Nasty Miss/Shake & P1507

[mrCharlie]

Hi everyone. First time poster, long time reader. Got my first Subaru about 6 months ago (from a string of 3 older BMWs), and finding a resource like this where I could ask questions was one of the things that made me comfortable to make the switch.

 

My car is a 99 Legacy GT 2.5 sedan, 5 spd, 163,000 miles.

 

On my way to work this morning, my car started doing something it hasn't done before. My commute is about five miles, the first four are highway. Exiting the highway, coasting to a stop in 2nd gear, I noticed the shifter shaking violently side-to-side. Pushed the clutch in, tried to rev it up, but the engine was very sluggish. After I stopped, the shaking got worse, idle speed was very erratic (dipped to near-zero at one point), and I noticed the Check Engine Light was on. I had almost no acceleration, and the engine was sputtering.

 

My first concern was the dreaded head gasket from the sound (which was, as far as I know, replaced right before I bought the car with the updated part), so I pulled over immediately and shut the engine off. The oil/coolant were fine and it wasn't overheating. I wiggled things like plug wires connection, and stared the car back up--and it ran perfectly fine. The CEL was still on, so I ran to AutoZone, who read it as P1507- Idle speed control aux input. It ran fine the two miles/slow speeds back to work, even with the AC on.

 

I'm pretty comfortable with working on non-major-mechanical kinds of things, as well as troubleshooting, so I figured I'd ask on here to give me a starting point before I started throwing parts at the problem. Looking around on the board, the first things I see to try seem to be the IAC connector and then the IAC itself. Of course, the fact that it is running fine now seems like it will make this a PIA to troubleshoot. Is that a good place to start, and are there other obvious things I should look at? If it is the IAC, would this eBay version work (http://cgi.ebay.com/ebaymotors/90-98-SUBARU-LEGACY-IDLE-AIR-CONTROL-Valve-IAC_W0QQcmdZViewItemQQcategoryZ38634QQihZ019QQitemZ8077429814QQrdZ1QQsspagenameZWD1V)? It says 90-98, and for $10 it might be worth it- though the price of a new one doesn't really scare me that much if it would fix the car (I did have a BMW before this car )

 

A few things that might help with context:

 

Right after I got the car, I got the P0420 (Catalyst Efficency) CEL. It ran fine. When I took it to a mechanic for something else, they discovered the front cat was broken internally, so they took out the broken pieces, which did nothing for the light.

 

About two weeks ago, I replaced the spark plugs. The pass side two were different from what I got from the dealer, but the driver side two were the same . I think the driver side two might have been the originals (they didn't look too good) and the previous owner wasn't bright enough to figure out how to get to them. The previous owner also installed a crappy cold air intake (which has no shielding from the engine and is therefore a hot air intake). They did a bad job mounting it, and it had a few small holes rubbed in it from contact with part of the car (light brown electrical connector on the pass side shock tower, though it seemed okay). The filter was also filthy, so I replaced it and remounted so it doesn't contact anything.

 

The car ran a lot stronger after dong that work. It was pinging a little and MPG seemed down, plus the idle speed was inconsistant. Pulling the battery cleared the CEL, but I figured it would come back on, since I did nothing with the cat. A few days ago, it came on while I was headed to work. Car kept running fine, so I assumed it was P0420 finding its way back. Then it went out on its own the next day. From what I understand, P0420 takes a while to clear itself, so this seemed odd. I noticed that the CEL didn't do a test cycle when I start the car (should it?), so I thought maybe the bulb brunt out. Now I think that might have been the first instance of this problem.

 

A few other things:

 

It was really humid/foggy/rainy this morning, as it has been all week. I spent last week in the Smoky Mountains, where it is always humid and rainy. I did some gravel road and higher-elevation driving while there.

 

My car eats oil. About 1 qt/1500 miles. More if its hot or I run it hard (only see blue smoke on hard acceleration).

 

PCV valve replaced about 3 months ago.

 

I topped off the coolant a few days ago. I might have overfilled it a little- went to right around the top line with a cold engine. I also spilled a little when I filled it.

 

On very cold days, the car doesn't idle well right after startup. It bounces around at around 500, and 20 seconds later goes into the normal cold start 1200 or so.

 

Thanks in advance for any advice. I tried to be as through as possible with details. It makes for a long post but I know can help a ton when troubleshooting. I don't like to have something go wrong and fix itself- that usually means it will come back right when you don't want it to. Maybe I'll keep a bike on the roof just in case.

