Fuel injector or no?

[vegita319]

Ok, i just bought a 90 240sx to replace my wrecked hicas. It currently runs but runs like shit. The guy i bought it from told me it wouldn't pass smog because one of the injectors is running at 50 percent duty cycle. Well people on the forums say its because of leak injectors or bad o rings. I looked around the injector and didn't find any fuel leaks. I also pulled the spark plug with then engine runnign one by one to see if it would bogged and it bogged about the same on all 4 cyclinders. Another problem is that the car is pinging a lot. I dont' think its my timing chain because on my dohc, the timing chain noise came from the front and those had to do with guides. On the sohc though, its seem to be pinging or clicking loud on the valvetrain. My friend told me it could be the valve clearances. So is the injector bad and can a bad injector cause a loud pinging noise if it really is running 50% duty cycle? I tried looking at the FSM to see what the resistance is for the injectors and couldn't find that as well. So do you guys know what kind of a problem this is or was the old owner right and I just need a new injector? Also, is the pinging or ticking noise going to damage my engine? Thanks a lot if you've read this long post this far and can help me.

[S13Dreamin]

Have you checked the timing? Pinging could be a result of advanced timing, and also a reason why the car will run like ass. As far as the inj. goes, have you gotten them flow tested at all to be sure?

How old is the gas in the car? Any idea what octane it is? Since you just bought the car and the last owner couldnt pass smog with it, maybe it sat around for awhile.

Could the ticking be lifters, or is it louder than that? Deeper?

Josh

[vegita319]

Umm, the gas is all new in there since i drove the car 300 miles up north from so cal to school in san luis obispo. I haven't got around to timign yet but how do i get the injectors flow tested, I want to get this car smogged the legal way that way the car will run efficiently since right now lots of smoke comes out of the exhaust and its horrible. Thanks

[S13Dreamin]

Umm, the gas is all new in there since i drove the car 300 miles up north from so cal to school in san luis obispo. I haven't got around to timign yet but how do i get the injectors flow tested, I want to get this car smogged the legal way that way the car will run efficiently since right now lots of smoke comes out of the exhaust and its horrible. Thanks


Sorry about the gas question, it may have seemed stupid, but I wasn't sure if the car was driven a short distance, long distance, or towed....just make sure, ya know?

Getting the inj. flow tested all depends on what you have available locally (or within a short distance). Some areas you can find places that can/will flow test the inj., sometimes people have to send the inj. out to places like RC Engineering, either way, you might be spending more for a flow test than you would for a set of stock inj. + o-rings. Call around, see what you can find, if nothing then weigh out your options.

I'd say there are quite a few things that could be wrong at this point if the car is spitting out smoke and running like ass, and not all signs point to the fuel system (unless you have eliminated other possibilities).

Josh

[vegita319]

No offense taken aboutt he gas question. I'm glad at the fact your trying to help, that means a lot on these forums. Well about the problem, the engine check light comes on once in a while and that's all I have to go on so far. Since the old owner tried to smog it for me but failed according to this. If you have any other ideas, it would help as well. Thanks again.

[idlafie]

Umm, the gas is all new in there since i drove the car 300 miles up north from so cal to school in san luis obispo. I haven't got around to timign yet but how do i get the injectors flow tested, I want to get this car smogged the legal way that way the car will run efficiently since right now lots of smoke comes out of the exhaust and its horrible. Thanks

