The AUSubaru.com.au Forums

do all you people with EA82 turbo and /or mpfi hear engine knock before it is eliminated by the knock box ? I have often heard cars in traffic knockin' away then it stops. Is this how knock sesnors work in reality? Have only just driven mine a short way and hear knock first then goes away- or i am at the end of runway

What your describing sounds more like lifter noise to me (or tappets in other non-boxer engines). In terms of the Subaru its an oil lubrication issues not a knock senor one.

Definitely ignition detonation

jono wrote:do all you people with EA82 turbo and /or mpfi hear engine knock before it is eliminated by the knock box ? Is this how knock sesnors work in reality?

Yep thats exactly how it works.

The instant the knock sensor detects knock, the ignition is retarded by say 5deg then gradually advanced one deg at at time until knock is detected again. Its a never ending process of retarding and advancing.
In 3plug turbos, the seperate knock box delays the signal from the hall effect sensor to the coil much like a guitar effects pedal adds delay to music.
In 4plug turbos, the ignition is controlled by an ignition map inside the ecu, when knock is detected, the ecu simply subtract and then add to the map.

silly option, but can you add a knock sensor to the 4plug NA ecu? from what i can gather, the knock sensor on the turbo ecu is pin 36, is that pin in use on the 4plug? just thinking of using NA ecu's safely with a turbo engine and throwing around ideas...

I dont think the NA ecu has the feature built into either the hardware or the software of the ecu.

As far as I know the ECU is the same, isn't there a 'turbo/non turbo' wire, that if grounded tells the ECU it is say, 'turbo' (can't remember which way round it is) or sheilded for 'non turbo'?

Surely if you run a 3 plug ECU's knock control system (3 plug dizzy, its module, the knock sensor and the individual knock control box) as a not-connected -to- the -four -plug -ecu . My suggestion was that you do it as a stand alone ignition system and bypass the 4 plug ECU as in not connecting any ignition control to it in hook up, it should all work just let 4 plug ecu control fuel (I might have forgotten to use stand alone wording to help )

PIN numbers are not the same between 4 plug and 3 plug ECU's as far as I have gathered.Have you got a pin chart for your 4 plug ecu yet?

interesting about it being 1 ecu (and that's way cool). i have found a pinout for a 4 plug turbo. can only assume it's accurate. would be great to compare it to a 4 plug non-turbo...

1. check connector
2. air flow meter signal
3. purge control solenoid
4. neutral switch
5. air flow meter ground
6. fuel pump relay
7. crank angle sensor power
8. crank angle sensor reference
9. water temp sensor
10. ground
11. ---
12. air flow meter power
13. duty solenoid (waste gate control)
14. inhibitor switch
15. inhibitor switch
16. throttle sensor ground
17. crank angle sensor position
18. ---
19. ignition switch signal
20. ground
21. throttle sensor power supply
22. throttle sensor signal
23. air conditioner signal
24. starter signal
25. idle switch signal
26. ---
27. control unit power input
28. identification of specifications
29. car speed sensor
30. identification of AT
31. ---
32. test mode connector
33. read-memory connector
34. ---
35. control unit power input
36. knock sensor
37. ignition output power transistor
38. air flow meter burn-off output
39. self-shutoff output
40. ECS lamp output
41. EGR solenoid
42. kick down relay (3AT)
43. ignition output power transistor
44. check connector
45. check connector
46. check connector
47. check connector
48. O2 sensor
49. fuel injector 1
50. fuel injector 2
51. fuel injector 3
52. fuel injector 4
53. ---
54. ---
55. fuel pump control
56. ground
57. ground
58. ---
59. A/C cut relay (3AT)
60. ground
61. ground
62. power input
63. ---

or speaking as someone with no experience in altering ECU use, does the 4 plugger rely on signals from ignition for correct fuelling? Doubting it, orr theres that crank sensor inside is there not ? I guess if you were to experiment by.... If you find unplug just one correct plug of four plugger ecu is disabling dizzy then try instal 3 plug dizzy, its module and knock sensor, see if you can get it all to run.

this weekend i'm going to pull my NA 4 plugger out and see what pins arent connected or are blank. might fill in some questions...

