engine cyl misfire 3 4 5 6

[randheer singh]

hi, i have a 2002 range rover freelander v6 3.0l and having problems with the pulse on the injector connection.heres wat happens. when i plug in the obdII reader it tells me that i have cyl number 2 3 4 5 6 misfire.
now i have test the coil on the spark plug and have replaced the spark plugs,coil and spark plug wires and done engine intake cleaning as well.
but every time i clear the codes and start the car…it runs for a few seconds and the engine light comes on and starts missing ,thus when i check the coil ,spark plugs they seem to fire but the injector pulse on 4 and 5 are there. i ahve also done comPOST http://www.ericthecarguy.com/kunena HTTP/1.1
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[Zen]

I wonder if its one of those engines that if it detects a misfire on a particular cylinder, the computer commands the injector to stop working so it doesn’t send unburned fuel to the cat and destroys it.

[randheer singh]

Not sure about that .but how do i find for wat reason does the pulse comes n goes off at the injector.
Please help

[Its me]

Use a noid light to find if you are getting power to the injectors, it will also show if the injectors are grounded…

However, due to known head gasket problems with these, I would start with a compression test…

http://m.harborfreight.com/11-piece-noid-light-and-iac-tester-set.html?utm_referrer=direct%2Fnot%20provided

I don’t want to sound like a jerk, but those freelanders are one of the most beautiful lemons ever produced….Head problems are common (and may be related to your issue)… I see them up for sale in great body and interior condition for $500 to $800 because of their expense of repair and cost of parts…. no matter if I fixed it or not I would be planning an exit strategy with that car….

http://forums.edmunds.com/discussion/8067/land-rover/freelander/freelander-problems-are-infinite

Karl

[randheer singh]

Morming, i have done a compression test on all 6 cyl n spark plug leads and spark plug plus fuel pressure and injector tests. Now they all sound very good.they are all equal results as per the specs.and a radiator pressure test.

The only thing i see is that they is. Pulse in the being of the engine start n after a few seconds that pulse goes away in just 1 3 5 injector.now i want to find why is this happening.

Please aasist n dont give on me.

[Allan]

Hello 🙂
So youre compression are good and equal. And spark are good too all cylinders?
And you lost injetor puls to cylinder 1,3 and 5? Is power feed to those injector there when this happen?

[Charles]

The only thing common to all three injectors would be 12 VDC power from the fuse/battery. Could be a bad connection between the injector rail and the fuse. Pull the fuse and look at the contacts to verify they are clean and check the wire between the fuse and injector rail.

[Allan]

ok, so all injector have 12v and not lose that.. and only injector 1,3 and 5 lose control (ground switch) from ecm.
i would see wiring diagram, but not find 3.0l v6 in freelander.. sure its not a 2.5 l v6?

[Its me]

If you are getting constant 12+v to injector lines, then that is correct. The ECU/ECM provides the ground for the injectors to fire…

Here is something that may help your search.

Something may be turning the ground signal off…. Many times a cam or crank signal is required to turn on the fuel pump or the fuel injectors (check those and the connections and wires) an issue there could cause a problem… Also there is the possibility of a theft deterrent system causing an issue… (Is there an aftermarket theft deterrent system on it?)

Also, low system voltage can wreak havok on a system.. is the battery at least 12.6 v?

All the best…

-Karl

[randheer singh]

Sry you are right its a 2.5 v6 and as of today i have tested the cam crank and 02 sensors.they are performing good, except keep loosing the injector pulse.

[randheer singh]

Hello , am confused now n pretty worried.can someone please tell me where should i start all over the diagnose from .i could missing something here.coz i now hve starting issues and even when it starts as i put it on the drive gear car wants to shut off.now its missing very badly.
So can you please tell me n guide to from a to z and so i can fix this issues…please.help

[randheer singh]

Also tell me which sensors or wires should i check in sequence so i dont miss out anything and get this done.

[Zen]

See if you can trace the trigger wire, Injector ground wire where it’s coming from. A computer or some sort of a relay. If it’s coming from the computer , there might be a problem with the computer (Ecm) itself.

[Author]

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