Only Firing On 2 Cylinders (1&4)

[young-gunn]

Ok, I searched and found people are having trouble with 3 & 4 on the SR's, but I have a KA and the middle 2 cylinders (2&3) are not firing, me and my friend just checked compression and spark, and it's all good, but I still cannot find the problem, maybe injectors or something? I have no clue. Please help thnx

[benemorius]

Listen closely to the injectors. You should hear a click every time they fire.

Pull the spark plug wires and put them close to the valve cover. If the spark is good and strong it should have no trouble jumping the rubber and air gap.

[young-gunn]

now I remember, we actually checked my injectors and they all have power, so that's not it, where is the ignitor? I read that this was a problem for many people, I'll check that, and I know my spark is good, I checked that already

[benemorius]

Just because they have power doesn't mean they are operating. They could be stuck closed or they could even be stuck open. Like it or not, you have missed or fudged something. You cannot have fuel, spark, and compression in good order and still have a dead cylinder.

[young-gunn]

so what things should I check on it, Injectors (They seem okay, but maybe I'm hearing the others, they don't sound perfect, plugs and wires are all fine, I think it may be something worse, is this sort of common? What is everything I should check?

[ricebike]

hmm, not firing on cyl 2/3? leakdown test to see if head gasket area between them are blown/not????

PS: when you do leakdown test, & see bubbles from radiator/coolant resevoir, you'll know it's gone

that's assuming you did all yo other tests correctly

[young-gunn]

ok, I want to test the injectors, it's hard to tell if they're clicking because I can't tell if I am hearing that one click or another one beside it. but I was wondering if I can swap the #1 injector with the #2 injector. I thought it f the #1 cylinder dies and the other works, then I know it's injectors, but I wasn't sure if it is safe to swap them or if they are specified. So could someone tell me if I can do this, and how to do it best so I don't screw it up worse than it already is.

[young-gunn]

ok, I went ahead and risked it, and I found that when I swap the wires from injector one and injector two, the engine shakes a little more and it starts running on cylinders 2 & 4. I later swapped wires to injectors 3 & 4 and it was running on cylinders and it was running on 1 & 3. So I obviously have a problem with the wires (2 & 3) going to those 2 cylinders. so, is there any parts I should test yet? or should I just go about swapping the injector wires with another set? I have another complete set on my old engine. And how should these be swapped? I noticed all of the wires on the fuel rail are taped together, I guess just seperate them. And, where do they de-tach from the engine? will these require cutting? or is there just a plug? I will go check it out later and see what I can see.

ok, I found that the wire going to the fuel rail runs behind something and I can't see further than that. My dad has said something about it being the computer causing this? Is this possible? he could just be trying to make me spend money on the car that doesn't need to be spent (he hates that I own a Nissan and not a ford). But does anyone know what to replace? I need to know this by like tommorrow night because I am going to wrecker on friday to gget all of the parts that I need yet. thnkx
Modified by young-gunn at 6:18 PM 6/21/2006

[hudy]

It will run bad if you just swap the wires between the injectors. How do you know it is #2 & #3?

[young-gunn]

when you pull off the spark plug wire, it almost dies, when I pull it off #2 or #3, it doesn't change, I'm thinking maybe there it something plugged in wrong on the fuel rail? can someone maybe give me a diagram of this? I don't know if I can make sense of it, but I'll try. lol

Could there be somehting not fully plugged in or something cause these 2 not to get the power to fire? I just realized there is no fuel rail on my other engine, I would need to get new injector wires if they are the problem, or used ones off the ars at the junkyard this weekend. Any help or thoughts on this would really helpm, I want to be able to find the problem by tommorrow night, I'll try anything that is said that seems reasonable, thanks.

[ricebike]

easiest to check the harness side of the fuel injector w/ a noid light

i think GM style would just plug in there...

there's also procedures in the FSM that you can use w/ a voltmeter/ohmmeter to check for continuity & battery voltage...

[young-gunn]

ok, I was thinking maybe there could be a problem at the computer or something, I don't think just like cutting off the ends of the wire where it connects and putting new ones on there would do anything, the proble most be further up with the electrical, this is really annoying me, there must be someone who knows what the problem could be, and why would it only be on these 2 cylinders?

[young-gunn]

Ok, this is getting wierd.

