SoFresh1189

ok so ive got a rebuilt 95 D16z6 in my 97 civic dx. it wont rev over 2500 idk why. ive got the OBD2 to 1 jumper harness, ive got an OBD1 ecu, ive done the CKF bypass trick, still wont rev over 2500, it acts like its hitting a rev limiter. i also noticed that at idle(900-1100rpm) the oil pressure is about 40 and when i rev the motor to about 2k rpm the oil pressure goes up to about 100psi. it also has higher oil pressure when its running cold, goes down when it warms up.

now, as far as i know all OBD1 motors do not have a crank position sensor. so with the obd1 ecu it shouldnt be looking for it right?

a buddy of mine says using the OBD2 map sensor and tps could do it but i really dont believe that.

also just for ***** and giggles i ran a wire from the crank sensor on the distributor to the crank sensor wire on the ECU plug and the tach read that it was idling at 5k rpm and revved up to 7k where the rev limiter should be. could the ecu be reading it like that for some reason and thats why itll only go to 2500?

eghatch9295

iTrader: (1)

codes?

SoFresh1189

2 of the codes only came on while the car was running...

P1509 - This code came on while the car was off
Manf Cntrl Veh Spd
Idle Speed Control
Auxilary Inputs

P0335
Crank Position
Sensor A Circuit
Malfunction

P0135
O2 Sensor.. easy fix. not worried about this one.

also didnt mention the car runs extremely rich (according to my narrowband a/f gauge). ive had the fuel pressure in the 20s and the gauge still read rich (i normally keep it at 45-50psi)

and before you ask, stock injectors, stock obd1 ecu.

SoFresh1189

actually now that i think of it the o2 sensor could be why its running rich but still wouldnt cause it to cut out at 2500

eghatch9295

iTrader: (1)

fix your codes and report back. sounds like your ecu is in limp mode. crank sensor going bad will make your car run like crap

honda_luvr_2000

I have a question... Why did you do the CKF sensor bypass?
You have an OBD1 computer that won't even be looking for the CKF sensor. And YES all OBD1 engines have a crank position sensor. They do NOT have a CranKshaft speed Fluctuation (CKF) sensor.
If you're setting a Crank Position sensor DTC then yes you will have major engine performance problems.
You are correct, an OBD1 ECU will not notice the difference between OBD1 & OBD2 MAP sensors & TPS. (I'm currently running an OBD1 ECU and OBD2 MAP & TPS)
Your oil pressures sound high. Have you shimmed the pressure relieve valve spring? Are you using a higher viscosity oil than recommended?
Honda spec is- warm engine: at idle- 10psi minimum; at 3000RPM- 50psi minimum. I'm aware that each spec is followed by "minimum", but having done oil pressure tests in the past, it's actually supposed to be from minimum spec to no more than a few psi above the minimum spec.

SoFresh1189

i did the CKF bypass for 2 reasons

1. when i do go to get inspected, ill need the obd2 ecu, in which case i will need to do the bypass

2. idk why but when i did the paperclip trick the CEL gave me codes 14, 41, 3, and 4. one of those is the crank sensor. it shouldnt be throwing that code as far as i kno

and what exactly is limp mode?

SoFresh1189

also the car doesnt start with the key. idk why.

reactone

You say that you're running an OBD-1 ECU, but the codes that you are giving us are OBD2 codes? Now, granted I have no experience in OBD2 to OBD1 conversion harnesses, but shouldn't the codes now be just numbers, like code 17, code 22 etc?? I'm just wondering.

SoFresh1189

Just to clarify, the "Pxxxx" codes were from the obd2 ecu, and the other codes(14,41,3,4) were from the obd1 paper clip trick. one of those codes is for the map sensor, disregard that code, that only came on because we were unplugging it while the car was running.

SoFresh1189

ttt

apexi_rsx

you need to change the lower timing gear to a y7 or y8. then put a y8 or y7 oil pump/pick up and pan on it and then you can run a crank positioning sensor which mounts on the oil pump. sometimes this bypass has been known to throw codes anyway and will cause this problem. if you run a obd1 ecu the problem may go away. make sure your running the right distributor which is either the y8 or z6 dizzy. y8 fits u just need to ream the slot out alil bit and only the top bolt lines up but this make sit so you dont need a obd1-obd2 dizzy conversion harness.... oil pressure is supossed to be high when cold (60-80psi) then when warmed up it goes down to (20-10psi) warm. im also hoping you did a 3wire to 2 wire IACV conversion because a p28 is 2 wire and your y7 originally was a 3 wire iacv...

92bseries

sounds like ur tps wont open ur throttle all the way, i had a hatch wit a b16 and the tps wouldnt let me go past 2k. til i bought a tb with all sensors in tact and it drove beautifully after that

EJeff8

Limp mode is just when your ecu cuts all power and only gives the car enough to "limp" home. If the ecu isn't receiving info about the crank (one of the most important damn pieces of an engine) your ecu is gonna **** bricks and immediately cut power to save what the ecu thinks is left of the engine. There yah go.

SoFresh1189

Yes, I did do the 3-wire to 2-wire IACV fix, the distributor is an OBD1, i bought it brand new and i didnt know they made dizzy harnesses so i cut and spliced the wires together. According to the OBD2->1 dizzy diagram the wiring is correct. Ive checked it and had it checked a million times, if it was wrong it wouldnt run at all. and i would really like to not have to put an obd2 oil pump on it but if thats what it comes down to ill have to do that but thats my last resort option.

also i took the thermostat out because it had some overheating problems and now it runs cold almost all the time. maybe thats why the oil pressure is so high? im kinda afraid of when i do get it running past 2500 how high the oil pressure will be, i dont think its good for it to be that high.

i will try replacing the tps sensor, but if it was bad wouldnt there be a code for it?

and id also like to try another ecu but its kinda hard to get my hands on one. its also hard to believe both my OBD2 and 1 ecu are bad.

reactone

Theres a few connectors that are identical in shape, i don't remember which ones they are off the top of my head, but these could be reversed. If its the map and the iacv that are the same, then that may be the problem considering you have codes for both of them.

SoFresh1189

the map sensor only came up once and that was because it was unplugged while the motor was running

SoFresh1189

so i tried replacing the throttle body completely, had a spare layin around, dont know what motor it came off(i think a y7, not sure) and it actually ran worse.

SoFresh1189

anything else i could try?

SoFresh1189

actually now that i think of it code 4 is the crank position sensor which should be the one in the distributor.. could this mean i have a bad distributor??? it still has to be putting out some sort of signal tho or else the car wont start at all