Low RPM/acceleration/idle issues (video)

Ryanabn82

New Member
Hello club civic,
The car is a 2000 civic lx sedan auto mods are I.H...its awaiting a nice fresh motor but seems to be falling apart little by little, first the trunk leak, then door leak, head leak (still sealed surprisingly) cleaning up rigged wiring etc. I cannot pinpoint when but about two weeks ago I experienced my first idle surge..it wasn't your typical surge. When started cold had a perfect idle, tone, overall healthy vibe to it. Then, 0nce warmed up - gradually ill see the rpms rise and fall until its full blown surging and I'm having to half way smash on it every time I take off from a stop to keep it from bogging down.. once I pass maybe 2500+ rpms its completely fine. stop put it in P or N and rpm raises then begins surging again...so after plentiful research and $$ spent. here's what I've already done to try and fix this:
1. All hoses checked and besides some weird routing no leaks
2. 2 PCV valve replacements
3. new fuel filter
4. new evap purge shut off valve
5. coolant temp sensor with thermostat
6. IACV clean
7. IACV replacement
8. TB clean
9. Several adjustments on TB and accelerator cable
- I know..
10.transmission flush
11. coolant burping (maybe not to standard)
12. several idle relearn attempts (all rushed..)
13. new battery (bad cell)
14. new alternator(tested bad
15. 2x valve cover gasket with spark plugs + wires (ngk) replacement
16. countless useless additives
17. intake manifold gasket

after some research i'm 90% sure i need to redo the idle screw on my TB/ idle relearn...what else could it be?

Video: driving down city street about 35mph. Barely touching gas to show what happens I don't normally drive like that ha

https://drive.google.com/open?id=0B_tp2U9nn0KwaVlRRGpvR1VqRk0
 

XpL0d3r

I had a Civic once.
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Is the CEL on?

I had a very identical issue with the bogging down. I ended up being the primary o2 sensor. It was functioning but screwy, I'm guessing sending weird signals to the ECU. Car worked fine when the engine was cold because the car does not use O2 sensor feedback until the car reaches operating temp. Oddly, once I got to around 3k it started behaving normally. I had no CEL. Not saying this is your issue (I never had a lumpy idle), but it might be something to look into for sure.
 


Ryanabn82

New Member
Is the CEL on?

I had a very identical issue with the bogging down. I ended up being the primary o2 sensor. It was functioning but screwy, I'm guessing sending weird signals to the ECU. Car worked fine when the engine was cold because the car does not use O2 sensor feedback until the car reaches operating temp. Oddly, once I got to around 3k it started behaving normally. I had no CEL. Not saying this is your issue (I never had a lumpy idle), but it might be something to look into for sure.
Yes, CEL is on. it's been on for 02 sensor that was removed when the header was installed. it left me with two openings one of which I tried to extend the wiring harness to.
 

XpL0d3r

I had a Civic once.
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Yes, CEL is on. it's been on for 02 sensor that was removed when the header was installed. it left me with two openings one of which I tried to extend the wiring harness to.
Tried? So you did or didn't? lol. I have a stronger feeling your issue lies with these sensors. Make sure your primary o2 sensor is pre-cat, and your secondary o2 sensor is post-cat. Make sure the primary 02 sensor is good.
 


Ryanabn82

New Member
Tried? So you did or didn't? lol. I have a stronger feeling your issue lies with these sensors. Make sure your primary o2 sensor is pre-cat, and your secondary o2 sensor is post-cat. Make sure the primary 02 sensor is good.
haha well I did wire something.. I had one built into the cat/header, one at the bottom of exhaust manifold and then one more ? bought this car with ex exhaust piping
 

XpL0d3r

I had a Civic once.
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haha well I did wire something.. I had one built into the cat/header, one at the bottom of exhaust manifold and then one more ? bought this car with ex exhaust piping
Header and exhaust manifold are the same thing. Is the cat built into the manifold? If so you have an LX manifold. If you have a 3rd o2 bung, make sure it's blocked off. As long as you have one o2 sensor pre-cat, and the other on or behind the cat, you will be fine. But make sure the pre-cat o2 sensor is functioning properly.
 


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