Hey guys. I'm new here. And I'm sorry if I posted this in the wrong place. Please move it if I'm in the wrong...
Anyways I just bought a Prelude. I was/am so happy with it. I'm just trying to chase down this problem. I have a friend who used to be a big Civic/Integra guy so he's helping as much as he can but I think I'm in less-charted territory lol...
So, I have a 98 Prelude base, right? Had it about a week. It has the worst gas mileage of any car I have ever owned. Literally, it sucks down the gas worse than my 5.9l V8 Jeep. It has 137k miles and seemed to run OK (even though I don't have another Prelude to compare it to)... so I started with the normal stuff: plugs, fuel system cleaner, oil change, etc etc. Still crappy mileage.
Long story short: I have a "B18C" ECU? I have no idea how or why this happened. But my friend had me pull up the carpet and snap a picture of my ECU for him:
And on the cover, someone wrote a bunch of numbers with a sharpie marker and the only combo I recognized was the B18C... and looking up that ECU # of 37820-P73-003 tells me I have an "Integra Type R" or "GSR" or something ECU? I am new to the Honda scene (have owned a bunch of cars, including a WRX), but I still find this amazing that my car even runs with a totally wrong ECU. But I guess it does run like crap. I had someone else drive it today and he said it was slower than a stuck turd.
So what do I do? I know there are probably 1000 options... my friend mentioned converting back to a OBD1 ECU etc etc... but then I might not pass emissions? And I have to get it "chipped"? I don't have a lot of money. I mean, I'd like to get this all figured out as cheaply as possible. I'm not looking for performance right now. Maybe later, but I just want it to be the stock ECU or whatever. But now I'm also reading that I might be f***ed because I have a key immobilizer in the stock ECU...so how am I going to go about this guys? I did find a local guy on craigslist who has a "P5P" ECU, but that looks like it is a JDM one? I *think* I need a P5M ECU... but then I have to get someone to solder the immobilizer chip on the board?
UGHHH.. Sorry for this being my first post. I want to get this fixed so I can FULLY enjoy my Prelude
I knew the previous owner was lying when he said it had never been tuned.
PS: If this isn't the ECU, what is it? Tranny computer? Body control management?
I posted in the other thread about it but you had no info on ECU ID#. It is a ITR ecu, OBD2 and not sure if it's USDM or JDM, there is only a small difference in the 2. One way to find out is try to see how fast you can get the car up to, JDM cars are all limited to 180kph which is like 111.4mph so that will tell you.
You should definitely get a OBD2 P13 or go OBD1 with the ECU of your choice.
No OBD2 ECU's can be chipped to my knowledge so it runs like it does because it isn't meant or tuned for that engine. The butt connectors on your main harness make me cringe...
You seem to have bought a car that's all hacked up.
__________________
New Formula Red 93 BB2: JDM OBD1 H22a/T2W4 Accord Euro R transmission
Last edited by minilogoguy18; 05-07-2011 at 07:59 PM.
I posted in the other thread about it but you had no info on ECU ID#. It is a ITR ecu, OBD2 and not sure if it's USDM or JDM, there is only a small difference in the 2. One way to find out is try to see how fast you can get the car up to, JDM cars are all limited to 180kph which is like 111.4mph so that will tell you.
You should definitely get a OBD2 P13 or go OBD1 with the ECU of your choice.
No OBD2 ECU's can be chipped to my knowledge so it runs like it does because it isn't meant or tuned for that engine. The butt connectors on your main harness make me cringe...
You seem to have bought a car that's all hacked up.
Thanks for the reply. I appreciate all the input and help I can get. I've been talking to my friend about this and he's telling me to just get an ECU from phearable.net and a conversion harness and call it a day. Just not too thrilled about giving up my key immobilizer... if that's even worth anything to the security of my car? Or the illusion of security lol.
I'm definitely bumming because like you said, it's sort of hacked up... Perhaps it was stolen at one point? The Carfax didn't say it was.... Or it was tuned with a different ECU and when the PO tried to sell it he tried putting it all back to stock and couldn't find the stock Prelude ECU? So he throws a random ITR ECU on there?
Your best bet if you want to fix it on the cheap is to try to find a used ECU from someone with a 5th gen 'lude that just did an engine swap or is parting out their car, and get a new wiring harness. You will have the least number of headaches if you just put everything back to stock. You can buy OBD I ECU's with H22 basemaps already on them, but those are not that great either. They are only supposed to get the car to run well enough to drive it temporarily so the car is drivable until you get a real tune. If you get an OBD II p13 and OBD II wiring harness, you can just plug it in and call it day. No tuning needed.
That hack job is not a good sign for how the rest of the car was treated by the last owner.
Your best bet if you want to fix it on the cheap is to try to find a used ECU from someone with a 5th gen 'lude that just did an engine swap or is parting out their car, and get a new wiring harness. You will have the least number of headaches if you just put everything back to stock. You can buy OBD I ECU's with H22 basemaps already on them, but those are not that great either. They are only supposed to get the car to run well enough to drive it temporarily so the car is drivable until you get a real tune. If you get an OBD II p13 and OBD II wiring harness, you can just plug it in and call it day. No tuning needed.
