Locating fuel injectors problem...

[wannabevip_g50]

Car - 94 Q45

After hours of searching the forums, and q45.org, for a topic specifically addressing the process on locating the fuel injectors, I've only come up with threads addressing how to easily remove them. I've done fuel injectors on a Lexus (I know, I know) but that was years ago and I apparently have a brain fart now and can't think of where I'd find them when going to replace my spark plugs since I want to get everything done together.

Please don't crucify me for this. Thanks guys! :-)

[OwnerCS]

The injectors are located under the intake plenum. In the picture below, the plenum is off and the injector rails are in plain view. The purple spots are the injector heads where the electrical lines plug in.

Have you tested the injectors to determine that you really need to do a replacement?

[wannabevip_g50]

Yes, engine is throwing a code that says connection to one fuel injector is bad (high OHM reading) which is causing a misfire and the knock sensor to go off. Rough idle at stop light, little to no acceleration. Going to do all 8 spark plugs so might as well do all 8 fuel injectors. This Q45 has gone through some neglect.

On a side note, transmission fluid is pretty dark too. Going to change filter, drain, and refill and hope to make the transmission last a little longer. Shifting is not bad, but on cold startup it takes a few seconds to go from R to D (result is high RPM's when shifting). So much maintenance about to be done.

[OwnerCS]

When you pull spark plugs, if you find any oil on the plugs (mostly in the thread area) the valve covers are leaking oil into the spark plug chamber. You might find you need to also resolve that type of oil leak.

Also, there are threads about injector testing to determine the exact injector that is failing. Do you know the failing injector number?

[wannabevip_g50]

I do not. I did read those threads, however it still seems a bit hazy to me.

[maxnix]

The reread them. Injectors need to be ohm tested cold then warm. Calibrate your DVM.

[goody90q45]

You can ohm test the injectors and KS at the harness connectors. Personally, I'd be hoping for #1, #2 or #8 fuel injector to be bad so the plenum wouldn't have to be pulled to replace it.

http://q45.org/ohminjectors.html

[wannabevip_g50]

Thanks for that info. I hope the plenum doesn't have to be removed either. Did this on a Lexus LS, not looking forward to doing this on an Infiniti.

[wannabevip_g50]

Also, I hear a lot of mixed reviews on BG44K. I hear people say they "lost horsepower" or that their "engine was never the same (bad)" after using it. But I see people talk religiously about it here on NICO. Can anyone give me some more insight to it? Should I pour a can of BG44K into the gas tank immediately before or after the new fuel injector(s)/spark plug(s) install?

Any other advice for a n00b like me would be greatly appreciated. :-)

[Q451990]

BG changed the formula on 44K several years ago. The consensus seems to be that the old formula was good, and the new one is not bad - but not as effective.

The plenum has to come off to replace the injectors. There is not real overlap between that job and the spark plugs, except for removing the intake hose. While the plenum is off you will want to replace all of the hoses, knock sensors (if showing any cracking in the case, and they probably will) etc.

It's not a job you will want to repeat... especially if it's a car you're going to keep for a while.

Heath

[goody90q45]

Should I pour a can of BG44K into the gas tank immediately before or after the new fuel injector(s)/spark plug(s) install?....

The BG44K is tough to get except through mail order or getting a flush done in a shop. I and others have had good success using a bottle of Redline S1 fuel system cleaner in a 1/2 tank of gas. If you haven't got any injectors too far out of range in their ohm readings the Redline will give some improvement. I'm in CA and have found it at Pep Boys and Napa Auto Parts for about $8-$9 a bottle.

Ohm testing the injectors and KS tell you a lot about how/why your engine is struggling. What's your numbers? If they're all good we can move on to other PM/fixes.

[wannabevip_g50]

BG changed the formula on 44K several years ago. The consensus seems to be that the old formula was good, and the new one is not bad - but not as effective.

The plenum has to come off to replace the injectors. There is not real overlap between that job and the spark plugs, except for removing the intake hose. While the plenum is off you will want to replace all of the hoses, knock sensors (if showing any cracking in the case, and they probably will) etc.

