Okay guys, start the car dead cold, cranks and starts fine, as soon as rpms begin to close loop and idle down it starts running rough until it dies shortly after. If you hold throttle it will stay running, no codes in system, checked over the normal diag procedures of the iac, fast idle, Tps, map, fuel pressure, crank sensor, egr you name it and can't figure it out! Any ideas or something I'm missing? Car runs great other wise and even when it's warm it still stalls out when clutch is depressed. If car stalls and you let it sit for a few minutes and start it, it will idle low and stay running without any input but as soon as you hit the throttle it comes back down in rpms and stalls out and will not start without assist of throttle.

 

any ideas??

 

replace the o2 sensor with a Denso unit

 

primary sensor or secondary near cat

 

I would check the read outs from your sensors before replacing a all of that stuff. Most scanners will tell you what the readouts are from the O2 Sensors. I would double check the timing on the engine as well.

 

timing is good, had everything apart, checked that and the crank sensor,
i have a scanner hooked up and checked pretty much every value and
everything is in spec, last resort is the ecu possibly being bad but before i did that i wanted to see if anyone had any ideas i haven't tried

 

unplug oxygen sensor connector if it runs better replace the sensor ... clean out iacv outer filter

 

I would pull off the IACV and clean it, and clean the Throttle body out well, and check the cable adjustment to ensure nothing is sticking at any point.

How old are your plugs, wires, cap and rotor?

 

PLUGS A FEW WEEKS OLD, WIRES CAP AND ROTOR OLDER BUT ALL IN GOOD WORKING CONDITION, PICKED THIS CAR UP TO FIX AND SELL AND THOUGHT THE SAME THING MOST PPL WOULD WITH A STALLING ISSUE BEING SOMETHING SIMPLE AND WHAT DO YOU KNOW LOL, im actually a Honda service advisor and being at a dealer you would think I have the best connection to getting this thing fixed! stumped a few ppl but im going to try to unplug the sensor and see if that helps, already cleaned iac and throttle body.

 

okay update, thought the pcm could be an issue, swapped it out and no change at all, tried unplugging o2 sensors and car still stalls.

 

test ect sensor should be 2000-2500 ohms cold 180-250 when engine warmed up

 

ect sensor shows correct temp on data list on scanner 176 + at operating temp. basicly when you start the car it seems to fluctuate for about a minute from 1500-2500 rpm's and anything below about 1200 rpm's it misfires, after that minute it struggles to stay running and just stalls.

 

if you hold on the throttle it will run and drive but anytime it gets below 1000 it will not idle or stay running.

 

once it stalls you can crank and crank and it will not start unless you press the throttle or wait until its cold again.

 

no check engine light either, nothing in history, nothing stored.

 

replaced plugs as well, plugs after the first couple starts are BLACK! running very rich and exhaust smell is very strong.

 

Exact same issue here with my lude brand new ngk recommended plugs, cleaned out faat idle valve and iacv all sensors work fine car wasnt doing it before. Comp tests p1. 195 p2. 150 p3. 195 p4. 180

 

piston rings

 

I was hoping it wasn't that but guess it is.
Ps. Started car this morning and issue isn't there anymore still tiny smoke but still all the power there

 

you could do also leakdown test

 

That's true will get that done when I can. Also it used to do the problem when cold not warmed up to operating temp so thats my bad. But it doesnt do the same issue anymore

 

It's the coolant temp sensor I'll bet money

 

It's the coolant temp sensor bet you a100 bucks

 

COOLANT TEMP SENSOR I HAD A HONDA CIVIC DO THE EXACT SAME STUFF CHANGED THE COOLANT TEMP SENSOR AND BOOM FIXED

 

COOLANT TEMP SENSOR BET MONEY