Retarded timing

[Jimnist]

Hey everyone,

Lately, it seems as though my engine isn't running as smooth as it should/used to. I checked the timing today with a timing light, jumped T and E1 and it was reading 10* BTDC and around 16-18* BTDC without the jumper. This falls into the correct specifications of my manual, but here's the strange thing. When i rev the engine for the first 0-1 second, it retards...a LOT; past 0*. But thereafter, advances like it should. I think this is what's causing it to run the way it is.

What would cause it do this? Has to be something controlling the electronic timing advance, right? Is it the big electrical thing under the distributor or could it be the ignition module?

Any help is appreciated

[Jimnist]

Bump?

Are there any vacuum hoses that can control or affect ignition timing? Or is it all electronic?

[fredk]

its all electronic, look up tccs on google

[Jimnist]

Did a quick google search and fond TCCS stands for Toyota Computer Control System. So you're saying it's the ECM that's causing the problem? I'll don't think i'm getting any codes as i'm not getting any CEL's, but i'll jumper T and E1 just to make sure.

[fredk]

pull the timing up till it just starts to ping on slight acell, try it for a few days

[Jimnist]

Originally Posted by fredk

pull the timing up till it just starts to ping on slight acell, try it for a few days

How would that help the initial retarding when i rev it? It's advanced at idle and advances a second or two after i rev it. Just that initial movement of the throttle causes it to retard.

[white90dx]

Originally Posted by Jimnist

How would that help the initial retarding when i rev it? It's advanced at idle and advances a second or two after i rev it. Just that initial movement of the throttle causes it to retard.

Its supposed to do that - that's how the computer is programmed.

-Charlie