EJ202 TB coolant hose delete - will these create any issues ?

[Steptoe's photos]

I found it convenient just to delete the throttle body coolant inlet and outlet hoses and just cap things off. I have now noticed that the throttle body on my late 1998 Forester's EJ202 NA also has a three wire something on it that may be an ECU input ? or is it controlled by the ECU to do something? I have done three or four good trips in it , with the final trip having some real issues , maybe coincidentally after I added top grade premium 98 RON (Australiain RON, not same as US RON) instead of the usual base grade 91 RON fuel. Massive all four cylinder cut outs initially up mountain passes etc, but continued on on the plains on the way home. Just wondering if I have caused something, or the 360,000 km coil, leads or fuel pump are starting to tell me something. Or it is the fuel, which some have repoted similar weird, unexplained issues running these on premium

[idosubaru]

Can you post all the codes you’re getting? You’re positive it’s all cylinder misfire codes?

I think that’s the idel controller. The three wire part? Look it up and see if it looks the same as what you’re looking at  

I’ve removed them on older fuel injected non turbo subarus down to temps well below zero without issue.   If the idle controller is expecting coolant maybe it’s freaking out?  Don’t know. 
 

Higher octane alone shouldn’t matter. 
 

 

[Steptoe's photos]

yeah, thanks Ido.... at this stage I have yet to read any codes. I am still wondering if it is OBDi or ii

I have seen a reference in the Australian models manual - to OBDii

A mate with Fuji fluids in his veins thinks it being a 98 make date is still only OBDi

The diagnostic plug below steering column looks OBDii , has five wires behind it

I no longer have free reign over the workshop tools (ie Snap-On diagnostic  )

due to business being sold ...new owner might try to invoice me

I am still to learn how to read otherwise or even get a cheapy reader.

The only time CEL came on was after new leads, then it never showed again after new NGK BKR5E-11 spark plugs.

I have also looked closer at the idle speed control device my post was asking about - and can see that the coolant is only coming into contact with it to stop it freezing up.

Idle speeds have been very well mannered.

The cut out certainly felt like all four but I think the AWD magnifies the impact on the panic circuit in brain. I have written in another post that I found two leads were duds. Out of two original sets of these leads, I still could not make up a set of four measuring within spec. Three were good, the fourth was 15,500 Ohms where 15,250 was upper allowable of the range. I bought a new set of leads Eagle Eliminator - made locally to me within 300km away - not a distant foreign mass production crowd, and trusted with my LPG turbo toys - fitted them THEN the first time a CEL has come on. The new plugs fixed the light.

Who tests components before they get any trouble? Right?

Electronic oil pressure gauge now in the line after the under bonnet fuel filter and reading just under 40 psi stationary. 

Test drive is next when the day cools down, or turns over another fresh day :), which is promising to be even hotter 37 deg C

Edited March 18, 2023 by Steptoe's photos

[idosubaru]

21 hours ago, Steptoe's photos said:

yeah, thanks Ido.... at this stage I have yet to read any codes. I am still wondering if it is OBDi or ii

I have seen a reference in the Australian models manual - to OBDii

A mate with Fuji fluids in his veins thinks it being a 98 make date is still only OBDi

The diagnostic plug below steering column looks OBDii , has five wires behind it

I no longer have free reign over the workshop tools (ie Snap-On diagnostic  )

due to business being sold ...new owner might try to invoice me

I am still to learn how to read otherwise or even get a cheapy reader.

The only time CEL came on was after new leads, then it never showed again after new NGK BKR5E-11 spark plugs.

I have also looked closer at the idle speed control device my post was asking about - and can see that the coolant is only coming into contact with it to stop it freezing up.

 

Try to read those codes. That's the best starting point. Oh you're probably OBDI?  Quick google suggests AUS didn't have any Subaru OBDII in the 90's so yours probably is OBDI. Have you see that process for getting the car to flash the codes for you?  Maybe you don't need a scanner?

I think you just plug in the connectors and the check engine light flashes the code to you, not sure where you'll find these in a RHD 98 For but the connectors may look like this:

 

It got down to about -10 Celsius where I used to live and did TB coolant bypass without issues. 

[idosubaru]

This might be a good tutorial on reading OBDI codes but it's a legacy not forester and USDM: 

https://www.surrealmirage.com/subaru/engine.html

[Steptoe's photos]

Thanks Ido...you continue to excell yourself with those efforts.

Appreciated

Sort of going off tangent to main heading but so are the gremlins in my Foz

Our EJ202 SF got the ECU as a bolt to the engine block back of #3, but we got those green plugs and black plugs to connect in correct sequence to get something out of the ECU

Also have what I thought was result of some mad man settling frustrations out down there - two bare long male pins, black wires. I thought they had been pulled from a plug, but wiring diagram shows and lists them as earths for diagnostics !

I have a few pieces of the AUDM manuals by Subaru for 1998, but mine is MY 1999 so hoping stuff is the same for most of it. I have found the instructions on how to read codes etc via those plugs. Actually plan to get same plugs from a wreck to make up a switch box to plug in down there yet operate from the pilot's seat for human comfort sake !

And not trying to correct anyone or anything  on OBDii compliance or convenience , I wonder if manual has more differences than what I have found so far ....

 

[Steptoe's photos]

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