b_rippel

I have a 91 P/U 3.0 V6, and was wandering the forums when I saw a post that said if you adjust the ignition timing from 10 degrees (stock) to 12 degrees BTDC, it can result in better fuel economy, power, etc. Anyway, after having this truck for a year and never being very satisfied with the engine I was curious to see what effect this would have on my engine. So after hooking up the timing light, letting the engine idle, I could not see the marker on the timing scale. As it turns out, the mark was off the charts. it was at a whopping 35 degrees BTDC!
To be honest, this was sort of a relief for me because I thought that there may be some hope of getting more power out of it when I adjust it down to 12 degrees.
I must say it instantly sounded much better. idle dropped form about 1300 to 700 (which I read was stock) I havent gotten to do any extensive driving in it yet but it really shocked me that the timing was off by SO MUCH.

Does anyone know why the timing would be set so far off stock? or if driving it for a year or more with it like that would cause any damage to the engine?

MudHippy

I have mine set at ~23-24° BTDC, because it runs better like that IMO. You won't likely get more power from retarding the timing to 12°. If anything quite the opposite.

If the engine wasn't knocking/pinging excessively with that much initial timing advance, then it didn't hurt anything.

FYI, stock idle speed is 800 ± 50 rpm.

91_TOYOTA_4x4

Ummm 34 degrees... Wow lol and it ran? Could have been somebody messing with it without te1 an e1 jumped or a timing light and just messed with it. I run mine at 12 degrees and it DID make a difference 100%. you can go more as long as it doesnt ping so play with it a bit. 34 though isnt going to run to well lol

TNRabbit

You DID jumper TE1 & E1 when you checked the timing, right??

b_rippel

hmm... dont believe so. sounds like i fudged up

b_rippel

So I jumped the TE1 and E1 terminals today, hooked up the timing light and warmed up my engine. check engine light was flashing, im guessing from the jumped terminals.
After the engine was warm, the timing was still at 12 degrees which is where i left it after doing it a week ago without jumping the terminals. anyway, I decided I wanted to advance the timing a little since I wasnt happy with it at 12, so i put it up to 20 degrees, took off the timing light an jumper wires, gave it a test drive and I think it runs perfectly now. Im really not sure what the jumper wire does or what happens if you dont use it. I have now adjusted my timing with and without it jumped and did not see any difference except that the check engine light flashed with it jumped. And yes, I did check continuity with the jumper wires.
Any info on why the jumper is needed would be helpful. thanks

MudHippy

Some 3VZ-Es it doesn't matter whether you do or don't. Like mine, yours, and several many others I've seen mention it here. To the point that it's hard for me to believe that it makes any difference on ANY 3VZ-Es.

Though there are a few here that claim it MUST be a cause for concern, because on their 3VZ-E it does matter. But I'm not one of them. In fact I quit jumping the check connectors to set my ignition timing a long time ago, after realizing it made ABSOLUTELY no difference whatsoever! And there ain't A DAMN thing wrong with my engine!

brianh699

Jumping terminals cancels any ignition advance from ecu.

b_rippel

Is there any signs to know for sure that it is canceling it from the ECU? Or like MudHippy was saying, do some models not need to be jumped?

MudHippy

It's supposed to retard the timing from 10° to 8° BTDC when the jumper wire is removed. Other than that, no. There's no other way to know what it's doing with the ignition timing when the check connectors are jumped/not jumped.

No, the idle speed doesn't change. It's not stated anywhere that it should be any higher or lower, with or without the check connectors jumped.

b_rippel

Welp, I didnt notice the timing retard any and I am happy with how my truck is running so ill jump the terminals if I ever do it again to be safe.

Thanks for all the info everyone!

Huckm80

Thought I would post this here instead a starting a new thread...

I too have been playing around with different timing settings to see what gives me the best power, mainly. I was at 10 btdc and advanced it to 15-18 and my truck ran a hell of a lot better. At 10 btdc it runs pretty bad. Advancing the timing really woke the 3vze up, granted I have a dead or almost dead cylinder....nevertheless I was adjusting the timing, advancing it by ear to try to get the engine to knock or ping and then back off but it seems like I couldn't get it to ping. I advanced it all the way ~30 btdc.

My questions is: Can you hear or feel the motor ping or does the knock sensor catch it before you can hear it? I just don't know if my motor is pinging. I remember putting 87 octane gas in a v6 VW once and it definitely pinged. You could really feel the motor bucking and this was like a '99 model. What gives?

Huckm80

Anyone? ^^^^^^^ Does your motor obviously ping when advancing timing all the way at idle?

Marc

Don't know about the 3VZE but other engines (without knock sensors) I've worked on never pinged at idle but only under load if too far advanced.

Even a slight load sometimes if the timing was too far advanced.

Huckm80

Anyone else want to chime in with there 3vze ignition timing expertise?

Mr. Magoo

My 3vze is currently sitting at 16 BTDC and the only problem that I am experiencing is pinging at highways speeds while going up hills. I have a timing light, so I will be dropping it down to 14 BTDC and seeing what happens. A lot of this is just tune and test, tune and test. Every Yota is different, every driver is different.

toiyodah4WD

Are you using 93 octane? If not you should.

Mr. Magoo

I am. But I am starting to think that the gas stations around me have some poor quality 92 octane. Went to a different station and so far the pinging has disappeared. But... it likes to ping on warm/hot days so we shall see when it warms up.

Don Hawks

my timing was off the chart too. on a 92, i set it to 10 BTDC and it would barely take off from a stop. so it went back to where it was. it doesnt ping. i cant believe how doggy and slow reving it was.

Cmderthick

Starting, with AFM equiped models air fuel ratio can be determined by this meter specifically this meter changes the fuel ratio. In an ignition timing standpoint, my 3.0 was set to a base timing of 25 degrees from a stock 10 degrees.Where this meter was set to compansate this advance a richer mixture was selected by releasing spring tension on this meter indicating to the ECU a needed increased in fuel where the throttle body still controls overall airflow. I found actually retarding it back caused an overly rich mixture hurting performance, this is because the air flow meter spring tension was relieved down to allow for a richer air fuel.I have also installed a aftermarket intake resulting in an increase in air flow. The goal is to reduce combustion temperatures while not sacrificing power this is especially hard dealing with the cross over exhaust of the 3.0, hence blown head gaskets.to avoid these temperatures an increase in fuel is used in conjunction with an advance in timing to boost the motors performance will still burning all the fuel. I have also thought increasing fuel pressure, and or running a heavier oil to boost compression also play factors into achieving peak power from a stock motor. EGRs don't help with intake air temperature either. Fuel cools, you must completely burn the mixture to create maximum pressure at the right time "ignition timing" to either avoid a ping from precombustion or timing to retarded or air fuel to lean. Start with timing then air fuel ratio may even be smartest to buy a afs to determine.