High Idle... Finally fixed

tahiti350 · Post by **tahiti350** » Thu Dec 13, 2007 3:59 pm

My '90 Wagon has started idling high in the last couple of months, and seems to be getting higher. Right now it's at 1400-1500 warmed up (after driving to work) with everything off. Mileage is down a little, 1-2 mpg, aad power is off a little. It still doesn't like to start when cold, and I have to hold the throttle to keep it running for a couple of seconds to let it stabilize.

I've looked at most of the vacumn lines, etc, and can't see anything out of the ordinary. I do have a good scan tool, but I can't find the data port now.

Post by **Legacy777** » Thu Dec 13, 2007 4:36 pm

Your coolant temp sensor may be going out...

tahiti350 · Post by **tahiti350** » Thu Dec 13, 2007 5:10 pm

That's what I was thinking, as the idle when cold is fine once it stabilizes...

Anyone know where the diagnostic port is located? I've hooked up once, but that was over 2 years ago.

86ruguy · Post by **86ruguy** » Thu Dec 13, 2007 5:26 pm

The data port should be under the steering column

tahiti350 · Post by **tahiti350** » Thu Dec 13, 2007 5:27 pm

Thanks, that's what I thought, but couldn't find it this morning. Was in a hurry though. Will look at lunch and find it again.

internetautomart · Post by **internetautomart** » Thu Dec 13, 2007 8:40 pm

what data port?
I thought all we had were those connectors that you hook together

asc_up · Post by **asc_up** » Thu Dec 13, 2007 9:14 pm

isn't a data port for OBDII??

am i missing something here?

scuzzy · Post by **scuzzy** » Thu Dec 13, 2007 9:41 pm

there's a yellow six pin (I think) subaru select-monitor data port that you can use either with vrg3's scan tool or a subaru select monitor.

internetautomart · Post by **internetautomart** » Thu Dec 13, 2007 9:58 pm

scuzzy wrote:there's a yellow six pin (I think) subaru select-monitor data port that you can use either with vrg3's scan tool or a subaru select monitor.

pics?

scuzzy · Post by **scuzzy** » Thu Dec 13, 2007 10:25 pm

internetautomart wrote:
scuzzy wrote:there's a yellow six pin (I think) subaru select-monitor data port that you can use either with vrg3's scan tool or a subaru select monitor.
pics?

sorry, it's nine pin.

http://www.graphics.cornell.edu/~v/b10scan/

tahiti350 · Post by **tahiti350** » Fri Dec 14, 2007 6:04 am

Okay, looked at that one this morning, and thought that was it, but can't find my Subaru adapter.

Data port/diagnostic port/the connector that you hook to to see what the car is thinking... whatever.... I couldn't remember the "proper" term, but looks like most figured out what I was talking about.

internetautomart · Post by **internetautomart** » Fri Dec 14, 2007 3:16 pm

scuzzy wrote:
internetautomart wrote:
scuzzy wrote:there's a yellow six pin (I think) subaru select-monitor data port that you can use either with vrg3's scan tool or a subaru select monitor.
pics?
sorry, it's nine pin.

http://www.graphics.cornell.edu/~v/b10scan/

does anyone know if the software can run from inside windows?
most new laptops lack any serial or parallel ports so I'd need to run a USB to parallel adapter which I doubt is supported by the boot disc

vrg3 · Post by **vrg3** » Fri Dec 14, 2007 4:20 pm

No, it cannot run from inside Windows. You'll need to find an old laptop or a PCMCIA parallel port with DOS drivers.

tahiti350 · Post by **tahiti350** » Mon Dec 17, 2007 6:18 am

Okay, did a little more testing today. Pulled the plug off the IAS solenoid, and the idle dropped to about 800-900 rpm, but really rough. Started pulling plug wires adn the two front cylinders aren't firing, but I have lots of spark at the coil...

Plug wires are 1 year old, plugs at the same time.

So, lack of power, computer correcting to overly high idle, crappy fuel milage, and 2 dead cylinders. Does this all sound like a bad coil??

vrg3 · Post by **vrg3** » Mon Dec 17, 2007 6:41 am

tahiti350 wrote:Started pulling plug wires adn the two front cylinders aren't firing, but I have lots of spark at the coil...

Wait, I don't understand. You found that removing either of the front two plug wires made no difference in how the engine ran? But what does it mean that you have lots of spark at the coil? Could this be two bad injectors?

