ok i have a strange situation, i just bought this car off of a lot saturday, they got it from a auction.

who ever had it before that started to turn this car into a tuner, so not exactly sure what has been done yet, but looking at the vacuum diagrams there should only be one map sensor.

i am pretty sure it has the h23a1 2.3l engine, but not certain since i know next to nothing about honda, if i remember right it had vtec on the engine, black top, so not sure what generation.

i have two... one is right where it should be located and one is mounted on the firewall with vacuum lines and a t running into the motor, the one in the correct place has a part number ending in 3000 while the one on the firewall ends with 2990, they both appear to be original honda parts, but only the one on the firewall is connected to a plug which someone shorted the wiring on.

i believe the spark plugs are fouled, but i can't be completely sure since i think they changed the map sensor for some kind of mod and i am hoping someone will know what the reason could be for.

the issue i am having comes at two different instances.

1 i am going up hill, the engine seems bogged down about 500rpm or hesitation.

2 i shift and stomp the gas a little and i get the same feel, but if i over-rev a little or pop the clutch and over power it is fine.

i also believe that if i change the spark plugs to performance and the leads to performance as well, in a few months i will probably have the same problem again if the map sensor isn't set right.

i know i can probably try cleaning the spark plugs and see what happens for a base line.

also when i was looking at the car before deciding it was worth getting, which it is even with this going on it smelled like it was running rich ( i could smell gas in the exhaust ) and the battery it had was weak or has dead cells and i know this from past experience with another vehicle and when i switched to the other battery i have the really rough idle stopped and it hasn't died since.

so any ideas on what to try first would be greatly appreciated and any ideas on what might have been modded would help a lot too, i'll post pics tomorrow of the engine and if anyone is interested in seeing the interior and exterior as well, i can snap some of those in as well, mind you it needs a few patches and some things tightened up...

also, the check engine light came on the other day and the oil light flashed on and off, but after i stalled while getting used to a softer clutch it hasn't come on again the past two days and the oil level is full.

there is what appears to be a round relay that constantly clicks about every two seconds driver side about half way up from the head lamp, was wondering if that is normal, maybe it is the power antenna relay, but it seems someone removed the antenna, so i assume if it is the relay for a power antenna it should be safe to unplug it.

here are some pics of what i am looking at, https://www.dropbox.com/sh/v7uomkq4v91tiou/zGyy5P-ISo.

 

the h23 had the map sensor on the firewall with a vacuum line running to a special port on the throttlebody. newer h22's had the map sensor located directly on the TB. it sounds to me like it has a newer throttlebody on it, and the map sensor on that should not be plugged in and is there just to plug the port, while the one on the firewall is being used properly because that's where the harness plug for the map sensor is located. sounds like the map sensor setup is perfectly fine, as long as the wiring is not currently shorting out. oem map sensors are nearly indestructible, so I wouldn't worry about them as long as the one on the firewall is actually plugged in. if you get a trouble code for map sensor, its most likely due to faulty wiring.

the oil light flashing is not a good sign, it means it detected low oil pressure, which would only be due to internal engine damage, or missing parts inside the motor. sometimes it can just be a bad oil pressure sensor, but that is rarely the case.

you did say you got a cel, which is actually a good sign because it means you can diagnose whatever problem[s] it has. you need to retrieve the stored trouble codes...
look up under the dash right by the edge of the trim for a 2-wire blue plug stuck in a blue rubber boot, should be located on the passenger side just behind the radio, or maybe on the drivers side just behind the radio. it should be right there, not buried deep or anything, so it should stand out when you see it.
when you find it, turn the ignition on (not starting the engine, just key on so dash lights light up). stick a paperclip in both terminals of that blue connector to jump them together. this will make the CEL in the dash blink out the trouble codes. long flashes are first digit, short flashes are second digit, it will pause between codes, there may be more than one code. it will repeat the sequence constantly until you remove the paperclip.

when you retrieve the codes, report back with your findings

 

slight problem, the only plug i could find after calling auto zone was on the passenger side on the strut mount, one blue wire with a two port plug, rubber cap and the wire is broken off.

i know i could fix it, but there is only one wire so not sure if that is it.

