Hello,am having a major power loss and bad fuel economy of my b18c4.I notice if i press the gas pedal and hold it at 2000 rpm,the rev will bounce up and down from 1700-2400 rpm..its does this at all rpm range.Do you think this can cause the rich condition.But at idle it remains at 750-800rpm steadily.Need suggestions what might cause this.Thanks.

 

Check that everything inside the distributor has clean and tight connections.

 

I'll check it tomorrow and let you know.

 

When was the last ignition system tune up?

Any CEL codes?

 

Hello...i received my fuel guage yesterday..it reads 38psi at idle and 46 psi at wot.And for the distributor we check all connections and its fine.I've never replaced the distributor cap neither the rotor as it looks fine,it doesn't misfire..engine has 80,000 km mileage.

As for the power loss and rich fueling,it was the valve clearance that was not adjusted properly last time..So we readjust it according to manual..now it feels lively.

But the rpm keeps bouncing up and down when pressing gas pedal at a constant range in neutral...and am out of idea what might cause such.Thanks for suggestions.

 

anyone experienced that?

 

anyone??

 

Check VSS? That's all I got. And you should have replaced the rotor any way.

 

VSS is for speedo

It is going to be something distributor related. There will be a wire that is shorting.

Do you have access to a multimeter?

 

Yes..what would you like me to test,which wire exactly?

 

How about all of them....there aren't very many.
You can find online what the wires are suppose to read. Or a local auto parts store can tell you. I cant remember off the top of my head.

 

Do you mean just the gauge bounces up and down, or do you mean the engine rpms actually fluctuate?

Aftermarket or failed components in the dizzy are usually the cause of tach bounce. Coil, ICM, wiring, or the pickup inside distributor are suspect. Are the distributor components OEM or aftermarket?

Jugger is on the right track. Check the wires going to the ICM inside the distributor. The terminals can get loose and cause weird issues. Just pull each one off one at a time and carefully squeeze the terminals closed a little with needle-nose pliers. Don't overdo it or they will be hard to get back on.

 

Infact the engine revolution fluctuates when holding the gas pedal at a constant rpm.Ok,i'll try another distributor and see how it accelerates.

 

So the idle is lopeing/surging? Sounded like the tach was jumping around, and didnt sound like its rpm dependent. If its is, i would be looking at vacuum leaks and cleaning of the iacv.

 

No,the idle is fine..750-800rpm without jumping...The rpm only fluctuates when i hold the acceleration at 3000rpm or at a certain range...it doesn't stay at that point..it bounces up and down with a 300-500 rpm fluctuation...you can hear the engine tone gets upper and lower...also,the throttle response is sluggish....I want to know exactly if its a vacuum leak or an electrical issue?i believe if it is a vacuum leak it should affect idle?But the idle is so smooth...Its more electronically related as you mentioned.Thanks for your kind response.

 

a slow responding O2 sensor can do that, unplug the O2 sensor and recheck

 

Today i try replacing some sensors with no improvement.Now i must try another distributor and o2 sensor as well.We noticed also that rpm fluctuates only when the engine gets to some temperature when holding gas pedal.

 

Check your fuses too. My buddy had the same problem and he blew his ELD

 

Well today i check for wiring or loose connections,wires are fine...But what i notice is that when i unplug ECT sensor and hold the gas pedal at 3000rpm it doesn't fluctuates.Following this test,i then replace the ect sensor and plug it back,press and hold gas pedal at 3000rpm it still fluctuates.I assume there might some issue with ect wires...We are unable to find it.

 

Does it fluctuate while driving or only while the car is sitting still ???

What ECU are you using ???

 

It does only when its in neutral.Its a b18c4 engine using jdm b18c type r wiring + jdm p73 ecu.

 

When you disconnected the sensor, you threw it into open loop. It doesn't pay any attention to the O2 sensor when in open loop. Just sayin'....

 

You want me to test another o2 sensor?It might be faulty?

 

You can see in the video how exactly my car is doing.

Am experiencing a very bad throttle response,its slow and i assume the fluctuation issue is the cause.

 

anyone have any idea?