Fuel injector help, pt. 2

[Superkirby]

Awhile back I asked about changing fuel injectors. I'm getting code 51 - Fuel injector circuit. I checked the injectors as best I could, and ultimately changed the one I thought was causing the problem. Either I was wrong, or it's not an injector specifically, and instead a wiring issue or something along those lines. Not sure where to go next.

I've been setting money aside to buy a bow for hunting, but at this point I think I probably might be better off to put it into the pathfinder to get this figured out, and especially to get it running better before winter rolls around.

So here's my questions - first, is there anything else it could be? I read on one sight that a guy claimed it was his MAF, even though he was getting a code for the fuel injectors. Possible?

Next, When I was looking at the injectors once I had the intake off, it's pretty obvious that the previous owner had played with this as well. There were two different types of injectors under there with two different colored paint dots. Is there anyway to find out what the engine is supposed to have, and how do you order specifically those colors? And last, depending on what I decide to spend, is it worth it to try to find the wiring harness for the injectors from a junkyard somewhere?

Sorry for all the questions. I can usually do the work without too much of an issue, but the diagnostic part isn't really my strong point.

Thanks for the help.

[AzZo]

I had a similar problem that a npora member helped me sort out.My number 5 cylinder injector was bad thats the one on the passenger side far back near the firewall so luckily I did not have to pull the intake off.I researched this and kept being told that the fuel injectors where color coded and that you had to use all the same color mine where blue dot's they come black and grey ect....Was able to aquire a good blue dot injector and the rest is history.I also had a code 51 before hand.this fixed the problem.I had also checked the fuel injectors I could reach with a multimeter and got like 12 ohm's on all but the bad one was registering a 30 ohm reading way off.Brand new fuel injectors will run $100.00 or more so a junk yard may be your best bet.Here in IOWA pathfinders were hard to find at all the junk yards and I went to all of them in my area ( QUAD CITY ) It made me think Damm these little trucks must run pretty great if you can't even find them in a junk yard.I don't know how readily available they are up north where you are but you can multi meter test them on the spot.They should run around 12 ohms more or less and other people have since told me that the color doesnt matter but mine are all the same so I cant really dispute that fact you may hear otherwise like I said I had to do a lot of research on the matter.Putting them in is the easy part.Good Luck,jack....

[Superkirby]

If anyone cares, today I got some cleaner and sprayed out the MAF sensor. While I was at it I used some electric contact cleaner and disconnected and sprayed out the connector for the MAF sensor, the back of the coil, connector behind the coild (unsure what it's for at the moment, sorry) and the four connectors above the passenger side valve cover. I reconnected everything, cleared the codes out of the ECU, and started it up. I didn't have any codes and it ran smoothly. After about a minute of idling the CEL came back on, though the idle was still smooth. Shut it off, checked codes - EGR function (new code, but also the EGR is new in late May) and the code for the fuel injection circuit. Cleared codes again, started it up and no light. A couple hours later I left for work. When first started the CEL was on, drove about a mile and it went out. All was great for about 10 miles, then the light came on again. It continued to run smooth for about 10 more miles, then began to stumble on occasion, but it didn't last long. The problem was also intermittent coming home from work. I'll check codes in the morning but it seems like it has to be something I messed with today, right? I'm thinking MAF maybe but don't know. Is there a way to specifically test the MAF to see if it's the issue? Where else should I look?

[Precise1]

Have you downloaded a copy of the Factory Service Manual from the pinned thread in the Garage section? If not, do so, it is important to have.

In the EC file on page 133, there is a simple voltage check to do but you need the picture to determine which terminal to check. It could very well be in the wiring to that connector as well, they are known to develope issues. Check for loose pins and terminal connections as well.

 

Yes, I agree that your issue sounds electrical/wiring in nature so you are going to have to keep at it, isolating and checking with a multi-meter. Electrical diagnostics aren't my strong point either, but I'm sure you can follow the basic checks in the FSM. Let us know what you find...

 

B

[Superkirby]

Thanks. I have downloaded the FSM and have been trying to study it as much as possible. I had to wait until I got paid again and then bought a decent multi meter. I work second shift so I'm going to start trying things this morning to see what I can figure out. A buddy of mine that's pretty good with Nissan/Datsun engines told me he was guessing TPS, EGR valve, MAF, or something around the IACV, though I would have to check exactly what. Could be the sensors themselves or wiring to any of them. I'll also check the wiring to the injectors.

I'll post results once I find the problem.

[deltaR50]

Check the injector clips. Those are the ones that will give u first electrical problem