Ah, good evening my fellow 3geezers. Gather around and let me tell you the story of the mysterious TW sensor. Some of you may have already heard of this guy, but for those of you who haven't, this should be valuable information for you.
Take a look at your EFI engine, and you'll see two sensors above the distributor, under this thing with two vacuum hoses coming out of it. The one on the left, with a green plug, is a temperature sensor. It simply controls when the cooling fan goes on and off, when the car is off. Right next to it, on the right, with a beige plug, is the more important TW sensor. Some places will call it a ECT (engine coolant temperature) sensor, or just a temperature sensor. This guy is likely to give you a lot of grief.
Having trouble starting? Does it just crank and crank? Does it act like it floods? Does it feel like sometimes your car runs like shit, rough acceleration and idle? Well, first thing to check is your main relay, the solder points could be loose. But that's a whole other story, just Google "main relay site:3geez.com" to read all about it. At first that's what I thought my prob was, so I resoldered the relay, only to find it sorta fixed what was wrong, so after some poking around, I narrowed it down to the TW sensor.
Well, I was a complete moron and didn't bother to check what code the ECU LED was throwing. Sure enough, it was blinking 6 times, indicating the ECT sensor was bad.
Now, here's where things get tricky. You'll prob like be like "Well, ima just head down to Kragen and grab one". When I did Google "TW sensor site:3geez.com" I even found ppl here saying they'd just pick up at Kragen. Uh-uh.
Kragen will sell you this guy:
You can even ask them and they'll be like "Oh yeah, temperature sensor? Yeah that's the guy." NO! THIS IS WRONG! They'll sell you the one on the LEFT, with the GREEN PLUG. This just controls the fan and won't do shit for your car running like shit. So you'll go back and be like "Uhh, I need the OTHER temperature sensor", and they'll be like "Nah mang, that's the only one I got mang". As far as they know, there is only one temperature sensor they got for our cars. They dunno shit.
So I called around. Autozone, Pep Boys. They only have that one too. Shit. Sure I can find one online, but it comes from back east, takes a week, and I need one now because I'm tired of my car running like crap and being a bitch to start.
BTW, the TW sensor does a great deal, I've found. It's what tells the ECU how much gas to give the engine, based on its temperature. If the engine is cold, it'll give it more gas, and if it's hot, vice versa. This is especially important when starting. With a bad TW sensor, the ECU thinks the engine is always cold, so it'll give it too much gas, you'll sit there cranking and cranking, and the engine floods. This happened to me once, leaving me stranded in a grocery store parking lot (BTW, this is also a symptom of a bad main relay, which I also then fixed). So, a temporary solution, which I found here on the site, is the "paperclip method", haha. Just stick a cut paperclip in the TW sensor plug. This gives a closed circuit to the ECU from the sensor plug, making it think the engine is always warm, so it won't give it too much gas. This saves you from flooding it, however, it makes starting a bitch, as you gotta give it just the right amount of gas as you crank it, then rev it a little before it'll idle properly. If you don't, then it dies, since the ECU doesn't really know what to do. Man, it was like I had a carbed 3gee again! Those damn carbs! :p
Anyway, I just decided to hit up the dealer. Capitol Honda here in San Jo knew exactly what I was talking about, pulled up the Honda part number, but then they didn't have it in stock. No! But wait, he was kind enough to tell me the Honda on Stevens Creek had it. What a guy!
And here it is, the guy that saved me from these past 2 weeks of grief:
Ouch! 40 bucks!
Here are the old sensors:
The bigger one is the sensors that controls the fan, the green plugged one, the wrong one Kragen sold me. It was working fine, but I went ahead and put in the new one anyway.
And here are my shiny new sensors installed:
And thus concludes my adventures with these damn sensors. The car runs like a champ now, starts like it's brand new, just cranks over about three times (rrr, rrr, rrr), and vrooooom it's goin. Also acceleration and idling feel a lot smoother. As someone on here said, "it feels like a new car".
Change your TW sensor, you'll be glad you did!