 

Charlie

[mwatt]

Hi everyone. First time poster, long time reader. Got my first Subaru about 6 months ago (from a string of 3 older BMWs), and finding a resource like this where I could ask questions was one of the things that made me comfortable to make the switch.

 

My car is a 99 Legacy GT 2.5 sedan, 5 spd, 163,000 miles.

 

On my way to work this morning, my car started doing something it hasn't done before. My commute is about five miles, the first four are highway. Exiting the highway, coasting to a stop in 2nd gear, I noticed the shifter shaking violently side-to-side. Pushed the clutch in, tried to rev it up, but the engine was very sluggish. After I stopped, the shaking got worse, idle speed was very erratic (dipped to near-zero at one point), and I noticed the Check Engine Light was on. I had almost no acceleration, and the engine was sputtering.

 

My first concern was the dreaded head gasket from the sound (which was, as far as I know, replaced right before I bought the car with the updated part), so I pulled over immediately and shut the engine off. The oil/coolant were fine and it wasn't overheating. I wiggled things like plug wires connection, and stared the car back up--and it ran perfectly fine. The CEL was still on, so I ran to AutoZone, who read it as P1507- Idle speed control aux input. It ran fine the two miles/slow speeds back to work, even with the AC on.

 

I'm pretty comfortable with working on non-major-mechanical kinds of things, as well as troubleshooting, so I figured I'd ask on here to give me a starting point before I started throwing parts at the problem. Looking around on the board, the first things I see to try seem to be the IAC connector and then the IAC itself. Of course, the fact that it is running fine now seems like it will make this a PIA to troubleshoot. Is that a good place to start, and are there other obvious things I should look at? If it is the IAC, would this eBay version work (http://cgi.ebay.com/ebaymotors/90-98-SUBARU-LEGACY-IDLE-AIR-CONTROL-Valve-IAC_W0QQcmdZViewItemQQcategoryZ38634QQihZ019QQitemZ8077429814QQrdZ1QQsspagenameZWD1V)? It says 90-98, and for $10 it might be worth it- though the price of a new one doesn't really scare me that much if it would fix the car (I did have a BMW before this car )

 

A few things that might help with context:

 

Right after I got the car, I got the P0420 (Catalyst Efficency) CEL. It ran fine. When I took it to a mechanic for something else, they discovered the front cat was broken internally, so they took out the broken pieces, which did nothing for the light.

 

About two weeks ago, I replaced the spark plugs. The pass side two were different from what I got from the dealer, but the driver side two were the same . I think the driver side two might have been the originals (they didn't look too good) and the previous owner wasn't bright enough to figure out how to get to them. The previous owner also installed a crappy cold air intake (which has no shielding from the engine and is therefore a hot air intake). They did a bad job mounting it, and it had a few small holes rubbed in it from contact with part of the car (light brown electrical connector on the pass side shock tower, though it seemed okay). The filter was also filthy, so I replaced it and remounted so it doesn't contact anything.

 

The car ran a lot stronger after dong that work. It was pinging a little and MPG seemed down, plus the idle speed was inconsistant. Pulling the battery cleared the CEL, but I figured it would come back on, since I did nothing with the cat. A few days ago, it came on while I was headed to work. Car kept running fine, so I assumed it was P0420 finding its way back. Then it went out on its own the next day. From what I understand, P0420 takes a while to clear itself, so this seemed odd. I noticed that the CEL didn't do a test cycle when I start the car (should it?), so I thought maybe the bulb brunt out. Now I think that might have been the first instance of this problem.

 

A few other things:

 

It was really humid/foggy/rainy this morning, as it has been all week. I spent last week in the Smoky Mountains, where it is always humid and rainy. I did some gravel road and higher-elevation driving while there.

 

My car eats oil. About 1 qt/1500 miles. More if its hot or I run it hard (only see blue smoke on hard acceleration).

 

PCV valve replaced about 3 months ago.

 

I topped off the coolant a few days ago. I might have overfilled it a little- went to right around the top line with a cold engine. I also spilled a little when I filled it.

 

On very cold days, the car doesn't idle well right after startup. It bounces around at around 500, and 20 seconds later goes into the normal cold start 1200 or so.

 

Thanks in advance for any advice. I tried to be as through as possible with details. It makes for a long post but I know can help a ton when troubleshooting. I don't like to have something go wrong and fix itself- that usually means it will come back right when you don't want it to. Maybe I'll keep a bike on the roof just in case.