***LOOOOOOOONGGG POST...read at your own risk!!! ***
Veg.....
Lots of smoke coming out of the exhaust could mean you're burning oil and that you might need a valve job. Have you tried pulling your plugs and seeing what condition they are in.
http://www.bullittarchive.com/Maintenance/Reading_Spark_Plugs/
If the spark plugs are clean, then maybe your motor has a crapload of sludge in it causing the valves to stick, ( either that or the previous owner overfilled the crankcase with oil & you are burning off the excess oil - You check the oil levels on the dipstick??). If the oil levels are okay, then try changing both your oil & oil filter. The oil flush might help remove some of the excess gunk from your valves. Before you start though, pour in a can of Gunk Motor Flush into your crankcase:
http://www.autobarn.net/chmf-3.html
You can pick this up at any auto parts store at the same time you pick up your oil & filter. Pour it into your crankcase BEFORE you change the oil & let your engine idle for about 5-10 minutes. After you let the motor flush run thru the engine for a good 10 minutes, then turn the engine off & go ahead & change your oil. Drain the old oil out & replace the old filter with a new one. Pour the new oil in to the proper levels - DON"T overfill it...you should only need about 3 1/4 to 3 1/2 quarts of oil. Make sure the car is on LEVEL ground when you refill the motor with oil.
A couple of other things you want to do to help your car pass smog is to 1). Change both the Air filter & Fuel filter. Unless the previous owner religiously maintained the car, (sure doesn't sound like it since it smoking like crazy), you're better off just changing the filters. That way you know your fuel lines won't be restricted by a clogged fuel filter & that your engine can breathe better from a cleaner filter. Replace both your distributor cap & rotor along with your spark plugs, (if you already haven't done so). That way you'll get a cleaner spark to your plugs as the car runs. Take a bottle of fuel injector cleaner & pour into your gas tank next time you fill your car up with gas. Make sure you fill the tank completely with gas before you pour the fuel injector cleaner in. After you pour the fuel injector into the gas tank, take the car for a good HARD long drive. Stomp on the gas every chance you get. You want the fuel injector cleaner to flush out the gunk in the injectors. Also, pick up a can of carburator cleaner. You'll need to disconnect & remove the rubber intake hose that connects from the intake to the throttle body. Once you have the rubber intake hose off, liberally spray the carburator cleaner into the intake manifold. Make sure you hold the butterfly valve / throttle all the way open while you do this. The carburator cleaner helps to remove any carbon buildup in the intake. Once you are done spraying the inside of the intake manifold, reconnect the rubber intake hose.
Next thing you want to do is check the rubber vacuum lines that connect from the EGR valve to the BPT valve. Make sure those vacuum lines aren't cracked, melted or clogged. If they are replace them with new vacuum hose. If they are not, then disconnect them, (remembering how they connect) and spray some carburator cleaner into the EGR valve AND the BPT valve. The carb cleaner helps to clean up any carbon buildup in the EGR Valve & the BPT valve. Once you finish spraying the EGR valve, take your fingers & wrap them around the top of the valve. With your fingertips, you want to reach around the bottom of the EGR valve & gently, (with your fingertips), push / pull up on the BOTTOM diaphram portion of the valve. By doing this, you're checking to see if the EGR valve is working properly & not binding.
Once you've done all this, then try starting the car. It probably won't start because of the carburator cleaner you sprayed into the throttlebody. Just make sure you keep your foot pressed all the way down on the gas pedal. After about 5 to 10 seconds the motor should catch & you'll see a bunch of smoke blowing out your tailpipe. Gently take your foot off the gas pedal until the motor can idle by itself. Once this happens & the motor is warm, then check your idle & timing. Your timing should be at 15 degress, (SOHC) OR 20 degrees (DOHC) & you should be idling at 700 rpm with the Throttle Position Sensor Harness disconnected.
All these preventive maintenance items should help you to pass smog.
Anyhow, hope this helps.
ID
PS: If your Check Engine Light is on, put your ECU into Diagnostic Mode & see what codes you are kicking out. Go to www.240sx.org/faq and look to the left after the page loads. Click on ECM...reading trouble codes...Post the results back here when you are done.

[vegita319]

Thanks for the long reply. I will try all of those things. I also forgot to mention that when I come to a light or the car is idling, it almost wants to die. It's an automatic so I'm guessing if this was like the dohc, it probably will stall if this car was a 5 speed. Thanks again.

[vegita319]

Well i pulled teh codes off of the ECU. I got 45 and 32. That means its fuel injector leak and EGR. It's weird, are these two things related? Like if i get a fuel injector leak, it will cause the EGR to not function properly? The reason i ask this is because i saw another guy with a sohc and got the same codes. If fixing the fuel injector leak clears both that would be great. Anyways, I checked around the fuel injector and there are no leaks! I observed as best as I could and did not see fuel coming out of the injector at all. As for the EGR, my friend unplugged the connector and found it to be corroded. He sprayed the connectors with a connection cleaner and it still threw the EGR code. This leads me to think maybe the two are related. If anyone can help me that would be great. Thanks again.

[S13Dreamin]

If you have a leaking FI that doesnt mean it is spraying into the engine bay or will even be seen outside the engine. A leaking FI can be internal as well, meaning that the injector is leaking fuel when the car is not supposed to be pumping fuel at all (when the system gets charged but no spark is applied). To test this, you can remove your fuel rail w/ inj still in and keep the lines attatched. After doing this, pressurize the system by turning the car to the on position, then look at the bottom of the injectors for fuel dripping out. If you are doing this by yourself, you might want to put a papwer towel or two down under the fuel rail just to be sure gas isn't leaking between the time you turn the key and get back to the rail.

