Timing/Strange Idle

[Xithael]

Hey all, 

I’m having a strange problem with a fluctuating idle speed in my 1992 Subaru Loyale. When I turn it over, it runs and idles at 1900 RPM, then when it’s been running for a while, it starts to go down then kinda sputters out. I looked this up on google, but mostly what I got from it was “vacuum leak.” I also have to adjust the timing, so I was wondering if maybe that fixes it? I’m a very inexperienced mechanic, at least when it comes to real life. The engine is an EA82, and it’s a bit of a mix and match of two different engines. It’s single point fuel injection. If anyone has any ideas, please feel free to type away down in the replies. 

[moosens]

1900 is double the normal idle pretty much. So that firstly should be addressed. 
 

No CEL going off? 
 

Online manuals are likely found here:https://jdmfsm.info/Auto/Japan/Subaru/--Old Models--/

 

Been a while for me since I’ve had any EA82s but from memory there’s often issues with the CTS coolant temp sensor, or the IAC I think. Closed system for air that’s what google was alluding to. Check for leaks, yes. 
 

Adjust the timing how so? Just the distributor position? You have a timing light ? Should be cheap enough these days. Get a feel for that too although your car is kind of a “set it and forget it” type of deal. 
 

Going forward and not on subject here, be sure to get yourself some timing belts while you maybe can still find them. It’s the drivers side USA that’s the hardest to find since that’s the one that typically goes. 
 

Check for any wobble in your distributor too. Lift the cap and rotor too and grab the top and shake it left right front back. You will be ok with a slight up and down play but should be nothing side to side. 
 

Start there and I’m sure others who run those engines still will chime in. 
 

[SuspiciousPizza]

I'm curious about this engine it sounds like it's had some work done. If this rough idle began to occur after the work was done then it may be a timing issue. If this just started occuring out of the blue, then the first thing that comes to my mind is electrical/electromechanical. 

Checking the timing wouldn't hurt, cylinder #1 is the front passenger-side. Be sure to check your cam timing as well otherwise you're only diagnosing half of the timing. 

Check the diagnostic table in the FSM for rough idle symptoms. 

Don't go throwing parts at it, it may be tricky finding something you may not really need. Although it is a good idea to have spare parts.

:]

 

[Xithael]

On 5/15/2025 at 5:16 PM, SuspiciousPizza said:

I'm curious about this engine it sounds like it's had some work done. If this rough idle began to occur after the work was done then it may be a timing issue. If this just started occuring out of the blue, then the first thing that comes to my mind is electrical/electromechanical. 

Checking the timing wouldn't hurt, cylinder #1 is the front passenger-side. Be sure to check your cam timing as well otherwise you're only diagnosing half of the timing. 

Check the diagnostic table in the FSM for rough idle symptoms. 

Don't go throwing parts at it, it may be tricky finding something you may not really need. Although it is a good idea to have spare parts.

:]

 

Yes, this engine has been some time in the works now. It’s been rebuilt from the block, and hasn’t run in 3 years or so. The cams have been timed, I believe? That’s when you set it to TDC and put the belts on? I believe that it’s been done. I have the manufacturer’s manuals, and I’ve checked about timing it, but since me and my grandpa started from scratch, we also had to put new fluids in, coolant, oil, etc. That ended up meaning that we also had to follow the procedures for warming up the coolant to temp, which is in right about the same area as the timing section, but since it has this issue I’ve been wondering: if it has an exhaust leak, is it worth trying to time right now? Like, if we fix the exhaust leak AFTER timing the engine, do we have to time it again? Thanks for the feedback, 

-Xithael

[Xithael]

On 5/14/2025 at 9:57 PM, moosens said:

1900 is double the normal idle pretty much. So that firstly should be addressed. 
 

No CEL going off? 
 

Online manuals are likely found here:https://jdmfsm.info/Auto/Japan/Subaru/--Old Models--/

 

Been a while for me since I’ve had any EA82s but from memory there’s often issues with the CTS coolant temp sensor, or the IAC I think. Closed system for air that’s what google was alluding to. Check for leaks, yes. 
 