 

Charlie

 

 

You mention "my car eats oil" and "blue smoke on hard acceleration". This engine may have seen better days. Blue smoke is typically a sign of substantial internal wear which may have been caused by abuse or lack of proper maintenance from the previous owner.

 

You also mention "About two weeks ago, I replaced the spark plugs...." How about the spark plug wires? Tell me they're not the originals at 163K miles? (original wires were red and the manufacturing date of the wires is printed on each one) If they are, replace them with genuine Subaru wires.

You've got more than one problem with that engine but if the plug wires appear to be original, start by replacing them first.

[Olnick]

Might consider changing out the engine coolant temperature sensor. It can cause rough running/idle issues. Although mine threw a definite code when it got weak.

 

Also, I run a bottle of injector cleaner with Techron in the tank every 6 months or so. Can really feel a difference when I do it.

 

Good luck.

[mrCharlie]

I will give the wires a try this weekend. They are only $60, and seem like a cheap and easy starting point. Now that I think about it, the driver side ones say Bosch, and the other ones don't. So I'm sure they'll be a good thing to replace regardless.

 

I was a little disappointed to discover the oil consumption when I bought the car. Fortunately, I didn't pay all that much for it, and it seems to be pretty consistent in how much it uses. The car it replaced, an 89 BMW 525i with ~290,000 miles, didn't even need to be topped with Mobil 1 between changes (but it had enough other expensive problems to send it out the door.)

[johnceggleston]

since 2 wires and 2 plugs are different, it may be evicence of the pass. side head gasket repair. i think that's the side that usually goes. at 90 k miles you are soon due a timing belt, some of your oil leaks may be slowed with new front seals.

 

I will give the wires a try this weekend. They are only $60, and seem like a cheap and easy starting point. Now that I think about it, the driver side ones say Bosch, and the other ones don't. So I'm sure they'll be a good thing to replace regardless.

 

I was a little disappointed to discover the oil consumption when I bought the car. Fortunately, I didn't pay all that much for it, and it seems to be pretty consistent in how much it uses. The car it replaced, an 89 BMW 525i with ~290,000 miles, didn't even need to be topped with Mobil 1 between changes (but it had enough other expensive problems to send it out the door.)

[mrCharlie]

I bought the car from a local guy who sells a lot of Subarus. One of the reasons I went with this car is three of the big things had been done: new head gaskets, new timing belt, and new oil seals. That may be evidence the work actually was done, but I know I would have personally replaced the nasty-looking coolant hoses has I pulled the engine apart like that.

 

Thanks everyone for the advice. I keep the thread updated on how things go as I start working on it (I know how nice that can be for someone else with the same problem).

[mrCharlie]

Just a quick update- the car started fine after work (after sitting 8 hours) and drove home completely without incident. The check engine light was not on when I started. It seems like it took two cycles to reset the light, which I think is about the same as what it was earlier this week when the CEL came on.

 

I won't be driving it over the weekend (out of town, taking my wife's car), but I will pick up the wires and coolant temp sensor.

 

Thanks again everyone for the help.

[mrCharlie]

Another update. I replaced the plug wires late last night- they needed it, one was actually cracked, and the car runs a lot stronger now. After I replaced them (battery was pulled to do so), I took a 10 minute test drive, shut it off for 10 minutes, and drove another 10. Everything seemed great.

 

Car exhibited exactly the same problem under exactly the same circumstances this morning. I pulled to the side and it immediately stalled. I shut the ignition off and immediately restarted, and it ran fine the rest of the way to work. This is good, at least it means that I might be able to know if I've fixed it.

 

I can add to the problem that the CEL comes on about 5 minutes into my drive. When I leave the house, it's still fast idle from startup, and the rest of the drive until where it acts up is steady 55 mph. I've also noticed that it seems like it might be cranking longer on cold start than it used to.

 

I have the engine coolant temp sensor to replace, as suggested. Anything else I should look into? I saw another post on the board where the idle control solenoid was suggested- any thoughts on that? I'm also going to go on the hunt for corroded electrical connectors.

 

Thanks again for the assistance...

[mrCharlie]

Another update on my problems. Still don't seem to be solved, unfortunately.

 

I replaced the IAC valve/gasket and coolant sensor, and put Techron last fill-up. I also replaced a coolant hose that wasn't looking so good, and bled the entire cooling system. Finished the work on Saturday, car worked great until this morning.

