edrach Posted September 28, 2005 Share Posted September 28, 2005 Finally managed to get the codes off my '91 Legacy. Car has 155K miles on it and runs well (my daily driver). Since I'm more used to the '80's cars, these codes mystify me a bit. The CEL just started flashing occasionally about a month ago. Last weekend, the timing belt and water pump were replaced but that shouldn't have anything to do with the codes I got since I'm still getting them (just not as many as there might have been since I disconnected the battery during the timing belt/pump work). Here are the codes: 35 CPC 24 Idle control 23 MAF 21 Coolent Temp sensor 11 Crankshaft speed The CPC seems to be the most prevalent and they might all be related to one common cause (he said hopefully). I think the CPC code has something to do with the charcoal cannister (can they actually go bad?). The idle thing might be correct since the idle is a bit slow (600) and uneven. Also, my gas mileage is down to around 23-24 on the highway compared to when I got the car two years ago. (Just looking for someone to point me in the right direction before I start reading in the Factory Manual). Thanks. Link to comment Share on other sites More sharing options...
blitz Posted September 28, 2005 Share Posted September 28, 2005 Ed, there's only one question in your post, to wit: charcoal canister (can they actually go bad?) Sure they can, along with all the associated control circuits, hoses and solenoids. All these codes were logged by the ECU at once, or over the course of several thousand miles? Link to comment Share on other sites More sharing options...
edrach Posted September 29, 2005 Author Share Posted September 29, 2005 I was asking (without forming the question) for guidance in where I should be looking to resolve these codes. Anyway, these codes were collected in a two day period since I had disconnected the battery this past weekend doing the timing belt; codes started showing up Monday evening and Tuesday and were pulled that evening. Ed, there's only one question in your post, to wit: Sure they can, along with all the associated control circuits, hoses and solenoids. All these codes were logged by the ECU at once, or over the course of several thousand miles? Link to comment Share on other sites More sharing options...
blitz Posted September 29, 2005 Share Posted September 29, 2005 Thanks Ed, sometimes the answer is in the background info. It's possible that more than one problem is causing the codes. My first move would be to verify the integrity of all the underhood connectors (and the evap connectors) by dissconnecting and reconnecting each one several times, to clean the contacts. Next I'd verify the integrity of all the vaccum lines (including the evap lines). Look for cracked or dissconnected lines. Check the PCV system. Inspect the intake plumbing for leaks or cracks. Measure the coolant temp sensor against the book specs, it might be going bad. Link to comment Share on other sites More sharing options...
edrach Posted September 29, 2005 Author Share Posted September 29, 2005 Thanks for the update; this should keep me out of trouble for a few hours this weekend. Thanks Ed, sometimes the answer is in the background info. It's possible that more than one problem is causing the codes. My first move would be to verify the integrity of all the underhood connectors (and the evap connectors) by dissconnecting and reconnecting each one several times, to clean the contacts. Next I'd verify the integrity of all the vaccum lines (including the evap lines). Look for cracked or dissconnected lines. Check the PCV system. Inspect the intake plumbing for leaks or cracks. Measure the coolant temp sensor against the book specs, it might be going bad. Link to comment Share on other sites More sharing options...
blitz Posted September 29, 2005 Share Posted September 29, 2005 Sorry I couldn't be of more help. But being the owner of the vehicle gives you the advantage 'cause you know the vehicle's service history. It goes without saying that if something hasn't been looked at in a while, that's always a good place to start. Check the the easy stuff first (hoses, electrical connectors, grounds, etc.) Link to comment Share on other sites More sharing options...
edrach Posted October 1, 2005 Author Share Posted October 1, 2005 Oddly enough, I might have accidently discovered a reason. Three days ago it started raining (not unusual for Seattle) and I clicked on the Defrost/Heat on the front panel. Idle increased to around 800 (where it really belongs) and smoothed out due to the fact that the A/C is kicked in during Defrost. I haven't had a CEL in three days now! Looks like the idle control code might have somehow caused all the errors. Now to either kick up the idle or maybe look for a idle control device (Austin suggested the IAC). I'll post whatever success I have with the solution. Link to comment Share on other sites More sharing options...
