Few 4AGE bigport questions

[Rotor-Warrior]

Hey all, Just picked up my KE and only ever owning nissans and mazdas im a bit of a noob with the toyotas... anyhow

1. my Ke70 is running a bigport 16v 4AGE apparently with an ADM loom and ECU. It feels as if it has a flat spot. I want to check the timing but cant find the diagnostic port in the loom to bridge the terminals. CAn someone post up a photo of what it looks like???

2. I also have a JDM ECU, if i plug this in will it give me any advantage over the ADM one?

3. Have a cold start issue. Ive been told the throttle bodies are meant to have coolant running thru them and that there is a vaccum line in the throttle to help bring up the revs at first start. On mine there are what looks like coolant lines blocked off and loose vac lines everywhere. Could someone also post up a close up few pics of how a stock intake maifold should look . Just wanna know where everything goes so it can run as best as possible.

Many thanks in advance

Isaac

[ke70dave]

hey man, alrighty..

1: i just changed the timing on my bigport and my loom doensnt actually have a diag port, i changed it....and its working fine. so just check it anyway. does anyone know what the diag port bridging actually does?

2: jdm ecu has a much nicer tune, 96kw as opposed to 86kw? you need to run high octane fuel because it advances the timing a fair bit more than a ausi computer. and im told you just plug them straight in. im told you should plug in the speed sensor or the jap ecus run a tad rich. my bigport has a jap ecu and has no speed sensor (yet) and seems to run quite well though.

3: just block everthing off! the setup is to heat up the air coming in, we're talking seriusly cold conditions to need this. mine is all blocked off and runs fine, but it does have a hunting idle...which im not sure if this is attributing to it. i only had the engien goin for a week or so, so ill have to investigate further.

[adam]

The diagnostic port thing is really just a yellow plug with two terminals inside.

This is what they look like on the loom,



There should be a few hanging around in the same area with caps on it. Find the one where there's only two to bridge up.

Without bridging these up, your timing should be about 15 degrees before top dead centre. With it bridge, it should be the 10 degrees.

Bridging this will drop the idle a bit.



With the hoses on the throttle body, just block it all off and you might have to even block up the holes which let the air through. I blocked off all the lines, but my idle was at 3krpms when warm, blocking EVERYTHING off gave a normal (1krpm) idle, but during cold starts, you would most probably have to keep your foot on the throttle.

[Rotor-Warrior]

CHAMPION!!!! thanks heaps dude

KE70DAVE thanks heaps for your reply too

greatly appreciated

[Eircamae86]

It looks different on an 86 loom, it a black box with a few different bridge choices

[Tim.duncan]

(i have only played with a 101 motor and that has a small box and you put a paperclip between te1 and E) But by bridging your terminals with the motor running it will disregard all advace timing comands from the ecu like cold start ect ect. by doing this you set the base timing and then the computer will advance from there as needed.

I was under the impression that the coolant lines went into the TB and there was a wax type sensor that when it melted the cold start would shut. SO if you block off the piping really your car is in cold start mode (tb bypassing more air) the whole time?

hope this helps

[sundee]

The diag port on the 86 or jdm big port is on the passenger side hanging near the fire wall. It's a cylendrical case with a red cap, it's the only one in a group of 4 that has 2 pins except the fuel pump test plug but it's rectangular. That's where U will find your diag port on a bigport 16v. If u need a pic I can easily take a snappie for u

[slydar]

it depends what loom you have really, if you dont have a jdm ecu, and your idle control valve isnt hooked up, i would assume you have a converted ae82 loom, and therefore, the diagnostic port could be anywhere, or gone.

you can bridge the terminals at the ecu. i cant tell you which ones though (because i dont know )

as for the iddle control.

how it works, is it is a valve, controlled by coolant temp. when the coolant temp is cold, it opens the valve letting air through. as the water heaps, the valve closes.

the jdm ecu you can just plug in. all pin outs are the same. and you should do it. dont worry about the speed sensor. not an issue and the speed sensor is in the speedo head in an ae86.. seeing as your motor is in a ke70.. well you cant hook it up anyway

[adam]

Yeah it'll let air go by all the time, mine idled at ~3krpms once warmed up completely. You'll need to block the holes which let all the air go past in the throttle body. I just used liquid weld and filled the hole up, sounds a bit dodgy, but it does the job and hasn't caused any problems so far.


And with the diagnostic port thing, I've noticed that it's either the black box with 'diagnostic' written on it or the yellow plugs, both do the same thing it just depends on what loom you've got.

[pandatureno86]

THere are early model and late model loom for AE86
black box ones are the late model
whereas the yellow ones are the early model