WEll, I just finished putting a d16z6 into my crx and now I am having hesitation/no power problems. Sometimes I also get the bucking problems.

I have converted to obd1 and all of the wiring is correct. It actually runs really good when it is not under load and when it is cool (I think). Also, when I get above 3500-4000rpm, it comes alive and pulls like it should.

I just went through and cleaned the iacv and cleaned the fitv and cranked down the white thing inside as far as I could. I guess one of them could be nonfunctional still, but I don't know.

Does anyone have any other suggestions for this problem? I don't think it is the O2 sensor either, but I will test it tonight.

Any help would be greatly appreciated.

 

does the car throw any CEL? inspect spark plugs and wires and firing order. when was last time u replace fuel filter?

 

no cel now. I had a coade for the iacv, but that was because I unplugged it while fixing the idle surge (it still surges sometimes too). I also had a cyp sensor code, but I replaced the dizzy and now I have no codes.

The firing order is correct: from the lower left going counter clockwise 1-2-4-3.

I checked the plugs and teh wires are good, but I will check the plugs again.

I JUST replaced the fuel filter with the engine swap. I doubt more than a couple gallons of gas has run through it

 

im having somewhat the same problems u r with my h22 civic..
i have to warm up and have my car running for awhile inorder or it to even go pass 3k, once i hits 4-4.5k its as if everything is fine.. i cant firgure it out... now im guessing its thermostat housing... i have no idea..

 

well, I have to assume that it is some sort of vacuum leak in my case. It could be the fitv or the iacv. I am going to try to block off the ports in the throttle body and see if it helps.

 

I have the exact same issue on my d16y8 swaped 97 cx.

I have some codes though as im still fixing the wiring from the previous owner.

Now power below 3k, over 3k comes alive, mine wants stall when cold and idle to 1200rpm when hot.

No vacuum leaks that i can see. Going to try replacing the iacv and make sure he didnt cross the wires when he did the swap.

Edit: Did you check the tps?

 

I have not checked the TPS, does anyone know what the correct test procedure is for it?

I did notice that the TPS on my throttle body is adjustable, but I thought most honda TPS are just fixed mounted. I think that will be the next thing to check.

Let me know how it goes with a new IACV. I had a spare one at my disposal that I put on and it didn't seem to fix anything.

 

I calibrated the TPS to be .5 v at closed throttle and it didn;t run good.

Then I recalibrated it to .45v at closed throttle. It runs better, but still seems to be low on power and hesitate below 3500 rpms.

It also backfires a little at times, but not very often now.

I pulled the plugs and they were white like a lean running engine. I guess I must still have a vacuum leak, or a fuel problem. I guess it also could be poor timing even. I set the timing with my non-adjustable timing light so that the middle of the 3 marks lined up with the timing mark.

Also, when warmed up, it seems like there is a tiny bit of vacuum through the fitv port on the throttle body. should it be completely sealed when warmed up? However, I taped off the port for the fitv on the throttle body and it didn't seem to make any difference.

Any help would be truly appreciated.

 

It sounds to me like you guys are having issues with stuck open EGR valves. This would explain the stalling/surging/running like **** in the lower rpms, and the running well in the higher rpms when the EGR is supposed to be open anyway. Just some food for thought.

 

Don't know about you but mine doesn't have an egr.

Mine still does the exact same things as yours as well.

Im going to disconect the iac and sent the idle manually, set the tps, timing, clean everything and reset the ecu.

 

the original post made by s1267712 is in regards to a z6, which does have an EGR, your motor is a Y8, which I'm not sure about but I think they should have an EGR as well. Anyway, Hope I can help someone.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ESporer &raquo;</TD></TR><TR><TD CLASS="quote">the original post made by s1267712 is in regards to a z6, which does have an EGR, your motor is a Y8, which I'm not sure about but I think they should have an EGR as well. Anyway, Hope I can help someone.</TD></TR></TABLE>

There is no Exhaust Gas Recirculation on a Z6.

Sounds like the problem is caused by a faulty O2 sensor or possibly a timing issue.

OP: If you floor the gas does the hesitation go away?

 

wide open throttle does not fix the problem.

No egr on my d16z6.

Does anyone have the proper procedure for checking the o2 sensor? I guess mine could be faulty.

anyone know why most of the poor idle/poor running conditions I read about go away above 3500rpm? I believe the ecu switches modes from open loop to closed loop, or vice vera, but does anyone know what that really means? Does the ecu stop responding to certain sensors?

 

it could be the timing perhaps....

 

I set the timing so that the middle of the 3 marks on teh crank pulley lined up with the timing mark. I also had the service connecter jumped. However, I will check it again in the morning.

 

The o2 sensor should be checked with a voltmeter. It should produce at most 200 millivolts if not less on the low end, and at least 800 millivolts if not more on the top end. Any less than these numbers is a bad sensor.

What is meant by open loop/closed loop is this: In open loop the computer ignores the signal from the o2 sensor and supplies a rich mix to the motor. In closed loop it references the o2 to adapt fuel trim. The only input that decides open/closed loop is the ECT (engine coolant temp.) Hope this clarifies.