Diagnostic Results

Results friend 4 

4A-G 20v AFM original then later change to 20v MAP wiring loom, 4 throttles and ECU, hence running on MAP :) yippy

HYBIRD silvertop + blacktop

December 2003

No error code. No problem with transplant.

Initial driving very light, very strong, very willing, but a bit dull at take off. Overall power output also a bit strange from the perfectionist point of view :) heheh

Injector Pulse Width 2.4 ms  
Ignition Advance 9 CA  
ISC duty 33 %  
Engine Speed 1300 rpm  
Air Flow 1.31 v  
Coolant temperature 90 c  
Throttle Position 0 %  
Vehicle Speed 0 kmh  
Target A/F Left 0 v  
A/F Feedback Left OFF    
Knock Feedback OFF    
Starter Signal OFF    
Idle  ON    
A/C Signal OFF    
O2 feedback LEAN    

TPS 0% and IDLE ON is dull and slow / reluctant to change to OFF, so it is messed but extremely difficult to match.

At the end just listen to the engine sound. Strangely the 20v AFM type engine does not have such distinct IDLE ON and OFF sound. So the TPS is knocked forward and slowly backward until the engine sound reduces tone. That area is also calibrated with the diagnosis reader as very close to TPS 0% and IDLE ON position.

It is unknown why the idling rpm is so high at around 1,300. Later when checking the distributor timing using the timing light gun then found that it is knocked to 17 degrees. This is way beyond original specifications.

It is then knocked to 10 degrees and the idling rpm immediately reduce to 1,050 which is much better than before.

Test drive - not much different, will need to ask owner later.

If the idling rpm is to further reduce to original specifications, which is 880 +/- 50 then the 4 throttles' vacuum syncronisation will need to be adjusted. Please see 4AG-E 20Valve Engine Repair Manual page FI-46.

If I remember correctly, all 4 throttles' vacuum will need to be locked-down. This is done by turning the screws clock-wise. Best turn 1/8 rounds on each throttle then wait no less than 1 minute to observe the engine's behaviour. As said earlier, Toyota's 20v are stupid :) hahahhha


  1. Diagnosis System
  2. Diagnostic by DCN Pro
  3. Diagnostic for a friend
  4. Different Diagnosis
  5. Results 1
  6. Results 2
  7. Results 3
  8. Results 4
  9. References



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