assorted EJ ECU questions

[GOD]

Been playing with several different EJs lately, and got to wondering about a few things:

-what does an EJ22 computer use the cam position signal for? And why only on one cam? EJ18 doesn't have one, despite being newer.

-Do they dump in more fuel when they're running hot? Early and very unscientific testing of my EJ22 long motor/inadequate radiator/EJ18 electrics setup showed it to be very thirsty.

-What does the single wire to the power steering pump do? Just idle up when the pump is loaded?

-There are two little fittings under the front of the block, behind the crank pulley - could they be takeoffs for an oil cooler?

-silly question that I could probably work out myself if I looked: how do early EJ22s control idle speed? Looking into an EJ18 throttle body there's a hole above the butterfly, and there's (what I assume to be) an IACV screwed to the top of the throttle body, which the EJ22 lacks.

-is there any info out there on flow capabilities of different inlet manifolds? 1991-92 EJ22 is visually quite different to 1996 EJ18, but I didn't get time to measure anything.

Just curious, and I don't have any of these engines in front of me to tinker with atm.

Dane.

One more thing - I'm running a 1991 EJ22 long motor with the manifold, harness and ECU from a 1996 EJ18. Any thoughts on what the best injectors would be? Currently have EJ22 injectors in there, but it's thirsty, as described above.

[Gannon]

-what does an EJ22 computer use the cam position signal for? And why only on one cam? EJ18 doesn't have one, despite being newer.

Its for telling the ecu when to fire the spark. Your EJ18 must have one, maybe its mounted in a different place.

-Do they dump in more fuel when they're running hot? Early and very unscientific testing of my EJ22 long motor/inadequate radiator/EJ18 electrics setup showed it to be very thirsty.

Makes sense to, but i havent heard of it before

-What does the single wire to the power steering pump do? Just idle up when the pump is loaded?

Yep

-how do early EJ22s control idle speed? Looking into an EJ18 throttle body there's a hole above the butterfly, and there's (what I assume to be) an IACV screwed to the top of the throttle body, which the EJ22 lacks.

EJ22's have a IACV like you described on the EJ18, maybe it just a different shape

- I'm running a 1991 EJ22 long motor with the manifold, harness and ECU from a 1996 EJ18. Any thoughts on what the best injectors would be? Currently have EJ22 injectors in there, but it's thirsty, as described above.

Although it may work out to be close (substituting EJ18 injectors for EJ22 injectors for use on a 2.2L block) it could still be way off.

If you are having fuel consumption issues, have you checked your o2 sensor?

[GOD]

Its for telling the ecu when to fire the spark. Your EJ18 must have one, maybe its mounted in a different place.

Of course. I didn't think that through . But the 18 definitely just has a rubber bung where the 22 has that sensor. I will look elsewhere.

If you are having fuel consumption issues, have you checked your o2 sensor?

Yep, that's on the very long list for my next days off.

Thanks for the answers.

Dane.

[GOD]

Wait, no, that can't be right. Even if there was a cam angle sensor on the EJ18, I didn't transfer it to the EJ22, and the sensor that was in the EJ22 is not connected, so it is now running without one. So it must be firing on both upward strokes, just based on the crank angle signal.

[SUBYDAZZ]

what does an EJ22 computer use the cam position signal for? And why only on one cam?

It only needs one because they are both driven by the timing belt - the cams can't move independently, unless the belt is broken, in which case you will probably know.

[mattl200]

ej22 needs the cam sensor for the injection not the spark
ej18 defenatly dosent have one

the only answer i have for this is ej18 muswt be batch injection which explanes why uses more fuel

[GOD]

Another question: anyone know about differences between timing belt crank pulleys? The one that came off my EJ18 had a different number of tabs around the outside to that off the EJ22.

I'm sticking with an EJ18 ECU and harness - reckon I can use the pulley off a 22?

Dane.

[discopotato03]

You must have a reason for not running the EJ22 computer and loom , can't see why if you have access to both .

