I think it is time to change the fuel injector;

I have recently changed spark plugs and air filter, since then I have noticed the ignition/self is taking bit way too long to start the engine, and eventually when the engine starts, a thick black smoke comes out of the exhausts for at least 10 seconds. Although, there after, i dont see any smoke, even on acceleration in neutral or in gear.

My firend who installed the air filter and spark plugs recommends that the fuel injector may needs replacing.

By the way; The air filter which i got replaced was clotted with accumulated oil and sand (car being in middle east). Could it be that the fuel injector has been affected due to insufficient air intake/flow through the filter ? Is this even releated ?

So my questions are;

1) Does the fuel injector needs replacing ?
2) If so, which fuel injector to change with ? AC DELCO or custom/performance ?
3) If performance, please recommend a brand/type of fuel injector.

NOTE: It is killing me to see the smoke every time i start the engine. It is almost like a mini stroke on my heart. Your earliest advice will be very much appreciated. Thanks yall.

CRABY and SOCOM, your input will be a great help.

 

Have you done a fuel pressure test? I would suspect the regulator is bad. You have 8 fuel injectors. You should call around to some shops, Here in the states you can get your injectors cleaned and flow tested for a lot less then replacing them. This is a common process done to non-US cars also.

You are right to try and fix this as soon as possible, Your not doing your catalytic converter any good.

 

Havn't got the fuel pressure checked yet. Will get this done asap.

I did check with few shops, they are charging $80 to clean the fuel injectors. Although, New AC Delco injectors off ebay/other auto parts websites, will set me for approx $200.... which is absolutely peanuts as compared to here in Bahrain. 8 AC Delco injectors are costing me $450. Ridciculous difference it is.

Will get the injectors cleaned first and see if it makes a difference. I believe it would/should.

Though, I am still tempted to replace injectors with new, in near future. Any recommendation, which performance injectors would suit ?

 

so long as they are flow tested then brand is not an issue. you should also check your 02 sensors to see if they are fouled.

 

Good point Craby, Once the black smoke issue is worked out I would replace the O2 sensor. They are getting gummed up everytime you see the black smoke.

Make sure you get the injectors bench tested not just cleaned. Many garages offer a in car cleaning process which will clean them but they will have no idea if the injectors are working right. Flow testing will check the spary pattern and check for the inject dripping when closed. "IF" the black smoke is being cause by injectors I would guess the injector is dripping when closed. The fuel is pooling on the valve in the intake and when you start it motor raw fuel just falls into the cylinder.

FYI unless your planning building a high HP motor your stock injectos are fine. You will see no differents in aftermarket injectors. I would not install aftermarket injectors unless I planned on getting the car dyno tuned.

 

You may have one or more fuel injectors that are dribbling after the engine is shut off.
That will give you a very rich condition when you first start the engine, along with black smoke like you're getting.
A fuel pressure test would be helpful. If you can watch the pressure drop like a stone after shut down, you can suspect the injectors or fuel pressure regulator. But dropping fuel pressure coupled with a rich start, suspect the injectors.
The O2 sensors wouldn't have any bearing on initial start up with a cold engine, but they may have gotten fouled by now which will affect fuel/air mix once the system goes into closed loop.
EDIT: wasn't trying to parrot Gorn about the injectors, I was already writing my response as he was posting.

 

I may come accross novice; but would appreciate if you can please elaborate on 02 sensors. Cheers mate.

 

This was very informative, thanks. To date, I was not aware of the Flow testing the injectors. I came accross a youtube clip , which I belive details flow testing very well. I know what to look for now.

For now, I am not really looking into bulding on to high HP; as in inital phase I want to get the CAMS in stock/mint shape by replacing anything which has been repaired by cutting corners. I will get the pictures uploaded on this thread, for you all to see what I am talking about.
In second phase, will go for increasing the HP.

 

Nice video, thank you for posting it.

 

The O2 sensors job is to report back to the computer how much Oxygen is in the exhaust. A lot of oxygen means the engine is too lean (not enough fuel). Not enough Oxygen means the engine is to rich (too much fuel) the PCM uses this information to adjust your fuel mixture in real time. The O2 sensor need to warm up before it can work. If the black smoke you are seeing gets a coating of soot on the O2 sensor then it will not read the O2 correctly. It will pass this bad information on to the PCM. If the data is really bad the check engine lite will come on, but if the data is just a little bad it can make the car get bad fuel mileage and lose power.

Cheers