incline where the truck *always* shifts down to maintain the speed limit, but it didn't have to this time.

 

I haven't done any real testing yet as far as fuel mileage or as mentioned a dyno, so take this all with a grain of salt.

 

Is there anyone on this board that has messed around with their Pathy's ECU? Is there anyone in the Central Washington area that would like to participate in some experiments with this?

 

Indigent.

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I actually de-soldered the ROM chip from the board. I then put the chip into a ROM reader. The hardest part is the de-soldering, but with some simple and cheap tools it only takes about 20 minutes to get it out. All you need is a solder sucker and a soldering iron.

 

300zx ECU Tuning info. Check that out for starters. It goes into details that don't pertain to our ECU's but most of it is relevant. He talks about the pocket romulator, but that is more advanced that what I need right now. I don't need real-time tracing until I get access to a dyno.

 

I went on ebay and bought a willem pcb 5.0 eprom burner. It was like 40 bucks shipped from Hong Kong. Then I went to www.moates.net and bought a few of the sst27sf512 chips. They are EEPROMs, which means you can write to them thousands and thousands of times and don't need a UV eraser. I got the chip socket off of an old ethernet card I had laying around.

 

This is great to get such quick interested responses from this. I will put up pics and whatnot of my ECU teardown. Maybe start a howto similar to the one in the link.

 

indigent.

Edited by Indigent
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Very curious about this!

 

Say, if this does improve performance, mpg, and shift patterns, how much would you charge to do it to mine? I live in Camas/Vancouver, WA so I could drive up? :shrug:

Edited by kingman92010
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Kingman92010:

I wouldn't charge you for it if you post your results and contribute to the whole thing(well maybe a brew or two, to you know, steady the hand while soldering...) :)

Get your rig in tip top shape as far as engine tuning goes, and establish a good baseline of your mileage.

Remember, I am making no claims as to mileage or HP increase. At this point I am just experimenting, and this *could* theoretically brick your ECU.

 

You will have to provide the chip itself. I would buy one or two from here. Let me know.

 

That offer goes for anyone within driving distance of me (Yakima, WA).

 

indigent.

Edited by Indigent
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Kingman92010:

I wouldn't charge you for it if you post your results and contribute to the whole thing(well maybe a brew or two, to you know, steady the hand while soldering...) :)

Get your rig in tip top shape as far as engine tuning goes, and establish a good baseline of your mileage.

Remember, I am making no claims as to mileage or HP increase. At this point I am just experimenting, and this *could* theoretically brick your ECU.

 

You will have to provide the chip itself. I would buy one or two from here. Let me know.

 

That offer goes for anyone within driving distance of me (Yakima, WA).

 

indigent.

 

All sounds fair. What does "brick your ECU" mean?

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I actually de-soldered the ROM chip from the board. I then put the chip into a ROM reader. The hardest part is the de-soldering, but with some simple and cheap tools it only takes about 20 minutes to get it out. All you need is a solder sucker and a soldering iron.

 

That is the main reason most people don't mess with it. If it were as simple (like with a lot of domestics) as pulling the chip out of a socket and pluging it (or a new/different one) back in it would be more common I would guess. There were 1 or 2 companies out there that would basically do what you are doing, but they made custom maps. You sent them your entire ECU and they pulled the chip, re-mapped it and sent it back to you for $300 or so.

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I eventually want to get to making my own maps. I will need to save up for somethings like a wideband O2 and the pocket romulator. I also need to get on a dyno.

 

I also install a socket to make future edits easier. Like I said earlier, I just yanked one off of an old ethernet card I had in the closet.

 

If there is anyone here in WA that has access to a dyno that would be willing to help, that would be awesome. I want to open this whole thing up so everyone can get access to this info if they really want to. I will work on putting together all of the info I have so far during this weekend.

 

If anyone has any other Nissan tuning experience please chime in!

 

indigent.

Edited by Indigent
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For starters, sorry for the long post...

 

I am surprised to see that there isn't any real discussion (that i could find in the search) about chipping the ECU's in these things. There is a ton of info on the 300zx that I have been reading and using.

 

I recently pulled the ROM off of the board in my 90's ECU and started poking around. The setup is very similar to the 300zx maps, so it is pretty easy to navigate.

 

I have a buddy with a 1990 Maxima, who graciously let me dump his ROM as well. I was able to find the Fuel and Timing maps quickly. I basically took those maps and put them in place in the Pathy ROM and crossed my fingers. Considering that they have the same MAF (confirmed by looking at the VQ Map) I wasn't overly worried.

