how to set 4age timing + idle issues *HOW TO* update

[gmacrae]

I've searched for this but haven't come up with an accurate answer.

I've got a ae92 fxgt, bigport redtop, the idle is set to about 800rpm when warm, but when i start it cold it idles at about 2300rpm and slowly drops when it warms up. I understand there's the wax thing in the throttle that melts and lowers the idle when it's warm. Can i just remove the coolant plumbing from the throttle so it never melts the wax and set the idle right down with the idle screw?

Or is there another way i can sort the goofey cold start idle?

Also, once the idle is properly set, i want to set the timing right to take anvantage of bp98. Can someone please tell me which pins i'm supposed to short in the ecu plug and the correct procedure. How bany degrees bdtc? I do have a timing light btw.

Cheers for any help

Gene

[Pelo]

To set your timing short the T and E1 pins. Standard timing is 10 degrees BTDC@800rpm. Then you remove the short and the timing should be more than 12 degrees if auto or more than 16 degrees if manual.
^^^That is fact^^^ for a bluetop anyway
Now for the guessing
Apparently the waxstat gets old and crusty and stops working properly. My old rolla had the same problem as yours, also tended to hunt when almost warm, the revs going up down up down. Replace the waxstat I guess.
For 98 maybe advance the timing 1-2 degrees at a time and see how she goes

[KinLoud]

Make sure that the throttle is fully closed when you set the timing with the jumper in.
If the computer sees that the throttle is a tiny bit open it is impossible to set the timing properly.
Idle. If you want to block off the cold idle setup... get a foam earplug and stick it in the cold idle bypass air hole. Didi this on my racecar with bluetop 4age work fine.
If you set the idle by adjusting the throttle stop screw... the computer will sense the throttle is a bit open and make it impossible to set the timing as above.

Ken
Ham
021 408 863

[gmacrae]

Thanks for the replys guys. So for bp98 12 degrees (maybe more) should be fine. Has anyone done any experimenting here?

Ken: Thanks for that. I removed the water stuff off the bottom of the throttle and have plugged it up (bolt and epoxy) Am going to get rid of the other idle up bits from the steering and ?Aircon? idle adjustment. Im not going to adjust the little screw on the throttle lever to get the idle right, was just talking about the idle speed screw (throttle bypass bit). Hopefully this will allow enough air thru for a good cold idle with the help of a healthy spark and the 5th injector, if not, i might try enlarging its port (bypass) a bit to give more adjustability.

Has anyone else out there removed this gear to give their 4age a simpler idle control? If so, i'd love to hear about it.

Cheers

Gene

[gmacrae]

OK, i removed all the idle up shit i could find, and the car idles exactly where i want it to, is very easy to adjust idle, doesnt die when i start the aircon (not that i ever do) and cold starts/idles fine.

For anyone else wanting to remove all the idle-up gear, simplify your engine bay and simplify idle adjustment on a 16v 4age:

Remove everything plugged into your throttle body (just unplug TPS, dont remove it). There is a small coolant line to and from the bottom of the throttle, just loop this back to itself on the main coolant hoses below:
(loom is kinda blocking pic a bit - its the line with the white dot):


Remove throttle body, remove the entire idle up section off the bottom of it (4 or 5 phillips bolts). You will need to plug 2 holes from the outside of the throttle now. One is round (about 10mm) and other is a small oval shaped hole (about 15mm X 4mm). You'll be able to see them easy. Make sure you plug these both, properly. I used a bolt and epoxy (araldyte) for the round hole, and shaped a piece of aluminium and epoxy for the other hole. Get/make a new gasket and reinstall your throttle body.

Cap these 2 lines:


Remove the 2 air lines on the steering column and loop them together like the coolant lines you did:


Remove the charcoal cannister (black plastic box by passenger side strut tower). This is bolted to the car at 2 points, and the rear of the bracket shares a bolt hole with and is tack welded to the fuel filter mount, cut thru this so the fuel filter still mounts fine. Take the thick line from the top and feed it back thru the hole where the bottom line went (down to the road). *** Install a small plastic fuel filter in this line that vents to the road - you can get them for only a few bucks *** This makes sure the gas tank still vents safely. There is a solenoid for the charcoal cannister, unplug/remove this solenoid and its lines, the ecu wont care.(sorry dont have a pic).

Remove the shit with all its lines behind the passenger side strutt tower. This stuff appears to be the A/C and econ A/C idle up stuff. Unplug as i have, remove 2 bolts and remove all its lines with it.


By now you have probably removed the single line that goes into the intake just after your pod filter, this is the feed for most of this idle up gear you've removed. Since you've got this hole in your intake now, cut off the 10mm or so of rubber hose sticking out, drill it out with a 10mm bit and shove your intake temp sensor back in here. It'll fit snug. If you're like most people (me) this temp sensor has been floating around your engine bay ever since you got rid of the stock airbox. May as well put it back in the intake line where its supposed to be:


Nice and tidy.

This is what you should've removed:


Now set your warm idle to about 1000rpm, reset your timing, and you're good to go. If your 4age is healthy with a good spark, you didnt need all this shit you've just removed. Turn the aircon on, revs drop about 100rpm but it still keeps idling fine. Cold starts are fine, might require a tiny bit of gas for a couple of seconds, and make sure your 5th injector is plugged in.

Gene

[CozmoNz]

Im fairly sure i remember revhead saying something about "nono" to removing the charcoal cannister...

give it a minute, hell be in to correct me

[gmacrae]

nah, get rid of it, have done on the supra, ran it by a bunch of people and nobody could come up with a decent reason not to

[matt dunn]

nah, get rid of it, have done on the supra, ran it by a bunch of people and nobody could come up with a decent reason not to

except that when you use fuel from the tank you need to let air in via that pipe.

You are now letting air and dirt into your tank.

[gmacrae]

Ahaa! I put a little filter on the supra's tank vent just incase something like that might happen but haven't on the FX. Cheers Matt will do the same there