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Discussion Starter · #1 ·
Back in the fall / early winter I posted about the difficulty I was having starting my MR2 sometimes. It woud seem to start, then die right away. After it would die, I'd have to give it some throttle to get it started. Then it would be fine.

I still have to give it throttle to start it sometimes, but whatever caused it to die right away seems to be getting worse - now the car won't idle well after I do get it started. Normally on a cold morning like today's, it would idle along at 2k. This morning it decreseaed, ever so gradually, until it stumbled and died. It seems to be doing this pretty consistently now.

Does anybody know what's broken? :)
 

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Shadetree mechanic
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I suggest that you remove the large hose attached to the throttle body and check to see if there is a large buildup of hydrocarbon gunk on the butterfly valve in the throttle body. The buildup can become so severe that it keeps the butterfly valve partially open and clogs up some of the small air passages in the throttle body.

Second guess would be the cold start injector or cold start timing switch problem. Before I checked the cold start injector/timing switch, I would perform a tuneup if you have not done it in awhile to make sure that the spark plugs, rotor, cap, timing etc. are still providing adequate ignition.
 

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Discussion Starter · #3 ·
Is there anything else that you'd suggest doing along with the 'tuneup?'

To be honest, I've never had to check or adjust timing on a car. I just haven't done much engine work because my other cars simply tell me what's wrong with them. :) 'Hey, this sensor is bad - can you replace it so I can adjust myself properly? Thanks.'

I'm not opposed to checking or adjusting timing on the MR2 - I just don't know what it entails. :) Everything else you listed is of course fine. I can handle that.
 

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Shadetree mechanic
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EricS has an excellent site. Bookmark it for future reference. This is how to do the timing:
http://padandwheels.com/mr2/timing/timing.html
He also has instructions for cleaning the throttlebody

You can also look in the FAQ section at the top of this forum page for links to other resources.

lol, I feel old

I grew up when dinosaurs roamed the earth: Mustangs, Camaros, Firebirds, Novas, Cudas, Dusters. I spent my youth with motorcyles and then moved to cars and trucks. I grew up under the influence of Cycle Magazine and Car & Driver magazine where the concept of light weight, good handling vehicle was evangelized. Every car enthusiast had a timing light or knew someone they could borrow it from. I am still using the one I bought in 1971. Tuneups were the first things we learned: Reading spark plugs, setting and gapping points, checking the dwell, tuning carburetors by ear, adjusting valve clearance. It was our initiation to motor vehicles. A manufacturer repair manual was too expensive and the poorly written Chilton manual was the only thing available at auto parts stores. A lot of people don't realize how lucky they are to be able to get assistance on this board, all the other automotive boards, and by using the Google search engine.
 

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Discussion Starter · #5 ·
I thought I'd mention another symptom that I either forgot to bring up or hadn't noticed when I first started this thread.

When the car does idle correctly, which is most of the time, there's a very pronounced vibration. It's not audible, but it feels like a thump-thump-thump kind of vibration. The faster the idle (when it's cold), the less pronounced it is. Actually, when it's not idling and the engine speed is higher, it's very smooth.

I've also noticed more smoke lately - especially when it's idling below 1,000 and the vibration is real bad.

Bad plug or wire? I figure if it was something major, like a bad piece of reciprocating mass, it'd only feel worse as the engine ran faster.
 

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Discussion Starter · #6 ·
Weellll, I found some interesting things today. It's pretty warm out, so I decided to investigate the idle problems I've been having. Here's what I found.

Most of the plugs were gapped pretty well, around .045. They all had pretty normal wear, except for one that was kind of sooty. One of the plug wells (#2) was filled with oil.

I checked the PCV hose between the valve cover and throttle body and it was pretty clean with a little oil on the valve cover side.

I removed the intake tube between the air meter and throttle body, though, and found something pretty alarming. In there was a couple ounces of some very viscous, nasty fluid pooled in the meter. It was light brown in color. I have a theory, but I want to hear other ideas, of course. Check this out, first:

I also found what I think is the PCV valve, but one side isn't hooked up to anything. It doesn't reach anywhere close to where I found it, so I assume I'm missing a hose. Nice.

My theory is that, since the PCV valve isn't hooked up, at some point the PCV hose sucked oil into the throttle body and it settled in the meter, being the low point. Here are some pictures. Please help me find out where the other end of the PCV valve (if that's what it is) goes.

The Gunk:
http://www.subaru-svx.net/photos/files/Mr._Pockets/24771.JPG

Is this a PCV valve, and if so, where does the other end connect? (Dead center of the image.)
http://www.subaru-svx.net/photos/files/Mr._Pockets/24772.JPG
 

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Discussion Starter · #7 ·
Well, I figured out that the fitting was not a PCV valve, and just a T. I found where the other end went. I also replaced the spark plugs and cleaned out the throttle body and air meter.

It seems to idle better. It didn't want to start right away, but for the most part it idles correctly. But then sometimes it'll be idling fine at 1000-1100 and then drop suddenly to 500. That's too slow, I gather. If I goose the throttle a little, it'll go back up to 1000 and stay there for a bit. But hten it'll suddenly drop again.

I get the distinct impression that there's a valve or switch that's not doing its job correctly. I didn't look at the idle air controller - I don't even know if this car has one.
 
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