 

The truck started right up, and it was definitely more responsive. I don't have access to a dyno, but considering the official Nissan specs for the Maxima were almost 10HP extra, I think most of that is in the ROM.

 

I still have a bunch of Terrano buddies from when I lived in Japan, so I called my friend Takuya up. He was kind enough to go and get a JDM 1993 R3M VG30E ECU at a junkyard (for about $50) and dump the ROM. He emailed me the .bin file. Aside from the fuel and timing maps, everything is the same in the ROM. The fuel and timing are quite different though.

 

I put that .bin into my ECU and fired up the truck. It seems to have a ton more power. I have a route setup to test my truck when I do any major maintenance (it has nice inclines long straight stretches). There is one incline where the truck *always* shifts down to maintain the speed limit, but it didn't have to this time.

 

I haven't done any real testing yet as far as fuel mileage or as mentioned a dyno, so take this all with a grain of salt.

 

Is there anyone on this board that has messed around with their Pathy's ECU? Is there anyone in the Central Washington area that would like to participate in some experiments with this?

 

Indigent.

 

dude! im in yakima, and am running an '85 z31 ECU, been wanting to get a pocket romulator to re-map with. i'll be your guinea pig.... seems like the stock map for the z31 is set-up for top end and not mid range.

 

also auto metrics in yakima has a chassis dyno

Edited by bitemedoughboy.com
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NICE! Another yakamanian with some tuning guts! Lets get together this weekend. This is definitely all VG30E stuff though. I imagine the timing and fuel maps would be drastically different between the I and the E. Should still be fun to play with though.

Edited by Indigent
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NICE! Another yakamanian with some tuning guts! Lets get together this weekend. This is definitely all VG30E stuff though. I imagine the timing and fuel maps would be drastically different between the I and the E. Should still be fun to play with though.

i have my kids this weekend, but i should be able to hang out for a little. i have a spare ecu that we can use for the test pig. ill look around and see if i can find my solder sucker and a eprom socket. PM me youre #

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i have my kids this weekend, but i should be able to hang out for a little. i have a spare ecu that we can use for the test pig. ill look around and see if i can find my solder sucker and a eprom socket. PM me youre #

 

Whoops, I missed the model year with the "e"

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I definitely want to at least poke around in one of the TBI ROM's. I will call up my buddy in Japan again and see if he can get me an image from one of those as well. Probably not though, because it is pretty rare to come across such an old rig in a junkyard over there.

 

Hey packie88, just let me know. I really want to get some of these different images into a someone else's rig to see if they feel any chage as well. It may just be the placebo effect for all I know.

 

I also want to get a rom image from a Cedric Gloria (JDM). It had a VG30E and had almost 180HP. Again, that will probably be hard to find though.

 

anyone else in WA?

 

indigent.

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the TBI units should be re-mappable as well, Lee (formerly of L&P) used the Pocket Romulator to reprogram his 1988 TBI that was supercharged. i have extra 87 & 88 ecu's if someone needs one

 

 

I'd be interested in being a guineapig with with my VG30i if I had a spare ecu to try it on. Its my daily driver so once I get it fixed I can't go bricking it again without a backup. I know 4x4parts/JWT do this for ecu's but I don't wanna run premium and I've also heard their programs burn a little on the rich side.

If it saves me gas great! if it adds power too even better. If it cost gass but adds power I may let somone else try it.

Edited by MY1PATH
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I'd be interested in being a guineapig with with my VG30i if I had a spare ecu. Its my daily driver so once I get it fixed I can't go bricking it again without a backup.

let me check my inventory of spare parts this weekend and let you know what i have. if i have one i'll sell it cheap.

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Just a reminder, all of the tinkering I have done is with the VG30E. I know nothing about the maps and whatnot from the VG30I. All I have done is take the fuel and timing maps from the maxima with VG30E and the japanese pathy VG30E and put them into my US ecu. But obviously, the maps will be very different, because the fuel delivery system is so different.

 

It is 100% possible to do the same thing to the TBI ecu's, but I don't have any personal experience with them. I would love to play with one just for @!*%s and grins. All of the tuning principles for nissans are the same. Once you learn one rig you can figure others.

 

Bitemedoughboy and I will post up whatever we figure out this weekend.

 

indigent.

Edited by Indigent
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