4 plug distributor....ecu chip

Has anyone ever swapped out for a 4 plug distributor????? I would think t is possible, and if anyone has one they dont want.. or knows of a 4 plug that fits a ca18et.... speak up. And has anyone done anything with there ecu's????

If you want a 4 plugger distributor, hit up one of our UK members. They got the 4 plug ca18et. You'll probably need their ECU too.

Do what to the ECU?

If I didn't need mine, I would have popped it open by now. I have a sneaking suspicion the MKII ca18ets have an EPROM chip.

If you want a 4 plugger distributor, hit up one of our UK members. They got the 4 plug ca18et. You'll probably need their ECU too.

Do what to the ECU?

If I didn't need mine, I would have popped it open by now. I have a sneaking suspicion the MKII ca18ets have an EPROM chip.
We could still pop it open for curiositys sake :twisted:

if I take one more thing apart on this car, I think the whole thing is going to fall apart

you should open it anyway. Take one for the team. It would answer a LOT of questions about what we can and cannot do fir the ecu tuning side of this car.

what exactly is considered a mk2 ecu would 10/85 cover that? if so i'll rip mine apart tonight and look at it

nope ... mk II is 86.5+

the 5 mode ECU

Fine ... I'll just answer my own question ...

Heh, but I'm only taking it apart!

what exactly is considered a mk2 ecu would 10/85 cover that? if so i'll rip mine apart tonight and look at it
10/85 is probably going to be a MKI ECU, but taking it apart wouldn't hurt...clean the dust out that is probably there...8)

If I'm not mistaken the EPROM chip would be removable, so I think that if there is a chips that can come out without de soldering anything it would be considered MKII...is this right??? :dontknow:

and Mr.200, the ECU from Hwy 9 I will probably take apart. It is an 88 so it is guaranteed to be MKII. The guy who was supposed to take the car out of hte pile was off for a few days, so now I can't look at it until next Moday...bastards...atleast they are taking it out of hte pile for me...8)

Heh, but I'm only taking it apart!
You say that now...:twisted:

I will make sure I get the one from the 88 atleast...you know if anything goes wrong (nothing against your ability, but I've seen what the previous owner did to your 200)...8)

If I'm not mistaken the EPROM chip would be removable, so I think that if there is a chips that can come out without de soldering anything it would be considered MKII...is this right??? :dontknow:

Unfortionatly alex if I was a betting man (and I am) I would say you are mistaken. It is very rare that an ECU will ship with a socket (the part that lets the chip be easily removed). Now yes, eproms are wonderful because you can reburn your own program on them, but you still need to socket the board to do so. I seriously doubt that the board would have a socket on it from the factory. It is just uneeded cost. They never need to remove the eprom, they just need to throw different eproms on depending on the model car, etc, etc.

Anyway, socketing a board is not *too* bad. If its your first time, it will take a long time, and depending on the condition of the board sometimes it takes a LONG time, but its all a learning experience.

I caution everyone, even if we find that the mkII ecu's are eprom, we still need to disassemble the code, which will be a pita. Writing new functions into the chip is the very last step of the process, and yes being able to reburn the eprom is a very powerful tool, but even if we find out they are eprom we are definatly not out of the woods yet. Now if we can find similarities in the code between an already cracked chip (CA16DE has been cracked along with the DET correct?) then we will be off to the races. But keep in mind (IIRC) that the det uses coil packs (aka electronic ignition maps) so we will have to ignore a whole lot of code with that.

Bottom line, if you guys really are going to spend that much energy, you might be better off with something like the MegaSquirt. Because of our non-digital ignition, it is a great fit, run any injector we want, speed density and all for a few hundred bucks. Add another $300 for a wideband and you are home free. If you have the know-how its the way to go IMHO.

Off the top of your head do you know how many pins there are in the chip?? This is something I don't know...it is possible I may already have the piece to make it a removable chip if not already...8)

28 pins on the eprom. There is a slight chance that its a 24 pin, but so far I havnt heard of Nissan using those.

I think Alex was thinking that since it would be an eprom that it would be removable. As the good doctor already stated you would need to socket it first. There are ways of doing rom dumps off chips while they are still on the board, But if you are going to tune it and change anything than you need the socket anyway.

As for the tuning part, as was already stated if the chip has the same address files as the DEt or DE engine than we can just hook it up and start playing with fire.

About the ignition thing, the ET engines have electronic ignition that IS controlled by the ecu. So those maps will hold some relivancy for those cars.

I wish somebody would get some guts and crack their ecu already. A LOT of these conversations could be ended quickly if we found out that the ecu doesnt even have an eprom in it.

About the ignition thing, the ET engines have electronic ignition that IS controlled by the ecu. So those maps will hold some relivancy for those cars.
actually I believe that its just the MKII cars, and it is not a coil pack ignition, so I do believe it is just the computer that controls timing advance. The distributor still controls spark for the most part (correct me if I'm wrong).

As far as the same address files as the DE or DET motors, I seriously doubt it. When were the orginal build dates on all 3 motors? If they are close we may have a chance.

The build dates would prove this for sure, But I would bet money on the address map being the same as one of those 2 engines.

And From what I am told is written in the FSM the ecu does actually control the ignition timing on the ET models only. The other ones are vacuum advance. How much control it has I am not sure.

Usually fooling with the fuel maps is enough for a light tune anyway. The ecu will figure the rest out for the proper timing.

MKII CA20's are not vacuum advance...trust me...8).

No I was thinking that I might have enough electronics parts to take it apart, and make the chip a removable one. :twisted:

If I have the time I will tkae mine apart tomorrow, and take pictures at the same time...and the DE would maybe even have a chance in working in the 20E motor...or atleast I hope 8)

Pics of the eprom if there is one is the most importance. Also we need to know the numbers written on the chip itself. It will say something like

27C256
27256
27C128
27128

I suspect it will be one of those 4. Most likely the latter 2. They are actually ht e same chip just a different way of writing it.

Well, the MKIIs and the DEs were made simultaneously and the KA24E in the 89 + 240s ECU looks very similar to the one in my MKII. I'd like to see what ECU is in the ca18det S12s. Are they coil on plug?

I don't think there's too much ECU control to the ignition. IIRC the only time the computer does anything to the timing is through the detonation sensor.

Other than that, the ECU just acts as a translator ... it gets the signal from the CAS, so it would have a fixed lookup table, just like the injectors. Which is all we really need to find.

Z32, R32s, S13s all use the same coding. So if the MKII ecu is really just the first appearance of that generation of ECU/coding ... we're laughing.

Of course, 5th injector setups do work, and don't involve nearly as much research.

I'll crack mine open tonight I guess.

Tonight should be just about over for you now. Any luck on the guts of the ecu?

I pulled mine apart for a look a few months a go spent half a day looking on google for info on all of the chips in there didn't turn up much at all. none of them have windows in the top. Couldn't realy work much out.
it's an '84

the chip prolly wont have a window on the top. It is a program once only type chip. As long as you find one with 28 legs on it and a marking like this

27C256
27256
27c128
27128

then you have what we need

Nah it wasn't any of those eh, cos they all give ya data sheets in no time when ya google them. I couldn't find shit when i tryed. My computers still on the floor so when it stops raining i might pull it out again.