I swapped in an OBD1 b18b into my 99 hatch dx.

-I replaced the clutch,timing belt, water pump, plugs and wires

-ECU is the stock LS ECU with the b18b swap

-NO CEL

-On cold start up, car fires up right away at a ~1600rpm and after warmed up it holds steady at ~700-800rpm

-Car will run great for 40-60 minutes....going through all gears and power bands.

-Then for an unknown reason, after going harder through a gear up to like 5-6krpm, when I come back to idle, its a little rough but then I go to hit the gas/partial throttle and it will bog/hesitate big time unless I go to WOT. If I go to WOT , the car will run normal again. Idle will still be a little rough. This happens in any gear, I could be going only 10mph and put in 3rd and hit WOT and it will act normal.

-I already switched out the MAP sensor and the problem still occurs

Any suggestions? I have read a lot of different threads, but they all just fall off with no follow up to what the problem actually was.

 

did you calibrate the map sensor when you replaced it?

 

Just curious, how do calibrate the map sensor?
-After swapping out the map sensor I did fully reset the ECU by disconnecting the battery and pulling the fuse (actually just let it sit overnight that way).

-Then connected it back up in the morning, and started it with no ligths,vents or radio on and let it learn its idle again until the it fully warmed up and the fan kicked on.

- After that I turned it off, then started it back up and went for a drive. Is that enough, or do I need to do something different?

 

Search on how to do it.

you will need a multimeter (5 bucks at HF)

 

So I have been searching and all I come up with is calibrating the TPS and nothing for the MAP sensor...although I do find links talking about calibrating the MAP sensor when using a 3bar and an aftermarket tuning software like Hondata or something. But nothing really for a stock map sensor on a stock ecu?

 

Im sorry, I meant TPS sensor..

try the TPS


Also, have you replaced fuel filter and or fuel pump..?

This almost sounds like a pump with intermittent issues.

 

When it bogs, is it as if it has 0 power, then when you give it gas it just "kicks in" all of a sudden? If so the exact same thing just happened to me 2 months ago, I searched and searched until I finally found a forum where a guy had the same problem and changed his 02 sensor and the problem completely went away, So I changed mine and it hasn't done it since, I'm about 99% sure that's it based on what you have told us.

 

Well, oddly enough I checked the voltages for the TPS and they were within spec but I decided to unplug the TPS and run it like that.

-CEL came on right away, drove it for about 20 minutes...drove without hesitation.

-I then pulled over, turned the car off, plugged the TPS back in and turned it on.

-The CEL went off, but the car's idle was a little rough, put it in 1st gear and started to drive off and it bogged and hesitated right away.

-Turned the car off, unplugged the TPS again and turned it back on. CEL came on but the car drove without hesitation again and idled great.

So go figure, I am going to replace the TPS and hope that fixes everything and that its really not masking another problem.

 

Before my above posts, I did replace the 02 sensor yesterday and that didn't change the way its acting but thanks. As for how it acts, it was basically having zero power at partial throttle all the way up to almost WOT and then at/near WOT, it would kick in.

 

If it always runs perfect with the CEL on, I doubt it's ignitor, coil, spark, or mechanical timing related.

Driving with a CEL makes your ECU stay in open loop mode, ignoring most sensors. (the same way it runs while warming up) And since it runs fine that way, I would guess it's one of the sensors that's ignored that is the problem. Test/replace the TPS, MAP, IAT, cam/crank sensor, etc.

 

That's EXACTLY what mine was doing, I'm surprised that didn't solve it, did you replace it with a new or used one? The odd thing with mine is it didn't even trip a CEL code, but after replacing it the problem completely went away. Doesn't 97 civic's have 2 02 sensors? Just curious if you did both of them.

 

Yea, I bought a new Bosch sensor. I swapped in an OBD1 b18b and I am not running a cat so I only need the one (primary) sensor.

 

Yep same with mine, I can't believe it didn't work though. Well good luck man, hope you figure it out soon, I know how frustrating this stuff is.