Adjust the timing how so? Just the distributor position? You have a timing light ? Should be cheap enough these days. Get a feel for that too although your car is kind of a “set it and forget it” type of deal. 
 

Going forward and not on subject here, be sure to get yourself some timing belts while you maybe can still find them. It’s the drivers side USA that’s the hardest to find since that’s the one that typically goes. 
 

Check for any wobble in your distributor too. Lift the cap and rotor too and grab the top and shake it left right front back. You will be ok with a slight up and down play but should be nothing side to side. 
 

Start there and I’m sure others who run those engines still will chime in. 
 

CEL is not on. I have a timing light, but it seems that the flywheel should be at 20 degrees towards the passenger side when it’s completely on the other side. I believe the timing light had to be cranked all the way clockwise to get the mark to show up. The distributor is loose right now so as to get it in a position that could be correct, but it may be worthwhile to just buckle it down for now to get some kind of consistency? We have new belts, fortunately my grandpa bought some back in the day. As far as I know, we have all the parts, we just need to put it back together, which we’re not far off from. 

[Xithael]

Unrelated to the replies, but since it was idling normally for a bit, me and my grandpa took it out on the road for a test drive, and when we got back, the crank pulley bolt was so loose that it almost caused the belts to completely fall off, which I can only assume means that we did not torque the bolt. Does this mean we have to re-tension the belts? Thanks

-Xithael

[SuspiciousPizza]

When you get the engine to TDC, what landmark in the engine bay does the distributor rotor point towards? It should point towards the brake master cylinder/brake booster. 

If it doesn't - lift the distributor an inch or two and rotate it (I forget which direction). Remember the distributor gears have a spiral to them, so the rotor will rotate as you insert the distributor.

Bolt it down, it shouldn't be rattling around. Just back off the bolts when you set the ignition timing. This way the distributor doesn't accidentally move when you tighten it down. 

Be sure to have the proper RPM's (≈750, I believe) when you do the ignition timing. 

 

:]

Edited May 17 by SuspiciousPizza

[Xithael]

Hey all, since setting the distributor to somewhat proper idle, the check engine light has started flashing. What do I do about this? I assume this is somewhat normal, as moosens alluded to. Normally I would associate this with complete engine death, but it seems to run fine. The green test plug that is mentioned in either the “how to keep your Subaru alive” book or the engine manufacturers guidelines seemed to make it go away, but I think it was a fluke the time I did it. I’m genuinely afraid to take it up the road and back, but when I did it seemed to handle it just fine and went into 4WD too. Thanks, 

-Xithael

[SuspiciousPizza]

When you go to set the ignition timing, there are 3 connectors you must connect before turning the dizzy does anything.

There is the green under the dash near the ECU.

Then there's the green connector and the white or black connector near the firewall in the engine bay (by the driver side strut tower). These may be a 2 prong connector but there'll be only 1 wire going to the connector. But the two connectors will be right next to each other.

Make sure all 3 of these connectors are unplugged. Otherwise the car is in "learning mode" and the ECU is confused. I'm using improper terminology, I don't have my manuals nor my car in front of me at the moment.

If they all are disconnected and this is a "yeah, no duh" then it may be something else. This just came to my mind first as to what may be going wrong.

:]

[kayakertom]

Those two wires on the driver's side near the strut tower get connected when doing the timing and then disconnected for driving. RPM fluctuations often mean vacuum leaks. Double check your spark plug wires. Clean up the multiple ground connections.

[czny]

If you're lucky, there may still be a timing decal on the underside of the hood, driver's side nearer the front lip of the hood, spelling out the timing & the green connectors.  

My 87 GL has a lot of blow by oil getting into the IACV on the throttle body. It got stuck at 1900 RPM one day until I sprayed some wd-40 down into the valve to dissolve the excess oil.

After that, it would come down to about 1100 then drop down to about 7-800 slowly, which is what it's supposed to do. My guess is that it hydro-locked with oil.

I'm thinking of putting some chore girl pad in each L&R valve cover breather hose to cut down on oil mist getting into the the TBI intake boot.