 

The CEL tripped again, on the way to work this morning. Maybe this is my car's way of telling me not to go to work anymore. When it came on, I was accelerating fairly hard while the engine wasn't completely warmed up. It seemed to run fine for the next few minutes at a steady 55-60. As I got off the highway, coasting to a stop with the clutch in, the idle dipped well below 500 a few times and started to get rough, then seemed okay the rest of the way to work. While it isn't as bad as before (it didn't stall) it still bothers me that I haven't solved the problem definitively yet, and that the stupid light is back on.

 

AutoZone read the code as P1507, again. I went ahead and bought a code reader (was planning on doing so anyway) so I could check and clear codes myself. Here is the freeze frame data I got from my reader, which is beyond my ability to comprehend:

 

Frame 1 Mod $E1

DTC that caused freeze frame: P1507

Engine RPM: 2337 RPM

Load Value: 1.5%

MAP Sensor: 11 KPA

Coolant Temp: 143 deg F

Short Term Fuel Trim1 -4.9%

Long Term Fuel Trim 1 6.2%

Short Term Fuel Trim3 -100.6%

Long Term Fuel Trim 3 -100.6%

Fuel System 1 OPEN1

Fuel System 2 N/A

 

The guy at AutoZone, when I told him what I've replaced so far, suggested next trying the throttle position sensor and EGR valve. Figured I be better asking here before going the next step.

 

I looked under the hood further, and couldn't find anything obvious as far as vacuum leaks or corroded electrical connectors. That doesn't mean those things couldn't be there, they just aren't obvious.

 

It entirely possible the stupid cold air intake the previous owner hacked in to the car has something to do with the problem. It seems like it was a universal item that someone made work, and it wouldn't surprise me if that had to do with some of the problems the car is having. Unfortunately, I don't have anything to compare it to, but it wouldn't surprise me if the thing isn't hooked up right in some way. Would it be worth finding the factory setup to replace what I have? How would I go about doing this? Anybody want to trade?

 

I observed that the old IAC had some oil in it, and most of the intake hoses in that area were wet with oil. Does it seem right that the IAC hose between the IAC and the intake tube has a T in the middle, which is connected to a T on the hose between the PCV and the engine? (For what it's worth, the old spark plugs did not show any sign of oil contamination, I'm kind of hoping I might be on to solving my oil usage problems with this).

 

I've also observed that the engine cranks longer than it ever used to on cold start in the morning. This is a very recent development, in the same time frame as the idle problems. It's not like it's been enough to be concerning, but it's been enough to notice.

 

Anyone have any ideas on where I should go next? I'm stumped, but I don't want to take it somewhere just yet. I'd have to miss work to take it to a dealer, and I don't know of a local indie that really knows Subarus. And so far, all the work I've done has been net-postive despite not fixing the core problem. I just hope to get everything settled soon so I don't have to drive around in my wife's Saturn.

 

Thanks again for the help everyone. This board has been an invaluable resource.

[nipper]

i think you found it.

 

Is the cold air intake onwe of those never replace filters? if it is it can be dumping a fine oil mist on the intake senor. Those aftermarket units can cause all sorts of problems.

Have you replaced the PCV valve with a subaru part?

 

IAC motor can be picking up oil from the pcv circuit. 1 qt 1500 miles isnt exaclty eating oil, check to make sure the engine isnt leaking any oil.

 

DO you have a haynes manual?

 

nipper

[Gnuman]

Also check for a bad connection between the ignitor and coil pack (also between the ignitor and ECU), as this will cause the kind of intermitant missing that you describe.

[mrCharlie]

The cold air intake does have a never-replace filter on it. I hate the thing anyway (makes the car loud, really just sucks in hot air anyway). I think I'm going to get rid of it before I do anything else to the car.

 

Would a junkyard be the best way to get the whole intake assembly? Any suggestions for a good one to go to not too far from SE Ohio? I saw elsewhere on the board that Pick-n-Pull in Columbus is pretty good. This will be my first time junkyarding, I'm kind of excited.

 

PCV is a Subaru part, and it's only a few months old. The oil seals were all replaced right before I got the car, so no leaks, except for the mess around the PCV. I know it isn't a ton of oil the car is using, but it still annoys me, and I'm hoping by some miracle putting the stock intake on might help.

 

I do have the Haynes manual, and I have the FSM CD from eBay. I'm slowly learning how to use them both.

 

I'll check out the ignitor connections when I get the chance.

 

Thanks again everyone for the help!

[mrCharlie]

Quick follow-up for anyone else chasing this problem...

 

It seems like I fixed my car for the time being.

