So i got my d16 running finally and somethin really weird is goin on. First i have vitara pistons and eagle rods in it. When i start it with everything hooked up and all it runs at like 3000rpm continuously. Then if you give it gas it acts like its leaning out. So i started just messin round with stuff and i pulled the vacuum hose off the map sensor and the idle dropped and i can give it gas now. if i start it without the map hooked up it runs really weird though. i have to have the map hooked up then unhook it and itll straighten out and run. Nobody i know has any idea what might be causin this and i already tried a new map. I need ideas.....FAST. please help!!!! thanks

 

Tune
IACV

Other mods?

 

uuummm....hhmmm no.....oh i do need a new o2 but it shouldnt make it do funky stuff like that though should it? if ur iacv isnt workin will that make the temp gauge not work too?

 

stock map sensor?
(higher bar map sensor on a stock ECU will do this)

 

What's the signal voltage from the MAP sensor at the closest to idle you can get?

 

It is a stock map....and which wire would i get the votage on?

 

TPS and MAP plugs switched will also do this.

 

My tps and map plugs are in the right place....if i could find out what wire is needed to find the voltage on the map that would probably prove to be the problem.

 

The signal wire is the wire in the middle of the MAP sensor connector. Let the motor try to idle, set the meter to 20v DC, wedge the black probe into the battery negative post and spear the MAP sensor signal wire with the red probe. This will tell you how much vacuum you are generating inside the IM. Please post the wire colors for the MAP sensor, TPS, IAT sensor and IACV and I'm sure the people here will tell you if they are all hooked up correctly.

 

Alot of these sensors work the same way, with a 5v reference voltage, a ground and a signal output. Just so you know, you can have these connectors switched and still have the correct output signal, it would just be received by the wrong pin on the ECU.

 

Ok i think i can do that at school tomorrow....iat is intake air temperature correct?

 

Yep. It's the same connector as the 2-wire IACV so they get mixed up sometimes.

 

i thought one was green and one was clear or white or somethin like that

 

The vtec solenoid connector is green. The connectors that could be switched are the 3-wire ones of the TPS and and MAP sensor, and the 2-wire connectors of the IAT sensor & the IACV. They should all be grey I believe and they are all located on or around the IM.

 

ok....uumm would it change anything if i told you it was a d16a6?

 

Oh, sorry. I'm not familiar with any green connectors for those sensors. However, I don't pretend to know all of Honda's connector colors. If your car has a green or white connector, there are probably only two possible sensors for it to go to. It's the wire colors and where they lead that matter the most anyway.

 

It might help save you some time to know what to look for with the MAP sensor. Healthy motors idling at around 800 rpm read somewhere between .4v and .6v at the MAP sensor signal wire. We're expecting something higher with your motor, meaning more airflow and less vacuum. Then, you'll have to go around the IM closing off vacuum ports (including the FITV if you have one) until plugging one brings the MAP sensor reading back to normal and fixes the idle. Plugging the leak could cause the motor to stall at first since the ECU is currently trying to compensate for the problem.

 

take pics and post them show us the harness and connectors and where they comin from

 

so i checked the middle wire on the map with the car running and it didnt read any voltage. are you sure the signal wire is the middle wire?

 

scratch that....we found the signal wire and at 3000rpm it was getting 1.27 volts. i believe. the iacv is connected correctly. would an o2 be able to do this?

 

You're not making nearly enough vacuum. Air is getting into the IM around the TB. This could be from an idle valve letting too much air in, a leaking gasket or a bad vacuum line. Start looking for the leak. GL

 

As is being discussed in another thread right now, you can use sprays like carb cleaner to check intake gaskets. When you spray it on a leaking gasket, the gasket will usually soak up the fluid and the leak will be temporarily plugged, briefly helping the idle. There's also a chance that the MAP sensor isn't working correctly, so if you check everything and find no leak, you might try replacing the sensor.

 

alright ill make sure everything is all good in that aspect....oh im also guzzling fuel.....i go through half a tank like every day. im kinda thinkin i need a tune mostly.

 

i had the same problem, the leak will most likely be you intake manifold gasket. i received the wrong one in my gasket set before and didn't pay no attention then i wondered why my idle was at like 2500rpms and here my tuner took brakeclean like stated earlier and found the leak.

i'm no tuner, but i highly doubt a tune could make you car idle extemely high like that. and you say you unplug the "map"sensor and it quits. how does it still continue to run, when i unplug my map sensor it shuts my engine down

 

Terrible mileage is a common symptom of a vacuum leak. You'll often have more problems when you press the gas because with a vacuum leak your ECU can't accurately calculate air pressure, so it doesn't know how to make the correct fuel adjustments when the TPS signal changes. The tuning is definately not your biggest problem. That said, quality tuning almost always helps things run more smoothly.