It's not a job you will want to repeat... especially if it's a car you're going to keep for a while.

Heath

So it's not true what the guy said above about fuel injectors #1, #2, and #8 being able to be changed out without having to remove the plenum?

[Q451990]

Yes, those can be done... especially 1 & 2. Are you lucky enough to only failures in those locations?

Heath

[wannabevip_g50]

A few more questions:

1) I wanted to ask, should I use BG44K to try and get some of the gunk out of the combustion chambers BEFORE or AFTER new fuel injectors install?

2) I'm using something VERY similar to this (from AutoZone and it's orange in color) to try and OHM the fuel injectors myself:



But whenever I hook it up properly (per the diagram above in this thread), all I get on the digital display is "OL." I know the dial on the meter is selected to the "Omega" sign which the box said is to read OHMS. So WTF?

3) Don't get on me about purchasing remanufactured injectors, but please tell me what the difference is between these two: http://bit.ly/i1n3vr and how I would determine which I need (please click link to go to thepartsbin.com, one of my fav stores, for a comparison on the injectors in question). I noticed that many people talk about white, black, or no color injectors. WTF again?

[OwnerCS]

Here is a thread about having two injectors fail at the same time. I followed goody90q45's instructions for testing to locate the bad injectors. So 3 and 7 were bad news from an access standpoint.

Some people replace all injectors on a bank (odd vs. even) when one fails as they all should have a similar spray pattern for the O2 sensors. I replaced all eight of mine with some BWD "black label" that purportedly have the most closely matched spray patterns from that vendor. I know you can find rebuilt/serviced injectors from sponsors like DeatschWerks for a lot less than the cost of new BWD black label. I'm sure other members have sources for rebuilt or aftermarket injectors that work fine.

v8-became-a-v6-cyls-3-and-7-appear-dead-t503163.html

[wannabevip_g50]

And I've been doing everything right (as far as red pin to positive on battery, and black pin on each pin of fuel injector connector to test each injector) but my digital reader won't get out of the "OL" display. My digital reader is almost exactly the same as the blue one above (purchased from AutoZone) but it's orange. The booklet says to test OHM's, the meter needs to be switched to the "omega" sign but that's what displays a permanent "OL" on the digital display.

Also, from those two injectors I showed, which should I purchase?

[goody90q45]

Pull the center ornamental cover and then the connectors on fuel injectors 1 and 2 and take readings directly off the FI pins. You can do the same with #8. Some meters have a x1000 setting (or is it x.001?). You're on the correct setting, the omega symbol is ohms resistance, so checking the owners manual would be my suggested next step. Was the key off during the check? Try with the key in the ON position.

I've got a 10 ohm resistor from Radio Shack ($2) taped to the top of my multimeter as a quasi-calibration check to make sure it's reading in range.

[Q451990]

Definitely turn the key on during the check. The later models had the injectors on a switched circuit, so it isolates the injectors with the key off.

Heath

[wannabevip_g50]

Heath, which of those two injectors should I purchase?

[Q451990]

If you go with aftermarket injectors, I would do it with all of them, or at a minimum on the same bank... Otherwise the injector latency will differ too much between injectors and you will end up with some rich and some lean cylinders. The ECU can only adjust the injector pulse width (open time) for an entire bank - not on individual cylinders.

Remember that OwnerCS has a different design injector than yours... It all depends on how much you're looking to spend and how long you want to wait before going under the plenum again. I replaced all eight with the BWD phase II (94-96 style), rails, subharness, every hose, and knock sensors and their harness all at the same time. My hope is to not go under there again for at least another 8 years.

g50-aftermarket-injector-alternative-t347484.html

Heath

[wannabevip_g50]

Heath, I understand all that and I plan on changing out all 8 injectors, replacing any cracked hoses, and installing new knock sensors (there's two, right?)...

But my question was between these two fuel injectors (click link): http://bit.ly/i1n3vr

Which of them should I buy? There is a price difference and an aesthetic difference. When I contacted thepartsbin.com, they asked me whether my injectors were "black" or "white." If they were "black," to go with the more expensive of the two. Can you clarify on this? Please view link!