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2 Idle/Choke Related Questions - EA82 - '88 4x4 GL Wagon


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23 replies to this topic

#1 Deener

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Posted 19 August 2009 - 01:51 PM

Hey folks,

I am just troubleshooting my intermittent goofy idle/rough driving.

Symptoms are:

- CEL comes on here and there (sporadic)
- Runs better when the CEL is off (not much suprise there)
- On a cold start it won't idle the first time. It will start, then reach about 1500rpm's then drop down to 0 and stall within about 3 seconds. Second time I start it, she will stay at idle but seemingly low.
- Sometimes the overdrive won't 'kick' - like I stomp the pedal when going various speeds and there's no response...just a slow climb of the rpm's and the speed of course. However, sometimes it will blast off like a rocket...usually when the CEL is off.

I have cleaned out the MAF and top of the carb (where the choke is..?)before and the CEL went away for a bit but it has returned.

Yes it is a Hitachi Carb and Disty.
Rebuilt Tranny and front Diff last month (positive the downshift thing is combustion related).

Before I go buy new plugs/wires/rotor/cap/PCV/filters, I would like to know 2 details about things I have learned here that may be related

1. Is the Coolant Temp Sensor the wired plug on the passenger side of the radiator? If not where is it located on my engine? I would like to clean it.

2. I have read up and tried to clean out the IAC - Do I have to remove it to clean it properly? I have tried cleaning it by removing the hose but I can't get all of the way inside it. Any special advice on that one?

Thanks a bunch!

Dean

#2 GeneralDisorder

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Posted 19 August 2009 - 09:10 PM

You don't have a choke. You have a throttle body injected engine - carbs have chokes, injection does not.

Clean the IAC - yes you have to remove it.

You can't clean the CTS - it is a thermistor and it is either good or bad. Test it's resistance at various temps and report them back to this post and I'll tell you if it's good. It is located on the left side of the manifold near the thermostat housing. It has a two-pin green plug.

Pull the codes from the computer and find out what it's complaining about or what it has complained about in the past. Likely you need a new CTS, clean the IAC properly, possibly clean the MAF, and replace the O2 sensor and you should be well on your way to a properly running SPFI system.

GD

#3 Deener

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Posted 20 August 2009 - 08:14 AM

Thanks GD. I cleaned the MAF and I did see the CTS. I threw in some new spark plugs because the hood was open. I have to buy a mutilmeter soon, so once I have it I will give it a shot and report the resistance. I have never operated one but it can't be that hard to figure out I am sure. I did see the the post about pulling codes:

http://www.ultimates...t=trouble codes

I don't know how to check the codes yet, but I am eager to try. Can you describe the connectors and where to look for the flashing light...or are they super obvious and right there? I understand the connectors are under the steering wheel to the left, but is that where I look for the flashing LED too?

"With NEITHER test connector connected, and the key in the ON (engine off) position, the light will display codes
that relate to starting and driving..."

Thanks a million again....

#4 Gloyale

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Posted 21 August 2009 - 09:31 AM

You're SPFI car the test connectors will actaully be under the hood, in the corner of the engine bay nearest the driver.

#5 Deener

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Posted 26 August 2009 - 03:16 PM

I went looking for the codes but couldn't find the L.E.D. I popped the cover off of the under side of the steering wheel, then turned the key to the on position and I couldn't see any flashing light anywhere. I am not sure where to look for the L.E.D. Do I need a mirror to see in behind there somewhere or should it be obvious? According to the posting I read I shouldn't have to connect anything to read codes that relate to starting and driving.(?)

I am also going to take a crack at removing and cleaning the IAC today but it looks like I have to remove the power steering reservoir to get at the IAC screws. Looks like two bolts hold it on so that should be straightforward. Is there an easy way to drain the reservoir prior to removal or should I just get ready for the mess?

#6 Txakura

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Posted 26 August 2009 - 06:08 PM

you don't need to pull the reservoir to remove the iac, it's at the bottom front of the throttle body with 4 screws facing forward

the error led is on the edge of the ecu, (bolted under the steering column), facing the driver seat, right in the middle of the box

#7 Deener

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Posted 27 August 2009 - 07:57 AM

Thanks a bunch. I got the IAC cleaned and it now idles much better...no fluctuation. It seems to drive smoother too. I will post the codes when I can get them properly but I am going to pull the CTS first and clean it up. I can see some scale/deposit around where it screws in.