 

I went through the electrical connections, especially the grounds, and cleaned them with this from Radio Shack. While everything else I've done to the car has helped incrementally, cleaning the connectors and grounds (many of which were green) took care of some of the weird stuff that didn't make sense. My car no longer cranks a little longer than it should, doesn't buck a little when coasting, and turing the A/C on during warmup high idle doesn't cause the RPMs to dip down to 800 and back up when I turn the A/C off.

 

It's running like it should now, I think. Hard to say since I bought the car used and don't have a baseline comparison, but it really is running great now. No more thinking "that's just how it is", it runs like a new car would be expected to.

 

Wish I would have had the sense to start with cleaning connectors, especially since this car used to live in salty Binghamton NY. Lesson learned I guess. I'm pretty sure that everything I replaced helped more than just cleaning would have. I did solve other problems in the process, and learn a lot about my car, so it was all worth it.

 

I'm still going to go back to the stock air intake, assuming I can track one down. Hoping that might help oil consumption.

 

Thanks everyone for the help!

[Olnick]

No more thinking "that's just how it is", it runs like a new car would be expected to.

 

Way to go, mrCharlie--sometimes it just takes persistence and stick-to-it-iveness! But the reward is, as the commercial says, priceless!

 

And there's nothing quite like a Subie doing what it's supposed to do . . . run well.

[mrCharlie]

Well, I spoke too soon apparently. P1507 followed by stalling has hit me the last few mornings.

 

To summarize so far:

 

• Light comes on around five minutes into my morning drive. Car stalls as soon as I stop. I turn it off and restart, and it's fine the rest of the day. This happens every couple of days. I even tried changing my commute for a more gradual warm-up, but it didn't help. The problems are only every in the morning, but not every morning. If I start it in the afternoon, even when it sits overnight, it works fine.

 

• I've lost a few MPG in the same time frame as the stalling. Was getting 26-30 mixed highway/city, at least. Now I seem to be averaging only 20-22 mixed. I'm not really driving any differently than I usually do. The car used to ping and now it doesn't (with all the work I've done) and has more power.

 

• Car cranks longer lately, seems worse on the days the light comes on. Talking about 8 seconds of cranking versus 3. Still, it's a change.

 

• Idle generally isn't all that consistent. On long trips (with no light, car behaving itself otherwise) it idles fast for around 5-10 seconds before going down where it should be.

 

• Problem started after trip to Smokey Mountain NP. Right before the trip, we replaced the plugs (from dealer) and replaced the filter (which was clogged and had small holes rubbed in it) on the ghetto cold air intake with another AutoZone oiled-cloth cone. First tank got 18 mpg, but I had also installed an air deflector for my roof rack. After taking that off, car got 27-30 on the highway, not as good in mountain driving. No CEL the entire time. Light and problems after returning to Ohio.

 

• Car uses oil, always has since I've had it. Used more on vacation, it was hot with a lot of lower-speed mountain driving.

 

What I've done so far, unsuccessfully, to fix it:

 

• Replaced plug wires with OEM.

 

• Replaced IACV and gasket with OEM.

 

• Replaced coolant temp sensor with OEM.

 

• Ran some Techron through the car.

 

• Cleaned the more easily-accessable electrical connectors under the hood. Many of these were corroded, and it seemed to help, but apparently didn't solve it.

 

• PCV and plugs are newer, both OEM.

 

• I finally tracked down the stock air intake, which will be arriving next week. I'm hoping replacing the cheap cold air intake and filter with the stock items will help, and might help the oil usage.

 

• I'm replacing the pads and rotors this weekend. Maybe that's the answer!

 

Anyway, I'm running out of ideas. The intake might help, but if it doesn't, I'm not sure where to go next.

 

I'm thinking the next steps are to look for any electrical connectors I missed, replace the MAF, and replace the coil (probably junkyard on both). I was thinking O2 sensor, but according to my scan tool, the fault is always during open loop, which (as I understand it) means the O2 sensor isn't part of the equation. My current theory is that ghetto oiled cone filter contaminated the MAF, or at least let dust and dirt in during our vacation, but I really don't know. Whatever it is, it seems to be like there is some problem that is affecting the car all the time (lower MPG) and causing the CEL/stalling problem.

 

Any suggestions on what to do next? I keep telling my wife I can do this, and it's cheaper than taking it somewhere, but no results to show for it yet. The nearest stealership is 50 miles, and we don't have a local indie that knows Subarus especially well (which is surprising with as many as we have around here).

 

Thanks!

[porcupine73]

I'm hoping this will be useful as reference...I think P1 codes are manufacturer/model specific; P1507 for my '00OBW says "engine keeps running at higher revolution than specified idling revolution." and and it'll happen after two consecutive driving cycles with fault. (might be different for your vehicle).

