4age, Ignition Timing

[DearmanKE]

Hey guys.

Car model: Te72 T18

Engine type: Bigport 4age, Jap

Problem: ...

Just put my motor back together after blowing headgasket a while ago, its a standard bigport 4age

Ive started it and run it and checked timing and when its set at about 15 it does not want to rev up quickly.
when u open the throttle it hesitates slightly befoire revving up.
I advanced the timing further and it revs beautifully. but the timing at approx 800 rpm is about 35 degrees BTDC.

The cam timing is set right and the harmonic balancer is good(mark is not out)

I do not have a diagnostic plug that im aware of, my loom has been cut and is quite a mess. so i cant bridge any terminals.

but still it seams like the timing is wayy to much, but if i put it lower it hates revving.

can anyone shed some light on this?

[timbo]

Check with the timing gun that when you rev the motor that crank pulley isn't retarding (mark moves clockwise) and that it would advance (move anti-clockwise).

What you have described sounds similar to when a wire in my TPS loom was broken, so on throttle movement then ECU wasn't advancing the timing.

[Matt]

You need to bridge it... At your ECU , splice a switch into the T and E1 terminals and add a switch.

Flick the switch to put you into diag mode and off again to come outta it.

You'll find the ecu terminals under the lid of the ecu / printed on the circuit board or here

[timbo]

Even so, at 15-16 degrees unbridged the motor should rev.

Did you remove the distributor at all? Is so then it may be out.

[DearmanKE]

TIMBO

u may be my saviour

just tryed again and exactly as u have described, when i blip the throttle the timing jumps back from 35 to approx 20 or just under.

can you give me any more info?

[timbo]

I would say it is your TPS. Unplug it and see what happens, a 4AGE should still run with it unplugged, just not as well as it should. It is time consuming but you will need to find which wire is broken or if the TPS itself is stuffed. The 4AGE manual in the tech documents section outlines all the checks you need to do with a multimeter.

edit: On idle when you remove the TPS the car should start to idle higher, if it doesn't then I would say it has to be your TPS.

[DearmanKE]

I did the multimeter checks and the Ecu is receiving the right signals from the tps. So maybeim looking in the wrong place

[slide86]

are you sure the dizzy is refitted correctly? sounds like its out by a tooth......

[DearmanKE]

Removed it while running and it ran a oil different, slight change in idle and seams to rev a oil quicker with it connected so maybe it's not tps. Maybe an Ecu fault?

[DearmanKE]

Ok dizzy may be out, correct me if I am wrong but if it's out why does it matter as u can adjust it around itself.