existanzcivicb20

Hello all im in need of some help. I have a 1997 civic and i recently dropped an B18 into it the car runs great when its cold but when the engine gets warms up and i hit the accelerator the engine bogs down and almost dies after a couple of seconds the RPMs shoot up like normal.

And after i turn off the car it will not start back up unless i hold the throttle wide open

Things that i have replaced so far
plugs
injectors
fuel pressure regulator
distributor, cap, rotor

i did test the TPS tested out fine

what else should i look for

also i do have a walbro fuel pump on the car would that cause an issue?

existanzcivicb20

I also posted a video of the issue i am having

https://www.youtube.com/watch?v=52ZP...ature=youtu.be

Civicdx96sedan

Primary o2 sensor maybe

existanzcivicb20

The check engine light does pertain to both O2 sensors heating elements. Can anyone explain to me why the O2 would cause this problem???

existanzcivicb20

Help lol

TomCat39

Had to look up why heated O2 sensor. I couldn't remember what I had read about them.

Essentially the heated ones work sooner which in turn switch the ECU into closed loop sooner thus saving fuel on shorter trips.

I guess the O2 sensor doesn't produce voltage for the ECU to read until it hits approximately 650 degrees. The heated version gets it to this tempurature faster.

In open loop the ECU is running the car rich, which in turn acts as a coolant and keeps the exhaust cooler among other issues with being rich including clogging up the cat over time.

If your O2 sensors aren't working at all then the ECU will keep the mixture rich and all the associated problems that go with it will be present.

Heated O2 sensors came about to extend the life of parts especially on in town short trip type driving.

Hope you find this info helpful.

As for why it would bog down if the O2 sensors were bad once warm.... I can't say I know the theory behind it, but i do recall the old choke systems on the old carbureted cars back in the day. You'd choke it when cold and as the car warmed up if you didn't unchoke it, the car was gutless and didn't run well nearly dying. This sounds a lot like that. Cold it needs it rich, once warm, too much fuel is counter productive. Without the O2 sensors the ECU doesn't cut the fuel back to attempt reaching the 14.7:1 air to fuel ratio.

existanzcivicb20

I will change the Fuel Filter today and will post the results

JoeBlue

What was under the hood before, and is this the same ECU?

existanzcivicb20

A B20 and it ran fine and i have 3 different ECU's and i tried them all and it still does that same thing.

jaytibba

your dizzy is in time?

existanzcivicb20

I have tried messing with it and I even replaced it

marcelosm

But is it in time? In other words have you checked it with a timing light?

ej6-b16

are you getting any cels and if so what are they ?? and i had the same problem and in the end it was the map sensor and iacv hope this helps

existanzcivicb20

only cells is for O2 sensor heating element. also how can i test the map and iacv???

existanzcivicb20

yes timing is on point

existanzcivicb20

Ok so I replaced my fuel filter again and it seems that the bogging got worse... Any Ideas?

TomCat39

What ECU are you running with your B18? And which B18 is it?

RoseFuneral

check the fuel pressure. im having the same type of issue. also check the main relay.
when i am climbing a steep hill, and the engine is under some load, my fuel pump makes a squeaking noise until im at the top of the hill and the load is reduced. also lack of power, jumpy idle, missing, backfiring once in awhile, and a lot of engine breakup sometimes.

also when i shut the engine off after a drive, i can sometimes hear the fuel draining back into the gas tank. which leads me to believe the fuel pressure check valve inside the fuel pump has gone bad.

do a fuel pressure test.

existanzcivicb20

LS with an LS ECU but I also have a GSR ecu and another LS but the car does the same thing with all ECU's

existanzcivicb20

This are my results on the IAT connector WITH THE KEY IN THE ON POSITION.
One lead on the positive post of the batter
Green / Black wire = -13.70Mohms and -12.28V
Red / white = -13.17Mohms and -7.30V
One lead on the negative post of the battery
Green / Black= 33.7 ohms (not mega) and 0.01V
Red / white = open and 4.99V

Any one care to share their input on these results???

TomCat39

Did you try and read the resistance with the power on (key in the on/II position)?

That's really hard on a digital multimeter. The meter uses a battery to supply current to the circuit when testing resistance (ohm readings). With power already to the circuit you are testing, not sure how that's going to react to the power circuit of the ohm part of the meter.

You can't have negative resistance, with the exception of superconductors. And even then I'm not sure if it goes to a negative resistance, just really really low.

existanzcivicb20

the key was in the on position

existanzcivicb20

I think the negative just means I had the leads backwards but the values should be the same

TomCat39

I could be mistaken but I don't believe you are supposed to check resistance with power supplied to the circuit your are testing. At least that how it was when I took electronics, maybe things have changed since then.

existanzcivicb20

I tried changing my walbro fuel pump back to stock and still no change.