 

Says to check for loose intake manifold, IACV, and throttle body, cracks of intake manifold gasket, IACV gasket, throttle body gasket, check for any disconnected/faulty vacuum lines, check throttle cable for freeplay, make sure air bypass line is not plugged.

[mrCharlie]

That speaks well to the possibility of the correct intake fixing the problem, a number of those components are attached directly to it. Here's hoping, I'm getting tired of buying parts.

[tcspeer]

I know you have done a lot but I did not read where you cleaned the throttle body, I think that might be worth a try and dont cost much money. Also you can take the coil pack off and have Auto Zone test it for free. These thoughts may not help but they wont cost you much.

That speaks well to the possibility of the correct intake fixing the problem, a number of those components are attached directly to it. Here's hoping, I'm getting tired of buying parts.

[mrCharlie]

Haven't cleaned the throttle body yet. I'll give that a try. Just use throttle body cleaner on it, right?

 

Thanks for the tip on the coil, I'll have that tested when I get the chance.

[tcspeer]

You can use carb. cleaner in the spray can or fuel inj. cleaner in spray can if they make it. I have carb. cleaner so that is what I use. If you have a Dig.volt multi meter you can test that coil by the instrictions in the Haynes manuel.

Haven't cleaned the throttle body yet. I'll give that a try. Just use throttle body cleaner on it, right?

 

Thanks for the tip on the coil, I'll have that tested when I get the chance.

[mrCharlie]

Okay, so, lots more done to the car since last update. It's running pretty well except for the P1507 & stalling. I replaced the cold air intake with the stock assembly, and replaced the MAF & coil pack with used parts. I also cleaned the throttle body, and cleaned up most of the grounding screws that I could find (and coated the with di-electric grease).

 

Since the problems have persisted, I took the car to a local Subaru mechanic. He spent a few hours checking it over, testing, etc but had no luck finding anything that could be causing my stalling problem. He did find my alternator had a failing bearing (loud!), and replaced the alt with a Subie rebuilt for around $125 installed. Anyway, the mechnic seems okay but I do wonder a little (he suggested Bosch +4 plugs and BP gas). Mechanic also cleaned up rust around the filler cap which was causing a code (P0440).

 

As I said, it's running very well now except for the stalling. The CEL symptoms have changed a little. Now, the light generally only comes on when I push in the clutch when coming to a stop. It still generally happens about 5-10 minutes in, usually in the morning or when it's very wet out. Does not do it every time. I've also noticed, under similar circumstances when it does not stall or throw a CEL, the idle dips well below 500 with clutch in coasting to a stop.

 

All I can figure out to do is a new battery (mine has been crusty around the terminals lately, and might be the original- so I am concerned). I've also seen here on the board (http://www.ultimatesubaru.org/forum/showthread.php?t=63050&highlight=1507+neutral) that my neutral postion switch could be the problem. Any insight on this? How hard is this to install?

 

Any other thoughts?

[mrCharlie]

 

Finally, after months of struggling and frustration, I've solved my P1507 and stalling problem. It turned out to be the neutral position switch (aka neutral safety switch) on the transmission. The part wasn't expensive, and it was pretty easy to install.

 

Before I installed the switch, I was to the point of stalling 3-5 time a day. It was okay, albeit a bit rough, right after startup. As the car warmed up, the stalling would begin. The higher the speed I would come to a stop from, the further below idle speed my RPMs would drop. Sometimes they would come back up, but if I was stopping from highway speed, it stalled. Was fine again after I restarted. After the car warmed up fully, it ran fine without stalling.

 

Another problem this solved was eliminating a lot of bucking whenever I let off the gas. Shifting is also much smoother than before. It seems like, in general, the rpms fall much more slowly than before. The other difference I've noticed is the high idle during warmup lasts much longer. Previously, the RPMs settled down to 700 after only about 15 seconds. Now the elevated idle it lasts for several minutes- and when I come to a stop during warmup, it initially falls down to around 1200 and then settles down to 700.

 

While fixing the heart of the problem turned out to be easy and cheap (plus the difference was dramatic), I'm in a way glad to have gone through all of this and I have a car that runs like a new car because of it. It was "good enough" before the ordeal that I would have left it alone, but now it's great. Hopefully all my ordeal will help someone else having the same problem I had. Now I can finally move on to working out some of the other issues my car has...

 

Thanks again everyone for all the advice and encouragement.