I have a 96 cx hatch with a b17 swap (b16 head and pistons)

I notice when ever my gas is low my car idles low, like 700-750rpm, someitmes 550-600 .. but it stays steady where ever it's at.

i used to run 87 and it idled low all the time, now i run 93 and it only idles low when my gas is low. If i have a quarter tank or higher, my idle is about 900rpm

what could this be ?? Normal ?? Let me know what ever else information you need.

 

You might need a tune up. Maybe a clogged fuel line. You might want to make sure its not leaking oil too.

 

Clean the iacv with carb cleaner.

When was the plugs, wires, dizzy cap and rotor last changed?

Fuel filter replacement and a fuel system cleaner wouldn't hurt it.

 

-It was leaking a little bit from the cam seal, but I replaced it with a golden eagle one and the leak is gone
-plugs are brand new, wires look good, dizzy cap is old tho .. A tune up wouldn't hurt at all, I should definitely get a new fuel filter and clean out the system. That's probably what it is ..

 

I cleaned the iacv a long time ago btw, must be the fuel system .. shell sat for 2 months before the swap went in

 

was it idling the same along time ago?

 

timing will change idle

worn out fuel pump might be issue
fuel pump is cooled by fuel if you are low the pump heats up more and might not be working as efficient dropping the fuel pressure

try a fuel pressure gauge to see if pressure drops when low on fuel

and also check if your fuel gauge is working properly

doesnt ecu adjust timing for different grades of gasoline if used improperly?
vtec engines should always be ran on premium

 

fuel volume is another thing to consider also

 

-Yea the swap always idled low ever since I first put it in, I'm running a chipped p28 threw a jumper harness to obd1 at the moment, but I did have a 2000 EX ecu a long time ago and it idled good but that was only for like an hour the ecu wasn't mine ...

-Just discovered last night that I have a bad radiator as well ...

-what fuel system cleaner do you guys recommend ?

-I was also looking to buy a fuel pressure gauge very soon, money is tight due to Christmas season an gifts but I'm trying to get on top of things

 

shell and chevron already have enough system cleaners

you can add isoheet if you think theres some moisture in your gas tank..

and what bin file you running?

you have to get it tuned properly even with that combination because its not b16 b18 or b17 stock so either of those stock maps will still be off especially on idle.

look at the rpm/mbar values they are different for each one and also the idle setting in crome is different for each one. i know gsr idles a bit higher than b16 on stock crome maps have you messed with idle adjusting screw at all?

 

-Yea I've messed with the idler screw a whole bunch, nothing changed, even when I mess with the distributor a little bit, nothing changes, I have nooo idea.. yea I run shell v-power anyways ..

-Right now I'm not 100% sure what base map it's set to but I do know that it's a stock injector basemap, I think skunk 2 .. If I don't recall wrong.

-Also, it is not crome, it is "Hand command" idk if you guys have ever heard of that..

 

you should mess with it idle screw only when iacv is disabled
when in diagnostic mode you wait till its normal temperature( after rad fan turns off)

then check the timing

check the idle and adjust if not correct with idle screw
then check the timing again because it will move
in other words sync the idle speed with timing

 

-Yea when I saw the idle didn't change at all messing with the screw I just put it back to where it was

-And I adjusted timing with a timing light as well, when I first put the swap in but I should probably do that again since I was messing with the dizzy and it's probably not exactly where it was before..

-I'm gunna start by getting a new fuel filter, new dizzy cap an rotor, new wires, and re timing it. Maybe even another ecu, because I think that's the real problem .. I'll get a street tune when possible

-The bad radiator could be affecting my idle right ? Since it's leaking it's not holding any pressure. I always make sure to top off the reservoir, so I haven't over heated at all .. But I definitely need one, I find myself topping the reservoir off almost everytime I use the car (which isn't everyday)

 

it sounds like to me you are about to shoot gun your problem instead of just dianoseing it witch if you have the money to just throw parts at it till you fix it cool if not i would start with the radiator then test fuel pump and pressure test your lines and your tank also a fuel injector balance test might not hurt where did you get you swap from do have a good rep just sayin run a few test fix what you know needs fixed before spending money on parts you might not need

 

iv done the whole "buy parts till it fixes it, listen to stephen.

 

why the hell would you run 87 octane on a vtec engine.

you probably damaged some parts from detonation

a picture of an engine bay also helps to see if theres something obvious mechanical issue

 

** UPDATE **
-Radiator was changed today
-Also discovered an injector was leaking slightly.. I replaced the o-ring, it was squished for some reason
-I didn't run 87 on purpose ! It was just left over gas from when I had the single cam in
-Tomorrow spark plug wires and dizzy cap an rotor will be changed, since I need it anyways, OEM parts will be used.
-ALSO discovered the dizzy cap I was using was off a single cam non-V .. distributor is b16 tho

 

These things are all fine ... I built the swap myself, everything was done super legit with machining. Anywho, I totally agree with you, that's why I decided to start with just the radiator.