For sequential fuel injection you have to have a reference pulse or signal to tell the computer when no 1 piston is rising on its compression stroke . If you start an engine and have no reference pulse then the computer can't sequentially fire the injectors because it hasn't a clue which power stroke is which .
The reason why it is a "cam angle" sensor is because camshafts turn at half crankshaft speed so if it's sensor sends a pulse signal to the computer when no 1 is towards top dead center on its compression stroke the computer knowing the firing order (1/3/2/4) can reference everything from there .

The EJ22's computer will have fuel and ignition maps to suit not surprisingly an EJ22 with a std AFM and injectors .
The EJ18 computer is mapped to suit an EJ18 so it won't work as well on an EJ22 . Things like volumetric efficiency will be different so if the foreign computer is getting signals it isn't expecting to then it could do strange things .

Your call , A .

[GOD]

Last year I installed an EJ18 with matching ECU and harness. A few months ago that engine blew up, and all I could get to replace it was an EJ22. In a hurry to get it going again, I dropped in the 2.2 long motor and plugged it into the 1.8 electrics already in the car. Used 2.2 injectors, 1.8 manifold, all the timing pulleys etc off the 1.8 and all the sensors off the 1.8, with no cam sensor and no ECU control of EGR.

The combination runs alright and feels like it has plenty of power, but it won't idle well (I suspect the 1.8 idle controller doesn't flow enough for the bigger displacement engine), and uses lots of fuel (suss oxygen sensor and mismatched ECU/injectors as well as wrong fuel/ignition maps).

I did have an EJ22 harness and ECU, but they disappeared in the post, and I don't fancy paying to replace them. I will experiment with different manifolds, injectors and sensors I have lying around to try and get it running better.

But that fine-tuning has now gone to the back burner, as it turns out that 2.2 has stuffed heads (serious overheating), so I'm working on reconditioning and putting together yet another 2.2.

The current question is whether a 2.2 crank pulley I have spare will work with a 1.8 crank sensor, as I'm hoping to use parts I already have, without buying more or pulling off anything that is currently in use in the car.

Or the other option is to set the fuggen thing on fire and dust off the bike instead.

Dane.

[phillatdarwin]

if u put ej 18 ecu in a ej22, if u work out what the different % on the fuel rate is u just have to put that % up size injectors in .
If the pick up on the engine is set up the same as that on the ej18 and u get the firing order the same as u need for ej22 it would work .
as with the idle i would put it down to the o2 sensor not working and it wood be flooding the engine or leaning it out too much .
I am not an expert but i think i are on the right track, if u work on it u can get it to work .
Get an 02 guage as it will tell u where your 02 is at real time and not just guessing it .

[GOD]

One more thing - I'm running a 1991 EJ22 long motor with the manifold, harness and ECU from a 1996 EJ18. Any thoughts on what the best injectors would be? Currently have EJ22 injectors in there, but it's thirsty, as described above.

For the archives: Injectors matched to the ECU seem to be the go, which makes sense in hindsight.

Where the 2.2 engine/1.8 computer/2.2 (red) injectors setup was rough as guts and thirsty, 2.2 engine/1.8 computer/1.8 (pink) injectors idles perfectly and fuel economy is back near what it should be. There was a slight drop in power, but I'm hoping a good injector clean can fix that.

Dane.

[GOD]

Bump.

Do EJ ECUs like to have an oil pressure signal? I'm working on the old butchered EJ18 harness again, and one of the unknown (and cut off) wires into the ECU is green/white, which is the same as the oil pressure idiot light switch.

Dane.

[El_Freddo]

Bump.

Do EJ ECUs like to have an oil pressure signal? I'm working on the old butchered EJ18 harness again, and one of the unknown (and cut off) wires into the ECU is green/white, which is the same as the oil pressure idiot light switch.

Dane.

Not that I know of - I don't recall an oil pressure wire to the ECU and don't know of a sensor for the oil pressure to the ECU.

The other thing to have a go at is a can of Upper Engine Cleaner if you haven't already done it. My EJ's going really well since I dropped a can of UEC through it, not a lot of crap burn out but there's still a difference there

Cheers

Bennie

[Gannon]

Find what pin the wire goes to on the ECU and look it up on the pin out. Do you have a FSM for that model?