If this doesn't identify your problem, I would do the least expensive things first, like replacing O-rings...see it that changes anything. This seems unlikely as there seems to be no external leaking from what you say. Then to the more expensive things like new injectors, possibly a new rail, etc.

Since codes 45 and 32 are "California Models" only codes, it is likely that one is tripping the other in this case. However, to find out for sure, I would try to eliminate your fuel problem first, then re-check for the EGR code, as it is more likely fuel is causing EGR problems than EGR causing fuel problems.

Good Luck.

[vegita319]

Thanks s13dreaming. I'll test that out as soon as I can and get back to you.

[idlafie]

Well i pulled teh codes off of the ECU. I got 45 and 32. That means its fuel injector leak and EGR. It's weird, are these two things related? Like if i get a fuel injector leak, it will cause the EGR to not function properly? The reason i ask this is because i saw another guy with a sohc and got the same codes. If fixing the fuel injector leak clears both that would be great. Anyways, I checked around the fuel injector and there are no leaks! I observed as best as I could and did not see fuel coming out of the injector at all. As for the EGR, my friend unplugged the connector and found it to be corroded. He sprayed the connectors with a connection cleaner and it still threw the EGR code. This leads me to think maybe the two are related. If anyone can help me that would be great. Thanks again.

Veg,
Before you go out and pull your injector rail to test your injectors, you might want to check your fuel pressure regulator along with the connector & wiring leading to the Engine Coolant Temperature Sensor. If your fuel pressure regulator is not getting vacuum to it, your engine will runner richer making your ECU think you have a fuel injector leak. Also if the connector or wiring to the Engine Coolant Temperature Sensor has shorted out, your ECU will not be getting the signal it's expecting to get from the ECTS telling the ECU that the engine has reached normal operating temperatures. As a result, your ECU will continue to dump extra fuel into the cylinders. Remember, the ECU uses the signal from the ECTS when the engine is cold to warm up the engine faster. The ECU does this for pollution control. Once the engine reaches normal operating temps, the ECU cuts back on the fuel mixture. If the ECU thinks the engine is still cold then it will dump more fuel into the cylinders. This could cause a false Injector Code reading. The best way to check for this is 1). Pull your sparks plugs & see if they are carbon fouled...
http://www.bullittarchive.com/Maintenance/Reading_Spark_Plugs/
is it just one spark plug or all four?? If it's just one, then it's an injector leak...if it's all four, then it could be a). a faulty fuel pressure regulator or b). a false signal from the ECU...meaning a bad connection at the ECTS.
2). Pull the vacuum line leading to the fuel pressure regulator. If you have a vacuum gauge connect it with a T type connector. You should be reading 34 psi on the gauge at idle.
3). While the engine is running, wiggle the wire leading to the Engine Coolant Temperature Sensor. See if you can hear a drop or increase in engine idle. Bad connector/wiring to the ECTS is common in 89-90's. I've run across it several times while working on SOHC engines. Some of these don't even kick a code either!!
As your EGR code, the excess fuel being dumped into your cylinders, may be causing your exhaust gasses to run hotter. Hotter exhaust gasses will trigger your EGR temperature sensor to active causing your ECU to kick a code. The purpose of the EGR system is to recirculate hot exhaust gasses back into your intake manifold so as to reduce the amount of pollution generated by the combustion process. You need to double check your vacuum lines running to all the equipment in the EGR system. Make sure none of them are cut, melted, partially clogged/blocked or leaking. If any are, replace them. You'll also want to test the electrical components in the EGR system such as the EGR-Cannister Control Solenoid. You will need a Nissan Factory Service Manual to do this. If you haven't already done so, I strongly suggest you go out and buy one, (DONT buy a Hayes or Chilton service manual...they dont' have the necessary info you need!!).
I hate to say this, but the only way you will be able to fix your problems is to get your hands on a FSM and follow the diagnostic / repair procedures set by Nissan. Sounds like you have a lot of work ahead of you.
Good luck!!!
ID
'95 SE

[vegita319]

Now that you mention it, the temperature gauge is a little bit higher than in my dohc. It's a tad bit above the middleso maybe that could be a problem. I'll go check it out asap. Thanks man.