Well there goes that theory. Crap. Just wasted $45. Thanks for checking for me!

I'll see if I can cancel the order...

 

I'm now leaning towards alternator. It started in limp mode again this morning, and when it started to crank I heard the belt squeal. I bought a junkyard alternator via ebay because I broke the stud off of mine when doing the swap. It's getting worse, as in, it's failing to start more often. My thought is that it's binding when starting, and more resistive while running which is causing a rougher idle.

I'm reluctant to go do trial-and-error since it's an expensive part if i'm wrong...

 

Now I got a new code: P2101 Throttle Actuator Position Performance and P0606 PCM Processor Fault. The throttle body is still coming so I'll see if that fixes anything.

It's just weird that the TB or PCM would suddenly go bad since they're the same as before the swap.

 

Either your ECM is bad or needs a reprogram.

 

Yeah, I've been hoping it was something else but I'll get that done. I don't know anyone around and I hate the dealer. I'll look for someone in AZ that can do it.

 

Dealer is replacing the ecm under the emissions warranty

 

Good. Let us know how it turns out

 

Update: Since I replaced the TB on Friday I haven't had a starting issue, but the idle issue remained.

The dealer replaced my ECM but no change in the idle either.

Here's what I did: I came home, sat in the driveway, and vacuum was solid at 25inHg, with or without A/C. Then I went out to the quiet main street and made some loud noises (WOT pull in 2nd). I came back and the vacuum was at 20inHg. Turned A/C on and still idled pretty rough and vacuum of ~21inHg. I'm wondering if my MAP sensor is finicky. I noticed it'll instantaneously change 5inHg and the engine idle will adjust. I just started a wanted thread looking for someone's old sensors.

 

25" is pretty high. I wouldn't be surprised if that's a false reading. Is boost looking normal?

 

Yeah boost looks pretty normal. When I did the WOT run it peaked at 17psi.

I just cleaned the sensor and it idled well. The pressure shifted around a little but much better than before. It's just one sample though. I'll see how it goes tomorrow. I'm thinking this might be it.

 

It came back during my drive to work. I don't think this gives me any new information tho. I'll try to find a known good and swap.

 

Also, I noticed a lot of oil on my recently-cleaned throttle plate when I swapped it last week. Which makes me think that the amount of vacuum may be real, and/or I have a PCV issue. Also doesn't rule out MAP. The oil is in the intake manifold; the upstream side of the throttle plate is dry.

 

Very common to have fresh oil in the intake manifold.

Talk to John Powell about what could be causing this. Your PCV valve may have failed inside the intake manifold. Not sure if that would cause the abnormal idle vacuum.

What do your valves look like? Dirty? Have they been cleaned.

 

Engine has 800 miles on it. Granted, I didn't clean out the IM before swapping the engine, but the amount of fresh oil on my TB seemed concerning considering I only went a day or two between cleaning the TB and swapping it.

Looks like I have a couple of holes to explore. I'll see which ones have rabbits and which are real.

 

Also, I didn't even realize the IM had the PCV valve in it till this week:S Used to them just sticking out of the valve cover.

 

John recommends replacing the PCV valve when you have the manifold off. Especially if it has a lot of miles on it.

Assumming we are talking about original manifold.

EDIT: Did you put a new Intake Manifold gasket on?

 

Yeah, I didn't think about it. Like I said, didn't even realize it was buried in there like that.

Yes original manifold and yes new gasket

 

I went ahead and ordered one. No one has any nearby so it'll come in next week. Still looking for a local MAP to try.

 

I haven't found a local MAP but I did an experiment with my handheld vac pump. I applied vacuum to the map and read the ECM map readings. They were within 1 inHg of the pump's gauge, so I think my MAP is good. The new PCV will arrive early next week and I'll replace that then.

 

PCV is at the dealer and need to go grab it. Not sure if I'll actually pull the IM until after Christmas. I'll clean out the check valve near the MAF just in case it's stupid easy like that. I've been emailing John Powell also.

 

Yeah pulling the intake manifold is not the most fun. Especially when it's 30 degree.

 

It was really easy when the engine was out. I'm kicking myself that I didn't do this then. :S

 

One more thing I'll try before pulling the IM. I filled the oil up to the top of the full marker on the dipstick. Someone mentioned in a catch-can thread that their car "doesn't like to be topped off" and was blowing a lot of oil out of the PCV on the track. I drained it down to the halfway spot on the dipstick and I'll see if the high vacuum issue returns. I'll live with the vibes; they're not that bad really. They may even be smoothing out a bit. It's the high vacuum and voltage drop that concerns me.

 

This is slightly embarrassing. It was a loose ground strap the whole time. I'm glad I found it though.

 

Mine sits at like -20 vac