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Okay guys, Im new to the forum but would really appreciate some help on some discoveries I have made on my car recently. I have a 2004 Honda Civic LX. 108,000 Miles. Bought it a year ago from a kid who from what I could tell took really good care of it. I've had very minimal problems on it.

I decided to clean my throttle body the other day and after taking the Airbox & Air Filter Box off I noticed that my Variable Vale Timing Solenoid (VTEC Solenoid) was not plugged in which is interesting becuase I haven't had any check engine lights or OBD Codes at all. After searching forever for the sensor head it needed to be plugged into I couldn't find anything. Decided to look at my brothers 2002 Civic EX and see where the sensor comes off the wire harness to give me a better idea where to look. After taking a look at his Solenoid I noticed the solenoid in his car was plugged in but that the Soleoid Assembly also has a Oil Pressure Sender/Switch Plugged into the bottom of the housing which was alarming to me becuase mine does not.

I decided to pull it off and take a look at it and found that mine has a 12mm Hex Bolt instead of the sensor head for the oil pressure switch and the oil pressure switch is missing on mine (Pictures Attached). At this point I had no clue what was going on or why these sensors were not there and why my solenoid is not plugged in with nothing to actually plug into.

I then got curious and took the wire harness apart to see if something had been cut off or snipped. After digging in there I found where someone had spliced 2 wires together. (Pictures attached).

I would appreciate anyones help and thoughts with what this could mean or what the previous owner did before I bought it?

Why the Oil Pressure Switch/Sensor is missing and why my VTEC Solenoid is not Plugged in and has nothing to plug into?

Does this mean my VTEC is not kicking in or working?

Photos to show what I am describing below,


Any help or thoughts would be greatly appreciated. Thank you!

 
Rep Power: 512

LX didn't come with VTEC. It came stock with a D17A1 (1.7L SOHC non-VTEC).

A couple speculations here:

1. D17A2 swap was performed, so you actually have a D17A2 under the hood being controlled by a D17A1-compatible ECU, and thus would not be able to control VTEC. You can determine this by looking at the engine block stamp (front end of engine, about halfway down the bottom end, just inboard of the transmission).
2. D17A2 head was put on a D17A1 block. Not many people have access to engine hoists, so this is a possibility since it's an easy driveway swap. Nevertheless, same applies here, non-VTEC ECU and the head with VTEC parts that aren't plugged in because there aren't any connections for those.

In either case, unless the previous owner swapped in a VTEC ECU but didn't swap the engine bay wiring harness or install a VTEC controller (e.g. A'PEXi VAFC-II; less likely since you didn't mention seeing it anywhere, and it'd definitely be out in the open), VTEC wouldn't be engaging. Seeing as how the VTEC components are looped off (a bit concerned with the spliced one, since I don't have a wiring diagram handy right now), I'd venture a guess that the setup you have is a D17A1 ECU, D17A1 block, and a D17A2 head. The only one I'm sure of is the D17A2 head at this point, the other 2 are pure speculation

edit: looked it up. Brown/Yellow is all ground wiring (logic ground). I'm sure it'll be find with it spliced as such.

edit 2: location of engine stamp, it's on the flat part below the arrow. Shamelessly borrowed from a google images search

 
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The splices wrapped in blue tape are factory splices.

 
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@xRiCeBoYx
Thank you so much for the help and feedback on this, I really do appreciate it! This finally starts to make sense with some of the points you make on this, I should have researched more in depth about the LX not coming with VTEC, I appreciate you mentioning that.

I just went and took a look at my engine stamp. I have attached a picture of it.

It reads: D17A - 2221274

Is this the D17A1 that you are mentioning below?

Is there a way to identify what ECU I have in currently? I took a picture of it but dont know if the numbers on it or the barcode give any information regaring it or if that is the actual ECU.

With that being said, is there any problems with having a D17A2 head on a D17A1 Block that I should be concerned about?

@ezone thank you for the input on the splicing. It looked like a good splice job for the most part but didn't konw what to think.

 
Rep Power: 512

so, the D17A is much akin to the D17A2. I keep forgetting about that engine because it wasn't an OEM engine the USDM market, but moreso in the Canadian/Japanese market. These engines get marketed as "JDM" for that reason, and people think they're getting something super fancy bc JDM tag, but in reality, it's a stock 1.7L SOHC VTEC engine. I'm not 100% sure the actual differences (if any, really) between that and the D17A2. Same displacement, compression ratio, bore and stroke. Power and torque ratings are pretty similar/essentially the same on wikipedia. That said, it's more like scenario 1, with a (technically) different engine. Only real way to find out what ECU you got is to take a peep behind the glove box and see what the part number is, then run that in a parts website like www.hondaautomotiveparts.com. I can't recall if the part number sticker is on the bottom or backside, but either way, it's not gonna be fun to get to.

as far as concerns with the D17A2 head on -A1 block (which doesn't seem like your scenario now), there isn't any. If that were the case (and even still in the case you have right now), it'll run without VTEC. To be completely honest, VTEC in the D17 didn't "kick in" like it did in older engines like all the internet memes, so it'll run just fine. Even in my 2002 ex with a stage 1 cam, and full bolt-ons, didn't feel any sort of power boost when VTEC engaged.

 
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@xRiCeBoYx

Hey Man,

Thank you so much for your help and knowlege on this, I appreciate it very much, I am no longer worried about anything or any problems with what I have in this scenario.

Thanks again for your help and for your time to help me out, means a lot!

Cheers!

 
Rep Power: 512

Lol, I've been around this forum for a long while, and I learned a metric crap-ton tinkering with my 2002 (and this forum actually started as a 7thgen specific forum). You're in good hands if you stick around here

edit:
You're welcome!