Legacy777 Posted October 2, 2005 Share Posted October 2, 2005 Clear the codes, drive the car and see what codes come back. The Canister purge solenoids going bad are typical, and typically aren't a huge issue. They can cause idle issues some times. The coolant temp sensor. Even if the sensor measures ok, they can be bad. For less then $20, I always recommend replacing them if they are in question of being bad. Link to comment Share on other sites More sharing options...
edrach Posted October 2, 2005 Author Share Posted October 2, 2005 Now that the rains might abate long enough for me to disconnect the battery, I can clear the codes and see. For the time being I've tweaked the idle slightly by adjusting the throttle stop screw about a quarter turn. I've pulled a purge solenoid from a PAP car, but I can't believe the electrical part is bad; I think I'll make sure the used one I pulled is clean and working and install it. It's certainly easier than the IAC on the throttle body. I don't have a problem with the temp sensor since the temp guage always comes up to the same spot when the engine is warm and never does anything "funky." I'll also be checking/insuring the ground connections on the engine. Thanks for the feedback. Clear the codes, drive the car and see what codes come back. The Canister purge solenoids going bad are typical, and typically aren't a huge issue. They can cause idle issues some times. The coolant temp sensor. Even if the sensor measures ok, they can be bad. For less then $20, I always recommend replacing them if they are in question of being bad. Link to comment Share on other sites More sharing options...
Olnick Posted October 2, 2005 Share Posted October 2, 2005 I have a problem with the temp sensor since the temp guage always comes up to the same spot when the engine is warm and never does anything "funky." You might want to reconsider on that one, edrach. My '95 L did the same and a new temp sensor made a tremendous difference in running & idling. The code is probably there for a reason! Link to comment Share on other sites More sharing options...
edrach Posted October 2, 2005 Author Share Posted October 2, 2005 If the temp sensor code comes up againg after clearing the codes, I'd certainly do that. You might want to reconsider on that one, edrach. My '95 L did the same and a new temp sensor made a tremendous difference in running & idling. The code is probably there for a reason! Link to comment Share on other sites More sharing options...
Cougar Posted October 2, 2005 Share Posted October 2, 2005 Am I right in thinking that there are two temperature sensors for this model? One for the ECU and one for the gauge. You might want to reconsider on that one, edrach. My '95 L did the same and a new temp sensor made a tremendous difference in running & idling. The code is probably there for a reason! Link to comment Share on other sites More sharing options...
beezer Posted October 2, 2005 Share Posted October 2, 2005 Yes there are 2, one for the gauge and one for the computer. Both are located in the same area. The coolant temp. sensor has a has a larger brass fitting and the temp. gauge is much smaller. Link to comment Share on other sites More sharing options...
edrach Posted October 2, 2005 Author Share Posted October 2, 2005 Thanks, I'll look for the second one. Yes there are 2, one for the gauge and one for the computer. Both are located in the same area. The coolant temp. sensor has a has a larger brass fitting and the temp. gauge is much smaller. Link to comment Share on other sites More sharing options...
gbrand Posted October 3, 2005 Share Posted October 3, 2005 Check purge solenoid resistence-bet you find yours is infinite(open) To see if that is realted to your problem can plug the vac hose and install a 10 Ohm or so resistor to "simulate" a good solenoid. wattage rating needs to be 14.4 watts or better. prolly series-parallel some from RS will work. If you are ggetting multiple codes after clearing them, may want to check alternator if no obvious problems.... Link to comment Share on other sites More sharing options...
Legacy777 Posted October 3, 2005 Share Posted October 3, 2005 Now that the rains might abate long enough for me to disconnect the battery, I can clear the codes and see. For the time being I've tweaked the idle slightly by adjusting the throttle stop screw about a quarter turn. I've pulled a purge solenoid from a PAP car, but I can't believe the electrical part is bad; I think I'll make sure the used one I pulled is clean and working and install it. It's certainly easier than the IAC on the throttle body. I don't have a problem with the temp sensor since the temp guage always comes up to the same spot when the engine is warm and never does anything "funky." I'll also be checking/insuring the ground connections on the engine. Thanks for the feedback. Don't touch that throttle stop screw. That's a big no-no. They are preset from the factory to flow a certain amount. I've heard of several people messing with that screw, and once they figured out the real problem, they had idle issues. By messing with that screw you are fixing the symptom and not the problem. As it was mentioned, there are two temp sensors, the dash one has no effect on the engine temp sensor. Also, as it's been mentioned, there may not be a code, and everything may work "ok", but the coolant temp sensor may be lazy or not work as efficiently as it should. Like I said, they're less then $20. Just replace it if it's at all suspect. It's a good preventitive maintenance item anyway. Link to comment Share on other sites More sharing options...
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