AUSTRALIA TURBO EA82T 3 plug PIN

7 jumper wire for test
45 ECS lamp
22 car speed sensor
44 line end cord outpu
2 airflow meter air intake temp
16 airflow meter (Us) not US America
15 airflow meter (UFIX)
11 airflow meter (UB)
6 airflow meter (ground)
4 O2 sensor shielded
21 ignition pulse
13 pressure switch turbo
vacuum non turbo
33 pressure switch
42 FICCD
37 injector #1
38 injector #2
41 injector #3
46 injector #4
31 AT/MT discrmination
28 AC compressor switch
8 throttle switch ID
10 throttle switch (full)
23 egr solenoid
5 ground for control
3 water temp sensor
32 turbo/ non turbo discrimination
17 clutch switch
12 accelerator switch
50 fuel pump current control shielded
39 fuel pump , egr relay
40 ign power supply
9 starter signal
43 driving ground
47 driving ground
48 driving ground
49 driving grounded shielded


The non turbo 3 plug ECU is much the same except 21 as Turbo the NA is 19 no number 21. 17 and 12 is only on Turbo ECU not on NA

Just posting three plug ECU as something to ponder, considering twilight filled in 4 plug ecu pin listing

one plug
21,22,23,24,25,26,27,28
29,30,31,32,33,34,35,36

next plug
01,02,03,04,05,06,07,08,09,10
11,12,13,14,15,16,17,18,19,20

third plug
37,38----39,40
41,42,43,44,45
46,47,48,49,50,51


I have plug 3 disconnected - running on dedicated LPG, so that is why ECS light not work !! No fast idle control C device
actually, listed backwards, but I am tired and can hardly spell it

Yeah on 3 plug ECU's, there was a wire to designate Turbo/Non Turbo

4 plug ECU's were a whole different story. This is because their fuel maps are much more complicated and they now had ignition maps as well. Ive opened them up and compared them, the boards are completely different.

Funnily enough on my 86 3 plug RX L that discrimination wire ends at one of the engine/body loom connectors under the air box .
Our Aus spec "3 pluggers" differ in the factory WSM , we got the 02 probe where OS ones got an exhaust temp sensor .

I'm not entirely sure what the go pedal micro switch does , I know the 4 plug ones don't have that .

A .

I'm not entirely sure what the go pedal micro switch does , I know the 4 plug ones don't have that .

I was always led to believe it tells the computer to go "full rich" when the pedal is to the metal.

Cheers
Grant

Accelerator switch? Huh? On manuals as well? I thought it was just a kickdown switch on my auto. I removed it when I did the pedal box swap. Although my LPG system did not ned it, I did swap back to petrol for a while and it went OK, had some idle issues , cold start issues due to FICCD disconected and injectors may have gummed up a bit but gave no other drivability issues as I recall.

Might help if someone with 4 plug FSM can help sort pin outs to plug groups

I think Ex temp sensor only lit up a red dash light as you can see at the back of the cluster of reds EX TEMP. Woulda been nice to get both. We must have had some demanding authority that wanted something different to what the rest of the world wanted.

Seeing that crank angle sensor, thinking my idea not going to work if injectors need crank angle to fire correctly, swapping in 3 plug turbo dizzy eliminates your crank angle....BUGGER. Don't wanna waste your time there.....

4 plug ecu, 89 rx, ...we in the US got a "westgate control" on the factory schematics and in the fsm index etc..

that might have been wastegate control but got lost in translation from Japanese to US English. Have you got an electronic connection at your turbo wastegate?
Mark, wanna list up your ECU from your manuals to compliment the others up in here. I had to enter as a cut and paste from wordpad to avoid getting timed out.