Marc

I know when setting timing on the 3VZE you have to short the TE1 and E1 Terminals.
I noticed today that when I removed the jumper pin that my strobe indicated that my timing was still at 10 degrees (yes I had it jumpered properly as my check engine light was flashing).

Question is, is this normal?
If so, what's the point of jumping TE1 and E1?

thanks

runethechamp

I posted about this a while ago, and the first thing to check if there's no difference in timing/rpm when removing the short between the terminals is the TPS sensor. I haven't gotten around to checking mine yet though

Marc

Thanks for the info. I found the thread you were referring to.
I guess checking my TPS is in order for me too.

Bumpin' Yota

you short those two jumpers so that the ECU wont add timing if it senses other things turning on. For instance if you turn on your AC it will advance the timing about 5* at idle, etc...

At least thats what I've noticed..

runethechamp

Hm, I have to try that. I always made sure to turn all lights, radio, fan etc off when I did my timing check, so maybe that's why there's no change for me. I do have to check the TPS though.

Marc

Update - Thanks runthechamp you were right on.

I removed my throttle body and installed and adjusted a new to me TPS (thanks to babypig).

Engine now goes into base timing mode with the jumper on.

snap-on

shoot me a link that explanes it or perhaps a simple explantion can sufice but im confused.

on an "oldish" school motor with a distrubuter (3vze) how can the computer adjust timeing?? (or was what i interpret as timeing) which is when the spark plugs fire in relation ot pistion location and or valves open/closed. My poor understanding is the timeing is adjusted by rotating the cams in relateion to the crank (via the belt/chain) or tweekeing the distrubiuter to adjust the reltive location between the cap and rotor. spark duration being controled by the "width" of the rotor (and capciatce of the coil) As neither the above are able to be physcially changed by the computer, how can it affect (what i understand to be) the timming?

To my knolege computer adjusted timming can be acomplished a couple of ways, a bmw(bosch) method of VANOS and/or (non distrubiter) electronic ignition in which a coil sits ontop of each plug and gets the "fire now" voltage from the puter. (most common application at least)

what the computer CAN do (or more the vacume system on a 3vze engine) is adjust idle. In your example the relay closing on the AC compressor also powers a vacume switch to activate an idle bump up pot on the TB. or high power stearing pressures (like toward the end of the PS box) active a vacume switch again activating the same idle bump up. (computer has nothing to do with it)

runethechamp

This is my theory. If the computer adjusts the idle by vacuum or similar, the timing will automatically advance since the engine is going faster. After all, the timing advances with increased rpm for normal driving. When I was fiddling with my truck I noticed that if I adjust the idle with the idle screw, the timing would actually change.

phorensic

Jump TE1 and E1 just makes sure the ECU isn't adjusting timing at all. It's not complicated guys.

miketerrizzi

i just did my timing, runing at 15* safely, the jumpers disable vacum advance, before i adjusted my timing the jumper didnt do much but move the timing by two degs, if you have it jumped ur dash O/D and CE light are blinking, then mess with the timing. once i got a tank full of 93 im gonna hit 17* .

Reason i know this, hanes manual says plug vacum advance or jump the diagnositic jumpers, so it must disable the vacum advance out of the EC.

later.

Bumpin' Yota

Ill have to go digging through my toyota FSM, but im 90% sure that the puter controls the timing advance. Reason being, why even have a knock sensor? And when the knock sensor is bad on a 3vze ever notice how the puter somehow manages to pull power? Thirdly why even jump the connectors then?

ill edit back with what I can dig up...

EDIT:


Ok since Im at work I dont have access to my FSMs however I did do a little searching. If Im not mistaken our ECU controls when the coil's breaker points are opened and thus controls timing in this way.

Toysrme

Yeah, there is no vacuum advance. There are idle-ups for powersteering, and A/C.
The deal is that most Toyota ECU's will jump the ignition timing around to help stabalize a bad idle. If it's having a problem getting the idle where it wants it to be with the IAC/ISC valve (3vz-e's have an ISC), it'll start playing with the timing too.

phorensic

Ah crap. 3vze's have an ISC valve? Now how the heck am I supposed to install Megasquirt and get it to idle?

Are you SURE they have an ISC valve?

Toysrme

Read your FSM. It does have an ISC valve.
MS-II can control an IAC/ISC valve.

phorensic

Yeah, but MSII is just that much harder to get working than a v3.0 PCB MSI with MSnS.