#8 Deener

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Posted 14 September 2009 - 10:52 AM

So I got a multimeter and pulled the coolant temperature sensor. Well, I am not sure if I am using the meter correctly, but I tried setting it to 200 Ohms (I have a selector for 200, 2k, 200k and 2M and I zero'd it first) and with the sensor out, I touched both ends to the electrical connections of the sensor and got nothing. I then heated the bolt part with a lighter and put both ends of the meter on the bolt part and got about a .5 reading. However, I couldn't get a reading when it was cold. Does this mean that the sensor is toast or I tested it wrong? Since my last post here I have removed and cleaned the IAC and before I put the CTS back in, I sanded the scale off of it. The idle is much smoother and stable now but an issue remains...When I start the car cold, it will fire up and die right away. If I start it again, it will idle but really low - like around 400 rmp or so. If I drive right away like this, it bogs down because it's not warmed up. But if I start it the second time and keep the rpm around 2000 for a minute or so, it will drive nicely.

I have yet to pull codes from it because I can't figure out the connectors in the engine properly. There is a white set that looks like they will go together and a green set that looks like they connect as well. There are two more sets (an orange and a black set) that will not connect together. With the key in the ON position, and neither the geen or white ones connected in the engine bay I still don't see anything flashing.

Any thoughts or suggestions?

Dean

#9 The Dude Abides

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Posted 14 September 2009 - 01:35 PM

Thanks a bunch. I got the IAC cleaned and it now idles much better...no fluctuation. It seems to drive smoother too. I will post the codes when I can get them properly but I am going to pull the CTS first and clean it up. I can see some scale/deposit around where it screws in.


What did you use to clean it, how did you clean it.

#10 Deener

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Posted 14 September 2009 - 01:59 PM

To clean the CTS I used sandpaper and then blew it off with compressed air. For the IAC, I pulled it right of the engine and used carb cleaner and my roomates toothbrush!

#11 GeneralDisorder

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Posted 14 September 2009 - 05:37 PM

The CTS doesn't need to be cleaned except for the connections. It does not rely on it's ground connection with the threads for it's function unlike older sensors and the one for the gauge. It is a thermistor and rely's only on heat transfer (which is negligably affected by cooling system deposits).

The 200 setting is too low for the sensor when it's cold. You need to click through the settings on the MM untill you get a reading. IIRC it's up around 2,000 Ohms (or maybe it's 20,000) when it's cold and it drops as it warms.

You should never be putting the probe's on the threaded "bolt part" of the sensor - that has nothing to do with it's reading. You need to test through the electrical connections on the green plug.

You should get a high reading cold, and a low reading warm and it's sounds like your MM is not auto-ranging so you WILL have to switch ranges on it to get a proper reading. I sugest back-probing the connector while it is installed and watch the reading as the engine warms. That will give you a proper idea of the range the CTS is reporting. You can't do more than a cursory inspection with a lighter as you cannot control the temp accurately enough to insure the resistance is low enough at 190 degrees. It may be that the sensor is "out of range" and isn't reporting a low enough resistance till it hits 250 degrees or higher - which is easily obtainable with a lighter but you have no way of knowing for sure.

GD

#12 Deener

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Posted 22 September 2009 - 05:18 PM

Ok, I tried back probing the sensor. I unplugged the green connector and stuck the probes in the female end. I got no reading on ANY of the settings on the MM(ranges are 200, 2k, 200k, 20M). I did this just after I had it nice and hot. I also had the same results cold...no reading from the MM whatsoever when probing the electrical points. I notice that my CTS doesn't look like the ones I see in most pictures that I see. Mine has a green electrical connector, two wires go to the metal part, but my metal part is very short in comparison to what I see online. There is no metal beyond the threads at all. In fact, the metal piece is only about 1/2 an inch long.

I finally retrieved the codes...woo hoo! I got a 21 and a 31 (two dashes, one dot, then three dashes and one dot...then repeat over and over). According to the trouble codes listed here, that says:

21 Coolant Temperature Sensor or Circuit
and
31 Throttle Sensor or Circuit

I double checked the connector for the throttle sensor (on the side of the intake) and it seems fine.

Any suggestions where to go from here? Just buy those two sensors?

Dean

#13 GeneralDisorder

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Posted 22 September 2009 - 05:44 PM

Get them used from the junk yard. Cost to replace them with new parts will be half your next paycheck (maybe all of it).

