hi everyone, i would just like to know if disconnecting the cold start injector on my 92 4runner is ok, our climate here is tropical so i dont need that for cold starts ... would it create starting problems?.or leaking fuel?... my fuel mileage is bad so i think it could be a reason..

 

The climate you live in has nothing to do with it. When cold your engine needs a little extra fuel to start, so disconecting the cold start injector will gain you nothing but cold start problems.

If your mileage is bad, when was the last time your 4Runner had a complete tune up ?, plugs, wires, cap, rotor, fuel filter, air filter. Another thing to check is the 02 sensor, if its original or has over 60 thousand miles on it then it needs to be replaced. A bad 02 sensor can greatly effect your gas mileage.

 

i disconnected the cold start injector connector and the car starts even when the engine is cold, im from the philippines,.. our weather here doesnt drop to freezing or unlike if im in canada or where there is winter. where the cold start injector is really needed for cold starts.. thanks for the tip though, just acquired the car all the way from california and looking forward for a tuneup and improve my mileage... thanks..

 

I have mine disconnected. I did so because I noticed my truck was running very rich on start-up, and was thinking that the cold start injector was leaking. With it unplugged, no more running rich.

I plan to replace it before it cools down here for the winter, as even in triple digits right now (Dallas, Tx) I can tell it takes a bit longer cranking to get a cold start.

 

The cold start injector will not effect your mileage in any way. Any vehicle runs rich when its first started cold and as it warms up and gets to operating temp the computer goes into closed loop and moniters the air fuel ratio

Like I said before, check the 02 sensor it will effect engine performance and gas mileage more than anything else. Its one of the most over looked parts on a toyota that never gets replaced when it should. If your 02 sensor is original or has over 60 thousand miles on it, then its bad

 

yes but a leaking one dumping more fuel into the motor will cause an even richer condition.

I'm not saying you shouldn't keep the cold start injector, I'm just saying a malfunctioning one can be disconnected until you feel like dropping the 200 bucks on a new one.

 

that is also what i have in mind that the cold start injector sucks additional fuel for starting during cold starts, as a result can reduce my fuel and mileage.. just trying to save money by reducing the fuel intake.. tnx .. i will also take a look on the 02 sensor..

 

The cold start injector should only squirt fuel when you have the key turned to the "START" position, as in cranking the engine. Once the key goes to "RUN", the engine starts and you release the key, the injector should not be squirting any fuel. It is the "Cold START Injector", not "Cold RUN Injector".

The ECU triggers the fuel injectors at a small, fixed, pulse width (duration) when cranking, so the CSI helps with cold starts. Once the engine starts and the ECU gets a usable signal from the AFM and igniter (RPM), the ECU can adjust the injector pulse width to compensate for temperature and does not need the CSI.

I suppose, if it doesn't ever drop below 65F outside, the CSI is unnecessary.

 

Yes that is correct .

Anything mechanical can stick in the open or closed position.

With the Cold Start injector line always under fuel pressure the only way to eliminate fuel leak (replace or have rebuilt injector also) is to remove the line and make sure the plug does not leak.

 

Yo, I live in hot Florida. My cold injector didn't work when I first got my Runner. I had RC Engineering clean all injectors including CS injector. Big difference when everything was put back together.

 

^^^ @ paintthetown

Having your main injectors cleaned will make a big difference, though. CSI, aside. When it's hot outside....and I mean hot, and during/after hot soak, fuel becomes more vaporous. It's the reason these older EFI's were equipped with a fuel pressure up switching valve system at the regulator. Vaporous fuel can cause a drop in initial fuel pressure in the rail/s on start up making it more difficult to start the engine. Dirty injectors.....again, CSI aside.....only exacerbate the condition.

I've had a broken CSI timing switch on my wife's 3vze for some time now. Hence the CSI system is not functioning. I know because the CSI injector emits no fuel under cold start conditions. Nevertheless, it's never problem starting until it actually gets real cold outside. Even then, it just takes a few tries of cranking in short intervals until the motor will fire. By then, the combustion chambers have heated up a bit from simply cranking the motor over. IF it won't start doing this, I just ground the CSI injector with a lead wire to battery. Fires right up.

 

thanks for the infos, since i disconncted the connector for the cold start injector last week, i didn't experienced any cold start problems even in the early morning or a cold rainy night, the engine starts as if the CSI is plugged.. i also cleaned my injectors with a fuel injector cleaner, i noticed my fuel not run out as fast as before and my mileage slightly increased.. so far so good..