100 rpm variation in idle speed seems like more than I’d expect w/a modern fuel injected engine. That rpm variation sort of points to some kind of air or vacuum leak into the engine. Another thing that can cause overly rich operation is when the engine doesn’t warm up to as hot as it should (usually due to a leaky coolant thermostat) or the computer thinks it remains cold (usually due to a faulty engine coolant temp sensor). The thermostat is a much more likely failure item. Thermostats are common failure items; ECT’s failures are rare, at least as reported here. I"m still guessing this is some kind of air leak tho.
According to the temp gauge it runs mid range between h and C once it warms up so I’d say thermostat is OK, unless it should run warmer than that but I really don’t have actual numbers to go off, our old car ran a bit warmer than that but I know it ran a little warmer than it should have so I can’t even go off that, it had a ton of problems eventually leading to a blown motor so I’m trying not to get to that point here with this one. When it runs good, new plugs in it, it will run real good. When not, it really doesn’t. I don’t hear anything sounding like a vacuum leak, I really need to give ti a good test and plan, since it’s an easy day, to do that later today.
There’s a pinhole leak in that pressure regulator. Replace it.
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A relatively inexpensive shop fuel pressure test would confirm/deny any issues w/the fuel pressure regulator. There should be absolutely no gasoline at all in the vacuum line going to it though. The purpose of that vacuum line from it to the intake manifold is to insure the difference in the fuel rail pressure compared to the intake manifold pressure is constant. The gasoline is sort of sucked out of the injector by the intake manifold vacuum, and that has to be compensated for, otherwise too much or too little gas will be injected. That vacuum compensation allows the ECM to predict the amount of fuel it injects for the particular operating situation simply on the injector time-on pulse interval.
I absolutely agree with db, but I also sure wonder what this comment in your post means. If the AC compressor is creating an extreme load on the crank, you’re going to have operating problems and who knows what codes sending you on wild goose chases.
Can you describe what you mean by the compressor being “locked up”?
One other request; can you post a photo of the spark plugs?
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It will not detect a pinhole leak in the regulator diaphragm.
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If there’s any leak in the fuel pressure regulator diaphragm, there will be gas in the vacuum hose.
Tester
Sure thing, I’ll take pics of the plugs after work and post them.
When I mention the AC compressor, it’s locked when it tries to engage, the belt screeches like anything if I try to turn on the heat or defrost, the AC doesn’t even try to engage it. IT doesn’t look like the belt moves either when it’s doing it but if I don’t run heat or defrost it’s fine. For now, I just haven’t used the heat or anything and it’s OK I want to get the running rich straightened out first then I’ll replace that since it’s not as important, nor does it look fun. I’m sure I’ve worked on worse cars though. At least I can get at what I need to work on on this one so far.
I’ll get the plugs out after work and take pictures of them and post them, I had the last set around here still but I think I finally threw them out yesterday of course.