If you are in fact getting no spark on either of the front cylinders, I would also unplug both front fuel injectors. You can run for a while that way; the engine will run roughly but at least you won't be throwing raw fuel out the exhaust.

vrg3 · Post by **vrg3** » Mon Dec 17, 2007 6:42 am

Oh -- also, it could be a bad ignitor rather than a bad coil.

tahiti350 · Post by **tahiti350** » Mon Dec 17, 2007 1:04 pm

vrg3 wrote:
tahiti350 wrote:Started pulling plug wires adn the two front cylinders aren't firing, but I have lots of spark at the coil...
Wait, I don't understand. You found that removing either of the front two plug wires made no difference in how the engine ran? But what does it mean that you have lots of spark at the coil? Could this be two bad injectors?

If you are in fact getting no spark on either of the front cylinders, I would also unplug both front fuel injectors. You can run for a while that way; the engine will run roughly but at least you won't be throwing raw fuel out the exhaust.

When I pulled the plug wire at the coil it would arc from the coil terminal to the coil mount bolt. As I put the plug wire back on it was jumping about 1/4" to 3/8" to the terminal, but still not firing the cylinder.

Would a bad plug cause both cylinders to drop offline? I swapped the plugs on the passenger side, but didn't pull the driver side plug to look at it, just ASSUMED that the coil was dead at that point...

Maybe I need to look deeper??

vrg3 · Post by **vrg3** » Mon Dec 17, 2007 3:41 pm

The coil can't be dead if it's giving you spark. I suppose it could just be a weak spark, but it's not dead.

A bad plug could cause both cylinders not to fire, yes. If the side electrode is missing or the gap is way too wide, the spark won't properly be able to jump the gap, which it has to do on both sides.

tahiti350 · Post by **tahiti350** » Mon Dec 17, 2007 5:21 pm

okay, I'll check the other plug and see how it looks. Would be great if that's all it was....

Thanks for the sanity check!

tahiti350 · Post by **tahiti350** » Sun Dec 23, 2007 4:40 am

OKAY, next batch of troubleshooting... It's running on all 4 cylinders again, pulls like a freight train, smooth, but still idling high (now about 1600 rpm), and seems overly rich....

I'm thinking AIS is bypassing or bad, and/or a bad temp sensor?

When i disconnect the AIS connector the RPMS drop to around 800, right back to 1500 when I plug it back in again. This is hot BTW.

ALSO, on intial cold start it will start and then die. To get it running I have to give it throttle while cranking, then hold the rpm's up for about 5-10 seconds then it will idle. any otehr starts after that (while warm) are turn key.

vrg3 · Post by **vrg3** » Sun Dec 23, 2007 7:11 am

Try resetting the ECU (with the green and black connectors). It may have learned to keep the IAC valve's duty cycle high to keep the engine from stalling, and now that the misfire problem is solved it's idling really high.

The cold start problem is probably unrelated. Coolant temperature sensor, perhaps?

tahiti350 · Post by **tahiti350** » Sun Dec 23, 2007 6:13 pm

vrg3 wrote:Try resetting the ECU (with the green and black connectors). It may have learned to keep the IAC valve's duty cycle high to keep the engine from stalling, and now that the misfire problem is solved it's idling really high.

The cold start problem is probably unrelated. Coolant temperature sensor, perhaps?

Thanks for the input, but where are the green and black connectors?? doesn't disconnecting the battery for a while do the same thing??

internetautomart · Post by **internetautomart** » Sun Dec 23, 2007 6:57 pm

the green and black connectors are in the wiring nest under the steering column.

vrg3 · Post by **vrg3** » Sun Dec 23, 2007 8:53 pm

Disconnecting the battery and pressing the brake pedal may do it, but not necessarily as reliably. Give it a try; if it doesn't do the trick, then try the connectors.

For information on the green and black connectors, read the sticky threads and look for the post on how to read ECU trouble codes.

internetautomart · Post by **internetautomart** » Sun Dec 23, 2007 10:17 pm

vrg3 wrote:No, it cannot run from inside Windows. You'll need to find an old laptop or a PCMCIA parallel port with DOS drivers.

got an old laptop
made a boot disk
now I need to make the cable and find the connector on my car.

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High Idle... Finally fixed

High Idle... Finally fixed