I recently swapped a JDM B18C GSR into my 95 ej civic. Everything went great, except for a few little gremlins I've been trying to work out. My biggest problem is the damn thing keeps loosing power in the 2500-4000 rpm range. It seems to sputter, bog, hesitate, or what ever term you choose. This only happens after the car is completely warmed up. I repeat this doesnot happen when the car is cold. Every now and again after a little bit of mildly hard driving I begin to have a slightly different problem. The car begins to jerk. For example: when I just touch the gas pedal the car thrusts forward and when I begin to let off on the pedal, it jerks the car backward. I origionally thought that the timing was off. I checked that and NOPE, Timing is right where it is supposed to be. I have new spark plugs, wires, distributor cap, and rotor. Next I thought that maybe it is the fuel system. I replaced the fuel filter and the injectors. That seemed to fix the problem. That was 3 days ago and today it started up again. It's not the cat, and I don't think that it is the air filter.

PLEASE FOR THE LOVE OF GOD! SOMEBODY HELP ME!!!!! If you don't know the answer, please ask a friend. Anything, I'm extremely desperate. I don't know what else to do.

Thanks in advance for helping an idoit who can't seem to get it together.....

 

check all the vacum hoses it made my car do something similar

 

Did it seem to happen when the car was under load? That is what I noticed with mine. It only seems to have these sputters when the car is under load.

 

Transmission. check it.

 

Is the car throwing any codes??

 

If the problem is happening only when you warm up the motor, and bogging between those RPM's, then your O2 sensor is screwed. Check your wiring, make sure you don't have any CEL's, if no CEL's and wiring is good with the O2 sensor, then replace the O2 sensor.

- WHT/RED wire goes to D14 which is O2 Sensor Input
- ORG/BLK wire goes to A6, which is Heater Control
- GRN/WHT wire goes to D22 which is Sensor Ground
- YEL/BLK wire goes to the power junction harness by the clutch master cylinder, leading to A25 which is Sensor voltage

 

o2 sensor, MAP Sensor or vaccuum leak.

 

It'd be the O2 sensor, or the TPS most likely. if it was the MAP then it would happen thru out the whole time, if it was a vacuum leak, it'd happen all the time.

Since it's happening only when the engine is warm, the ECU doesn't have correct readings from the Heater Control on the O2 sensor.

 

don't forget water temp sensor. it controls the car in base timing, and controls injector pulse. check output of water temp sens. (coolant temp. sending unit)
it's a little 1-wire sensor under the dizzy area. not the fatter one, thats the fan switch.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 22lbGS-R &raquo;</TD></TR><TR><TD CLASS="quote">don't forget water temp sensor. it controls the car in base timing, and controls injector pulse. check output of water temp sens. (coolant temp. sending unit)
it's a little 1-wire sensor under the dizzy area. not the fatter one, thats the fan switch.</TD></TR></TABLE>

Water Temp sensor, ECT and the sending unit. Don't confuse 'em

Good pointers y0

 

hey, i'm tryin. all these damn pop-ups are gonna make me lose my damn mind. i was thinking- it seems like while the car is in closed loop (base timing). when you checked the timing, did you short the smaller 2-wire plug under the dash on the pass. side?
and i believe your timing should be something like 16 +- 2 BTDC. did you time it off the right mark?
i think jOOr timing is farked.

 

it sounds similar to a problem i was having. u said u got new sparkplugs and wires, well the same thing happened to me after i got new wires. u need to check the wires and take them apart and make sure everything is running through correctly, whcih is what i did to find out that i had a defective set of wires.

 

I appreciate the responses guys thanks. Ok, I'm not throw any cel's. Wouldn't the O2 sensor throw a code if it didn't work right? Is there any way to see if it is the O2 sensor without having to go and buy a new one and replace it. I bought my swap from Steve at hmotorsonline.com and he gaurantees that all of his O2 sensore will work. However, I would have to know, for sure, that it was the O2 sensor before I called him.

 

bump
for the afternoon guys

 

Bringing it back up one more time for the evening fella's. I really need help with this.

 

first thing you might want to check is the TPS. borrow/buy a voltmeter and check the voltage from idle to WOT. It should be a smooth increase from .5 to 4.5 at WOT. I think you should check that before you troubleshoot anymore.

 

I had the same problem ended up being the IAC valve... Thus only happening whenits warm.... Hope that helps...

 

I threw IACV codes when my cruise control vac line came off. It wouldn't idle steadily, it would jump up and down in the rpm band. It sounds like the o2 sensor.

 

what exhaust?

 

Well, the ECU's mappings when the engine is cold is very rich to warm the sensors and the coolant up (getting the computer to operate at normal temperatures).

The ecu knows the motor is warmed up properly when the O2 sensor has a correct reading and switches to the normal mappings. If it has wack readings.

I had this problem before as well using my EX harness with the VX shock tower harness. I actually didn't throw the code, but I pulled it and came up code 1 when it didn't throw it. I had the annoying bogging at that specific RPM as well.

Also make sure the TPS is correct readings like said above, WOT at 4.5v and idle .5