Okay for starters, I have a 1989 CRX DX converted over to PGM-FI.
Then the single cam was swapped for a OBD 0 B18a1 out of an 90' Integra RS w/ ecu.

I rebuilt it completely with new seals, gaskets, bearings, oil pump, water pump.... etc. Everything but a head job, which was not leaking any oil what so ever in the donor car. Used conversions mounts by Innovative, and shift linkage from Avid Racing.

Now for the problem. The car starts up fine, everytime you turn the key it fires right up. But when it idles, normally after two to three second, it drops to about 1,200 - 1K rpm. The low oil check light comes on. Checked the oil it was full. Since the first time this happened I have bought a new oil pump and installed it. Same thing. I dented the oil pan just to make sure that the oil feeder is not touching the oil pan. The only thing I have yet to check is the oil pressure sensor itself.

Any comments would be appreciated. And Yes I have searched H-T along with other forums and have not come up with any information.
Please I really need this fix so I can finally state ref my car and do some Auto-X'ing.

 

Check oil pressure sensor then come back

 

You answer your own question.
check oil pressure sensor/lose wires.

 

check the sensor. make sure there is a nice and firm connection. also check to make sure there is no sludge from old oil on the pan, this could be an indication of some possible problems.


what kind of oil are you using, just curious.

 

pm me with what parts you wanna sell of your crx. i need some and wouldnt mind checking it out, im also in sac.

 

Okay, I have changed the oil pressure sensor out for a brand spanking new one. Same thing.

The engine oil I was running use to be SAE Non-detergent 30w for about 10-20 miles. Can't remember the precise mileage. But it was used solely for getting the metal out of my motor from the bearings and piston rings.

Currently I am running 5w30 non-synthetic. I have also checked the wire connecting to the sensor and it seems fine. It fits very tightly on there without any room to move.

But I do have a question. Anyone know what the sensor with two wires running to it, that is located right next to the oil pressure sensor and right underneath the radiator fan prongs? I am unsure of whether that sensor is the knock sensor or not because some people have told me that it is not.

Thanks for the help guys.

Oh and the CRX Si was forcibly taken away from me by my older brother since he just sold his car and needs a commuter. So hes going to restore it to running condition and provide me with parts to fix it for him.

 

-bump- Anyone? Any ideas?

 

shoot your lucky you have that light showing, mine doesnt even do that. so i dont know when my oil is low -_-

 

Pull your oil pan and make sure your pickup screen isnt stopped up. Only takes like 20-30 mins on a civic/CRX

 

Hook up an oil pressure gauge into the same hole as the oil pressure sensor and see what the pressure is. I believe it is supposed to be 60 PSI at idle on a B18

 

Yeah checked the screen. I flushed it with a whole can of brake cleaner to make sure nothing was stuck in there. That was the very first thing we checked before buying and installing a brand new oil pump.

Could it be a bad bearing?

 

Thanks, never thought of doing that. First thing monday, I am going to go buy a oil pressure guage and test it.

But still anyone know the sensor/plug that is to the left of the oil pressure sensor? I have pics but I can't seem to find the usb for my camera. So I can't post it up.
The reason why I'm asking is because I just checked and the plug that is in there is not running to anything. It has wires running to the harness then it is just electrical taped down with the harness. I've cross referenced the Integra's wiring diagram and can't seem to find what it is. But I may be overlooking something.
Any ideas?

 

Fan switch

 

Actually, the fan switch is above it I believe. Because the fan switch is a two pronged sensor like the oil pressure sensor.

But the sensor I am unsure of has a two wired plug running into it. I don't know the color of the wires, which if I did I am sure someone could easily tell me the answer [Not the original LS harness].

I am debating whether it is a knock sensor, which my friends tell me that integras don't come with knock sensors.

 

^^

 

Check the little o-ring on the top of the pickup where it connects to the pump.

 

knock sensors are usually 1 wire, they create their own voltage and send the signal back to the PCM, I'm not sure about teg's but i'm doubting it's a knock sensor

 

it's a fan switch that reads oil temp instead of coolant temp. some teg's had this feature, no civics did that i'm aware of. also, the oil pressure sensor is not a 2 prong, it's a single wire connector on the back of the block.

if we're talking about the same thing then the connector in question is the one currently plugged in in this picture. 2 prong switch to the right reads coolant temp and engages the relay to turn the fan on. the 1 wire sensor controls the oil pressure light in the gauge cluster.

 

You are my hero. Love the picture. And yeah I was wondering what the fan switch that reads oil temp was.
Since that is the case, I will just pull the plug out since it is not wired to anything except electrical tape.
Now I can go have a beer for July 4th with no worries. Happy Independence Day everyone.

 

wait post not yet wait for me so the bottom sensor wit one prong is oil pessure so can i take my wire from my new gauges n jus hook it in2 that splice the wires, and the one above it wit two prongs comin out not the plug to the left but the one right above wit the two prongs can i jus splice and wire my new gauges directly to that and if so the gauge comes with one wire does that mean that the other wire is i guess a ground so leave one and splice other one, very good pic by the way must of had a small camera a phone i guess lol

 

both 2 prong sensors are fan switches. all they do is provide continuity between the 2 points when the preset temperature is hit. you cannot hook any kind of gauge up to these. the 1 prong sensor either provides ground or nothing at all. it's purely for activating the oil pressure light in the gauge cluster. it cannot be made to do anything else. you need to install an oil pressure sending unit be it electrical or mechanical and run the nylon line (mech) or wires (elec) into the cabin where they plug into your aftermarket oil pressure gauge.

 

so was there a solution to this problem? i bought a JDM DC2R and i got the same low oil light problem below 1k rpm changed to a new oil pump, new sensor and engine was rebuilt so strainer was cleaned

 

Sorry for no update, but I have been busy working full-time and working on my cars every so hour that I have to myself. Been a rough month, but the crx dx is running without check lights and has no more idling problem. It turned out that the bearings ACL sent me were spec'ed wrong even though they told me that the bearings were at 3.29 mm. Which when my micrometers arrived it wasn't. Unfortunately my micrometers came after I had already pieced everything together and fired it up, plus I had bought the bearings like 6 months prior.

But always try to measure your bearings first. That is the major part I skipped on and I payed dearly for it. *cough* noob mistake.

Well since, you have changed the oil pump, sensor and ensure that the strainer has adequate oil feed than the only reason I can think of is a bad bearing. You might want to open it up again and just check that all the bearings are spec'ed right to oem sizes [if you have not bored out your block]. Since it is a jdm motor, which are known to be abused whether being shipped or being driven, you might want to ensure that the water pump is new too. (Not sure if you did it, but it you did )

A good investment would be a micro-polish and balance on the crank to make sure that it is absolutely straight, which sometimes your eyes fail to notice. But either than replacing the bearings I can't really say much. I just went out and bought a new block with good bearings (OEM Honda Bearings) in it and swapped the blocks. Runs so silky smooth now.

And for all I have to say is that with the LS in the Rex, the next season of Autocross you're gonna see a deadly competitor.

 

Check the gasket for the sump, make sure the bolts are tight too, your sending unit in the back of your block, if it goes bad, the light doesnt come on, same as if the wires are disconnected. You might be looking at a spun bearing, worn races or a booger'd up sump

 

i hope its just the bearing and not the block... im sending it to a proper workshop this time and hope its just the bearing and nothing worse