4g63 head swap question

[sabzi5858]

750cc injectors may or may no work for you. every car has its differences and there are just too many variables to determine that. the ecu i had may also have been part of the cause because of the timing it was trying to push. ultimately, how much air you will be pushing will determine what sized injectors you should get. if you can't tune them with what you have, that means you need to upgrade to a better tuning system.

i'm not familiar with the scanner you mention, but if it works, it works lol. a datalogger's convenience is that it can run on a laptop pc, or a palm pc. the datalogger at digitaltuning.com is meant to run from a palm. it is very small, and convenient to move around.

eprom ecus are indeed more expensive than non-eproms most of the time. i paid $170 for mine. with 2gs, almost all '95 ecus are eprom, and no other year is eprom, but with 1gs, it's pretty much random.

the trick with the fusebox is to not get rid of your stock harness completely, but instead, open it up, and cut out all of the unnecessary wiring, and leave the wiring going to the fusebox. almost everything from the fusebox goes to connectors other than the ecu anyways.

one thing to note with the 1g ecu that i mentioned, is i'm not sure if you can make your speedometer work with it. it may need intervention from the ecu. it's not likely, but it's possible. (saying this so you don't blame me if the speedo doesn't work, and because i never hooked up the speedo in my car when i had the 1g ecu)

like jip said, the wrong version of the knock sensor won't work, it has to match.

from what i know, all 7gs should be 7-bolt. i'm not sure if they ever went to 7-bolt with the 6gs though. and i can't confirm either of these. may i ask why though?

i used a 1990 ecu, the main difference is two wires were swapped from '90 to past '90. so if either the ecu or harness is '90, and the other is not, you'll have to swap two pins. (look at the 1g pinout on vfaq.com to see which ones). i'm not sure if the 1g fwds had a speed limiter ( i don't remember) i had an awd ecu so no limiter for me.

i'm not sure how much hp i'm pushing, but according to dsmlink, on a crappy tune running rich as hell, it said aroun 280whp around 4000ish rpm. i'm currently having problems with the log cutting out, so it doesn't really display properly, so the numbers may be way off (actually it said around 350whp around 5000ish rpm, but i think that was skewed). on top of that i'm not sure how accurate the dsmlink hp calculator is. once i have the logging issues solved, i will get it tuned nice and dyno it to get some real numbers.

i'm not on the 4g64 anymore, i'm using a 4g63T with stock rods and pistons. i plan on going back to the 4g64 but probably built by magnus with ross 8.5:1 or maybe 9:1 pistons and pauter rods. i wouldn't mind crower rods either, but magnus uses pauter, and i trust their choice. they also say they won't use any piston manufacturer other than ross now.

just a quick note, i'll be travelling for the next two days so i won't respond until after that.

[JiP]

Damn Sabzi where do you get your cash from!

Have you ever thought of swapping the 7g speedo guage with the speedo from a 1g? We all had problems with our tach not working after the 2g swap which I attributed to the fact that its calibrated to work with a distributer single pulse output and needed a tach adapter. I was researching around and found that the early 1g coil packs 89-90 had a tach adapter box on the bottom, I picked up a set removed just the tach adapter and installed it in my setup and boom stock tach worked great.

The speedo does indeed grab the signal right from the speed sensor itself though,( in both galant and eclipse), so you shouldnt really be having any problems.

[StreetDreams]

I asked about the 7bolt thing because I was thinking of getting a 6bolt to make life easier when putting pistons and rods in. I have the 7 bolt block already and probably will use it; I just wanted to know the years because if I came across a 6 bolt block for cheap I would get it.

When you say 'speed limiter', do you mean rev limiter? Or are there dsm ecus that actually limit the speed of the car? I didn't think that was something that pre 95 cars had...but then again I'm not a mechanic. What is the rev limiter set to on the 1g ecus?

Thanks for the info about the two wires having to be swapped. If you have any other tid bits of information that would be useful, pass it on.

Thanks for all your help with this,

Mike

Who cares if the speedo doesn't work...I never do the speed limit anyway!!! :thumbsup:

[sabzi5858]

JIP, you have to tell me more about how you got the stock tach working. i have a '90 coil pack, and indeed it has a tach adapter on it, what did you do to get your gauge working?

when i say speed limiter, i mean it limits the top speed. like i said, i don't know if it applies to 1gs, but 2g fwds have a speed limiter. stock rev limit should be right around 7500rpm.

as JIP mentioned, the speedo should work, but i'm not making any promises simply because no one who tried it told me it worked, and i didn't try it myself.

[StreetDreams]

Sabzi, I sent you a pm but I keep getting an error message...let me know if you get it or not...

[JiP]

I dont remember the wire colors but just look how its hooked up on the coils now. 2 wires go one to each coil pack trigger line, and the third wire is the tach signal output. The tach signal that comes out of the power transistor I clipped and wired the tach adapter output to the line so the entire car sees that tach signal and doesn use the power transistors output. I had no change in driving etc.. If you want to keep the power transistor tach signal feeding your ecu, then you have to crawl under the dash on the drivers side footwell is the connector for the guages you gotta find the dash tach signal line, cut it, and run the wire from the guage to the tach adapter.

[JiP]

Two wires on the adapter go one each to the trigger lines on the coil, the third wire is the signal output tie that to your tach signal wire in the car and clip off the power transistors tach signal wire or they will interfere with each other since they are on the same line.

If you want to keep the power transistor tach feeind your ecu and just use the adapter for ur guage itself then you have to run the adapter output directly to the tach guage signal wire which is in the drivers side footwell i duno exactly what colors etc for ur year car.

[sabzi5858]

so after you did this, your stock tach shows the correct rpms, and your s-afc also does while being set for 2 cylinders?

[JiP]

so after you did this, your stock tach shows the correct rpms, and your s-afc also does while being set for 2 cylinders?

Um my safc2 is set to 4 cyl. But I also keep my afc on the crank signal line not the tach. The stock tach showed about the same reading as the afc and logger. My tach i think slips a lil, if I pop open the guage cluster and set the needle exact rpm the afc or logger reads after a couple months it becomes ~50-100 rpm off, it was like that even when I was sohc stock ecu. I think I took the needle off so many times that it doesnt grip as well anymore..i dont care to fix it ~100 rpm different dont make a difference to me and I can always just glance at the afc.

[sabzi5858]

well, that's strange. i know i had to set my s-afc to 2 cylinders to work with the '90 wiring (as said by RRE: RPM Signal off by half (1G) Because of the way that Mitsubishi triggers the ignition coils, this is normal. To fix it, just set the Cylinders to "2" )

well, if the crank signal works for the s-afc, maybe i could just use that signal instead?

[JiP]

<div class='quotetop'>QUOTE(sabzi5858)</div><div class='quotemain'>well, that's strange. Â*i know i had to set my s-afc to 2 cylinders to work with the '90 wiring (as said by RRE: RPM Signal off by half (1G) Â*Because of the way that Mitsubishi triggers the ignition coils, this is normal. To fix it, just set the Cylinders to "2" )

well, if the crank signal works for the s-afc, maybe i could just use that signal instead?</div>

maybe that was just a 1g thing? If I think back it will make sense to me but off the top of my head I dont rmemeber the details of the ignition system. All I know is my safc is on the crank line and its set to 4 cyl. And it works and reads almost the same as my logger.