That hack job is not a good sign for how the rest of the car was treated by the last owner.
I know, right? The car has had more than 1 owner, that's for sure. It's almost like one or two guys tried to take care of it while the other two trashed it, Idk. It has Ground Control coilovers (my friend said those were decent for Hondas?), Greddy Evo2 exhaust (not exactly cheap chinese knockoff stuff), etc etc. Some other quality things too. But then that ECU hack job definitely scares me too lol. Why in the world would someone ditch the stock Prelude ECU, splice 3 wires, then replace it with a freaking Integra ECU? Makes no sense.
That ECU would be an improvement over what you have now because you could at least get a H22 basemap on it, but it would still require you to get a real tune if you want your car to run right.
Would that not be semi-close to as real a tune as possible? By real tune, do you mean a pro-tune? I'm so used to the Subaru WRX and Evo world of tuning... where your stock ECU is flashable up to ungodly amounts of power and you can just hook up your laptop with a Tactrix cable and tune it with Open Source software. Through a base map on there and then adjust it from there. Or take it to the dyno and have a pro tune on it. None of this removing ECUs and converting back to OBD1 etc etc.
But my friend keeps telling me if I do this phearable thing, that the guy who does that will know exactly what kind of a tune to send me? Based on what info I give him on my car?
But my friend keeps telling me if I do this phearable thing, that the guy who does that will know exactly what kind of a basemap to send me? Based on what info I give him on my car?
Fixed. Your friend is wrong. A tune and a basemap are not the same thing.
Every engine is different. The basemap that would come preloaded on that ECU would be based off of a tune on some other H22(every H22 is different) in some car(maybe a prelude, maybe not) likely with some mods(who knows which ones) on it. It would be "close enough" to your engine setup to get it to run, but your engine would still need to be tuned (on a dyno preferably by a professional tuner) afterwords to benefit from using a non-factory ECU. A basemap is only intended to be a starting point for a real tune, not a long term solution.
The p72 ECU you already have is fully cabable of running your H22, but you would need to chip it and use the software of your choice to get it tuned. There are many software programs to choose from, all they have their own benefits and drawbacks. Crome is the most common free open source option.
Again, stock ECU + stock harness = less headaches.
If you want something you can tune with a laptop I'd suggest getting the Hondata S300, I love mine and any laptop with the free SManager program installed can tune it. If your car is pretty close to stock you can just tell phearable that and they can upload a stock H22 basemap to it and it will run just fine. Some extra power and mpg though can be brought out of a stock H22 with tuning.
You don't choose what ECU they give you, it will more than likely be a P72 though since a P28 does not have IAB control or a knock board.
Indy, he has a P73 which is an OBD2 ITR ecu which is not supported for any sort of modification. One of the main reasons why he is experiencing terrible performance is because he has no IAB control as the ITR uses a standard single runner IM.
__________________
New Formula Red 93 BB2: JDM OBD1 H22a/T2W4 Accord Euro R transmission
Last edited by minilogoguy18; 05-08-2011 at 08:17 PM.
If you had sereis2 aem i would send you a base map no problem.
As for you p73, at one point in time iwas goint o use one to amke an all motor h22 with itbs but tehn after researhcign it i gave it to my freind for a chipped p72. ANyway, good luck
Indy, he has a P73 which is an OBD2 ITR ecu which is not supported for any sort of modification.
You're right. I thought it was a p72. As you said, a p73 or any OBDII ECU is a no go for tuning.
It probably runs like crap mainly because the air/fuel maps are completely different for a b18 than they are for an h22. Kinda surprising it runs at all.
__________________
BluetopH23a Vtec Swapped NHBP '99 Base
Last edited by indylude18; 05-08-2011 at 09:19 PM.
i was once told by my tuner, that you can chip an obd2 ecu but you only get on crack at it. I dunno, after using different chrome and hondata, stand alones are the way to go IMO.
Thanks for everything so far guys. Yea, I definitely don't have the P72. I have the P73, which my Honda friend told me the same as you guys: it's not tunable and not really an option for me at this point lol.
I guess really the best thing to do is probably roll with the Phearable setup, at least for now. Nothing else seems to make much sense. I mean, I don't wanna drop $$$$ for a standalone EMS, even though I know that's BA. I'm not looking to turbo my car or make oodles of power right now. I just want to get it running right... possibly add some headers/exhaust/etc. Maybe cams at some point. But really, I just want it to run right. It's pretty embarrassing to drive now lol.
Aside from those stupid butt-connector splices, I found more stuff... I don't know what is factory and what isn't. I went ahead and soldered those butt splices anyways to fix that nasty mess. But then I am seeing all these other wires wrapped in electrical tape that are SEMI factory looking... but they go in one color and come out a different color lol. I don't know if anyone here can chime in and decipher and of this rat's nest:
The AutoGuide.com network consists of the largest network of enthusiast-owned enthusiast-operated automotive communities.
AutoGuide.com provides the latest car reviews, auto show coverage, new car prices, and automotive news. The AutoGuide network operates more than 100 automotive forums where our users consult peers for shopping information and advice, and share opinions as a community.
Linear Mode