I just went out there to check for power in the wires going to the injectors. The red wires all have power. the opposite wires (color is different for each cylinder, white, blue?, green, black) when I check those on Cyl 1 and 4, the car dies. when I check them on cyl 2 and 3, the idle picks up and it sounds like it's running smoother almost. I don't know why it doesn't die on these 2, but instead, picks up the idle. I don't have a second person to pull out the plug wire, so I don't know if it is running on that one or not. I also noticed when I checked 1 & 4 and they died, the car had a little trouble starting up right after. But on the second try to start it, it would start fine. The 2 cylinders that were not running seemed to have a weaker amount of power compared to the other 2 that were running. So I have no clue what is going on now.

[benemorius]

It sounds like you're checking with one of those automotive light things. If that's the case, you need to clip the wire on the positive battery terminal when checking the "other" wires on the injectors - not ground. You may have to cup your hands around the light and your eye to see it, but you should see a dim flicker several times per second while the engine is running. That is the signal coming from the ecu. If you have it on 1 and 4 and not 2 and 3 then you need to check for continuity on those wires between the injectors and the ecu connector.

[ricebike]

i wouldn't be checking something that sensitive w/ those things; use a voltmeter or that noid instead...

+ 1 w/ the continuity test

[young-gunn]

ok, I guess I should've thought about connecting ground to ground lol.

ok, I'll have to find my dad's voltimeter, and then check it, this problem id really bothering me, I need to find an answer, but there is so many things. Could there be any way the computer could cause this? I wouldn't think so because the 1st and 4th cylinders still fire.

[benemorius]

There really isn't that much more it could be. Yes it could be the ecu, but you're getting carried away. Most of what folks are saying aren't just random suggestions. They're walking you through the diagnostic procedure which will pretty soon wind up at the solution if you'll stick with it.

[young-gunn]

well, there's 2 firing and 2 that are not, I can't figure out what would cause these 2 injectors not to work, the injectors are good, it could be the ground on those 2 wires i guess, but where do thses wires run to? I tried to follow them, but the go beneath the ABS and I can't see where they go from there. :S

[benemorius]

...you need to check for continuity on those wires between the injectors and the ecu connector.

[lazersgm]

have you checked the ecu for any codes?

[young-gunn]

ok, I tested with a test light, all the + wires all work. but the - wores on 1 & 2 work when the injector fires (which is right), but the center 2 never turn the test light on, they are dead, What are the possible causes of this?

Some guy with an MR2 said he had the same problem and they troubleshot for a month and tried re-wiring those injectors and he never had a problem since, could this be my problem?

[benemorius]

Holy crap, dude. You need to check for continuity on those wires between the injector connectors and the ecu connector. Period.

[ricebike]

Holy crap, dude. You need to check for continuity on those wires between the injector connectors and the ecu connector. Period.

2

Quote »Audible Click Test

The easiest way to test the operation of the fuel injectors is to listen for a clicking sound coming from the injectors while the engine is running. This is accomplished using a mechanic's stethoscope, or a long screwdriver. Place the end of the stethoscope or the screwdriver (tip end, not handle) onto the body of the injector. Place the ear pieces of the stethoscope in your ears, or if using a screwdriver, place your ear on top of the handle. An audible clicking noise should be heard; this is the solenoid operating. If the injector makes this noise, the injector driver circuit and computer are operating as designed. Continue testing all the injectors this way. [/quote]did you do a compression test yet since 2 of those cylinders are next to each other?

oh, the other easier test: noid light

Quote »One or More Injectors Are Not Clicking

If one or more injectors are found to be not operating, testing the injector driver circuit and computer can be accomplished using a "noid" light. First, with the engine not running and the ignition key in the OFFposition, remove the connector from the injector you plan to test, then plug the "noid" light tool into the injector connector. Start the engine and the "noid" light should flash, signaling that the injector driver circuit is working. If the "noid" light flashes, but the injector does not click when plugged in, replace the injector and retest.

If the "noid" light does not flash, the injector driver circuit is faulty. Disconnect the negative battery cable. Unplug the "noid" light from the injector connector and also unplug the ECM. Check the harness between the appropriate pins on the harness side of the ECM connector and the injector connector. Resistance should be less than 5.0 ohms; if not, repair the circuit. If resistance is within specifications, the injector driver inside the ECM is faulty and replacement of the ECM will be necessary. [/quote]
Modified by ricebike at 1:40 AM 7/1/2006