GD

#14 Deener

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Posted 23 September 2009 - 08:00 AM

Thats kinda what I thought. The Throttle sensor is about 330 new and the CTS is about 100. Unfortunately the junkyard near me doesn't keep much of the older models (Aldergrove Auto Wrecking). I'll give them a shot though. Thanks for all of your help. GD especially. You guys are the reason I am still rolling.

Dean

#15 Cougar

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Posted 23 September 2009 - 08:32 AM

Whenever you have a code that mentions the circuit as part of the possible trouble it is a good thing to make sure the wiring to the sensor in question is good between the ECU and that sensor. In the case of your CTS sensor it sounds like it is open internally. You should see a reading using your ohmmeter using the 2k or no more than the 20k scale of the meter, as Gloyle stated. If you don't get some sort of reading directly touching the sensor contacts then the sensor is open. The ECU will show that as a circuit problem code.

The other sensor code may be due to a bad connection at the sensor. Check the voltages on the sensor leads to see what that shows.

When you get more familiar with using your meter you will wonder how you got along without it.

#16 Deener

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Posted 23 September 2009 - 01:15 PM

Yes, logically I will now find where the wires go to the ECU from the CTS and make sure they are good the whole way. But since I have the wiring unplugged, and I have tested the CTS twice now cold and hot to no avail...woldn't that say that the sensor is toast? The ECU code 21 reinforces that theory, doesn't it? The throttle sensor is connected nicely, I pulled it off and re connected it to be sure. None of the wreckers in my area have my year of vehicle and thusly no parts. That being said, what are the cross compatibility rules for things like sensors and different years/models? I would imagine that for the CTS, it would have to be the same size non-turbo and for the Throttle sensor, it would have to be off of an SPFI model/EA82. Are there any cross compatibility possibilities here?

#17 Cougar

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Posted 23 September 2009 - 01:28 PM

The CTS sensor is bad if you don't get a resistance reading across the pins. It means it is open.

I think you may need to get OEM parts for those things though they may be available from a parts store outlet.

#18 Deener

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Posted 25 September 2009 - 12:57 PM

Well, I put a want ad out for these two sensors and Subex responded within minutes! He is sending me both for about $75 american shipped. Stoked! They are out of a 94 Loyale 5Spd spfi, EA82. Thats the same engine so I assume the sensors will work. Man...I love this forum.

#19 Gloyale

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Posted 27 September 2009 - 10:37 AM

Buy the CTS for an MPFI (turbo) model. It doesn't have the long wirng pigtail on it but it threads in and outputs the same range. It is also only about $25 bucks from any autoparts store (same sensor used in many Toyotas, nissans, mazdas from late 80's and 90's)

I don't know why Subaru used the fancy version with the pigtail for SPFI models..........3-4 times the price:confused:

Buy a *bosch* style FI connector (IIRC #8550?) and splice it onto you're old CTSs' pigtail. Now it will plug right in.

Might be a better option than getting a used one.


as a side note, you should at least test the TPS first. It may have thrown a code for TPS as a result of being unable to control the idle due to the previuosly stuck IAC.

#20 Deener

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Posted 28 September 2009 - 03:30 PM

Good stuff Gloyale. Thanks. I have already told Subex that I will buy his parts so I am not going to go back on him now. I would like to have an extra TPS anyways since they seem very scarce in my area. Whats the TPS testing procedure? I looked at my Haynes Manual and it says to just test two terminals together. Is there a write up on the procedure or is it straightforward?

#21 Deener

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Posted 15 October 2009 - 05:30 PM

So the CTS I got from Subex fit my vehicle and the CEL went off as soon as I fired it up. Thanks again to all of you. I tried to find the bosch type fi connector but nobody carried them in the local parts stores. I will probably try it in the future if this one goes on me. YOU GUYS RULE!!!!!! I gotta go for a rip now...

Dean

#22 Cougar

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Posted 16 October 2009 - 10:23 PM

Thanks for the feedback. Glad you got it fixed.

#23 Deener

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Posted 20 October 2009 - 07:57 AM

Not only did it fix the low cold idle issue, the car is running amazing now. It kicks down at almost any point in acceleration and runs super smooth with more power. The rebuilt tranny and front diff help I suppose, but the CTS sure played more of a bigger role in combustion than I expected. Let it snow so I can show off the gazelle!!

#24 Cougar

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Posted 20 October 2009 - 10:08 PM

Don't go into red shift, the cops will get you.




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