 

no that's not it. the service plug is not in the engine bay, it is under the dash. look again, it's there somewhere

 

here is a pic of the location for your exact car:
https://encrypted-tbn3.gstatic.com/i...dwgYfaHWFr-Ldw

I don't know the color of the wires, but the PLUG is blue

 

that is exactly where it was, it gave 2 long flashes then repeated one long and two short so i have a code 12, also i have 2 wires unplugged, including pics.

from what i have found it is 12 - EGR Lift Sensor (Exhaust Gas Recirculation), but not sure what needs to be done.

also oil light flashed again when i was going down the highway, opened it up to 80 - 90 so i think the pump may be weak or i should just service it before the scheduled time.

pics are in my OP link.

i did just find a nice pdf on this site, hope it helps some, also is my prelude a jdm since it was manufactured in japan or is it still usdm?

found a aftermarket, a little cheaper than from

http://www.hondaautomotiveparts.com/...CONTROL+DEVICE

http://www.ebay.com/itm/Honda-Prelud...5a5caf&vxp=mtr

i have read cleaning it might help, someone used wd-40, what would you recommend?

 

your car is still usdm. jdm is Japanese domestic market, which means it was originally sold on the Japanese market, in japan. a jdm prelude would be right hand drive.

typically, long as the egr valve is plugged in and there's not any wiring damage, a code 12 just means the egr valve is sticking or completely stuck, and a good cleaning is really all that's needed to fix it.
take the valve off, push the actual valve up and down with your finger and feel for sticking. it should move easily but have a slight dampened feel to it. proceed with holding the valve open and cleaning as much carbon out from inside the valve as possible, using compressed air. I wouldn't use any chemicals to clean it. maybe some carb cleaner if anything, but nothing else as that will actually promote more and faster carbon buildup in the future. do not use brake cleaner! if you want to use something to help scrape the carbon off, go for it. just try not to scratch anything inside too badly. finish it off with a good blast of compressed air.

 

also, that engine is not an h23. looks like the f23 to me. the engine code is stamped on the block, left side, right next to the hole by the transmission where you check ignition timing.

 

i'll definitely have to look for the code stamp, hopefully it will say f23 or h23 on it, if not i'm sure someone can translate it.

i've cleaned the erg valve a few times before posting again and it seems to help, but i was recommended to use seafoam to clean out all of the carbon and internals, kind of iffy about doing it, but i think i will pick up a can tomorrow when i go to o'reilly auto parts to get performance ngk spark plugs and cables.

unless you think it would be a bad idea as you seem to be a lot more knowledgeable than me.

 

Ok I think I found the stamp on the block.

http://db.tt/X8M9CHE3

F22b1 below it is 1222948 engraved by hand I imagine and above HM.

 

Found this, I'm a little disappointed by the hp loss, but it still could be a good thing and less miles.

http://db.tt/wc56NDtQ

 

I'm wondering why that engine is in a 95 prelude SE?

 

Your not alone in that question...

I did the seafoam, got the oil change, and ngk iridium spark plugs with a mid range set of performance cables.

Runs a lot better now, I'm confused over the 5th cable that came in the set, seems to be a harness of wires where that one should be.

Still some carbon in the engine where it meets the egr, but it's a lot better than it was, and the plugs were looking really shabby like 2 year old never changed shabby.

from what i could find of the stock h23a1 and f22b1, it seems the intake manifold was swapped, but i'm not sure what else has been done and it is frustrating in a way... i wonder if i could either upload better pics or maybe take it somewhere to get it looked over and after looking for a image of the distributor, there should be a spot for that 5th lead, but i didn't notice one.

since i am here and it has been on my mind, under the distributor on what appears to be the transmission, there is a metal tube sticking up and no hose on it, kind of wonder what that is, not to mention the one coming off the top missing a hose as well, think you can see it in a few of the pics.

 

considering you have the wrong motor in that car, and your main issue is driveability and funky running conditions, the main thing to check out is what ecu is installed in the car? because if you have anything besides the proper ecu for that engine, it will definitely run incorrectly.

I don't even know what ecu is the correct one for that engine.

 

It seems to run great now, idle is good, and very responsive pick up.

Whoever chamged it must have used some sense, I just wish I knew everything that had been modded.

I would love to fond a h23ax vtec and kind of go back to a stock motor, everything I have read is a mix of good and decent performance compared to the h23a1 non vtec that should have been there.

So I am already mixed on the engine and since I foumd out it is a weaker engine that is a pain to turbo apparently, I'm looking for a compatible engine equal to or better than the h23a1 with decent miles or a h23ax with vtec.

Also found I have the same issue as most with the valve cover and distributor leaking oil.

So I suppose when I get up I should find out where the ecu is and get a model or serial number and start searching it out.

 

the ecu is under the carpet in the passenger kickpanel, right where the passenger's feet would rest, under a silver plate bracket.