code 12 - Land Rovers Only

jblackbu01 · 08-26-2005, 04:11 PM

Hello All:

I'm a semi-proud owner of a 95 RRC. I'll be 100% proud once I get the code 12 problem resolved. Ever since I bougth the truck, I've had a CEL with a Code 12 and the truck ran terrible. So I swapped the MAF, and the code 12 went away. To make long story short, I then got codes for the TPS, and Engine coolant temp. sensor, so I replaced those with new parts. Then Code 12 came back. So firgured maybe the cats/exhaust/o2 sensor needed to be replaced. The cats/exhaust were shot anyways, no big deal....wth all that done I still have code 12. Any ideas?

the truck has no problems starting, but still run roughs with misfires

leaky injectors? maybe I installed another bad MAF? fuel pump?

jblackbu01 · 08-27-2005, 11:58 AM

my orginial MAF was bad, but my replacement wasn't.

the MAF connector is semi-broken. Just on the outside of the connector there are three slots for the top, and two slots for the bottom. The part that has the three slots is gone. So in the end, i was putting the connector on upside down.....what a dumb ass.....

so the CEL is now gone.....but now I have a low idle issue w/ misfires, while in gear...I believe it's the fuel filter......doing that this afternoon.....

OkieRover · 08-29-2005, 08:26 AM

I hate it when I do that.
Glad you found it though.

Did the filter fix the idle rough problem?

DallasRover · 08-29-2005, 12:08 PM

Maybe the Stepper Motor/Intake Air Control on the back of your Plenum. Sits just above the Fuel Pressure Reg, has a plastic plug connected to it. Romove and clean, clean the seat that it sits in also. Controls your idle fuel mix........I did this and it helped mine.

jblackbu01 · 08-30-2005, 11:47 AM

no the fuel filter didn't help...i believe my fuel pressure is a little low sits around 31psi. i'm thinking that the fuel pump is going....

But I've got miss fires, so i'm gonna try the cap/rotor first...

here's a list of what I've replaced so far...

plugs/wires
TPS/MAF/IAC
fuel filter
engine coolant temp sensor

jblackbu01 · 09-01-2005, 11:27 AM

>no the fuel filter didn't help...i believe my fuel pressure is a little low sits around 31psi. i'm thinking >that the fuel pump is going....

>But I've got miss fires, so i'm gonna try the cap/rotor first...

>here's a list of what I've replaced so far...

>plugs/wires
>TPS/MAF/IAC
>fuel filter

well the cap/rotor kinda helped, but once it warms up it starts misfiring again....

does this sounds like a bad coil or igition amp?

OkieRover · 09-01-2005, 11:49 AM

Has your ignition amp been moved yet?
It is shipped on the side of the distributor and there is a kit to move it to the fender where it is cooler. When it fails it kills the coil. At least it killed two of my coils before I figured it out.

sven · 09-01-2005, 12:43 PM

95's should already be relocated from the factory.

jblackbu01 · 09-01-2005, 02:40 PM

i'm thinking its the alternator.......

jblackbu01 · 09-02-2005, 08:27 AM

Well, I replaced the coil, that didn't help. I even replaced the alternator, the didn't help either. Although I did mess with the MAF again, it seems to run better with it un-plugged. But I've got no CEL.

Is it possible to have a BAD MAF, and not get a CEL?

thx

08-26-2005, 04:11 PM	#1 (permalink)
jblackbu01 Member Join Date: Jul 2005 Posts: 8 Gallery: 0	code 12 Hello All: I'm a semi-proud owner of a 95 RRC. I'll be 100% proud once I get the code 12 problem resolved. Ever since I bougth the truck, I've had a CEL with a Code 12 and the truck ran terrible. So I swapped the MAF, and the code 12 went away. To make long story short, I then got codes for the TPS, and Engine coolant temp. sensor, so I replaced those with new parts. Then Code 12 came back. So firgured maybe the cats/exhaust/o2 sensor needed to be replaced. The cats/exhaust were shot anyways, no big deal....wth all that done I still have code 12. Any ideas? the truck has no problems starting, but still run roughs with misfires leaky injectors? maybe I installed another bad MAF? fuel pump?

08-29-2005, 12:08 PM	#4 (permalink)
DallasRover Senior Member Join Date: Aug 2005 Location: Dallas, Texas Posts: 732 Gallery: 0	Maybe the Stepper Motor/Intake Air Control on the back of your Plenum. Sits just above the Fuel Pressure Reg, has a plastic plug connected to it. Romove and clean, clean the seat that it sits in also. Controls your idle fuel mix........I did this and it helped mine. __________________ Beer is proof that God loves us and wants us to be happy. ~Benjamin Franklin 1989 RR Classic 1969 Series IIA 3 Kids in College...........

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08-27-2005, 11:58 AM	#2 (permalink)
jblackbu01 Member Join Date: Jul 2005 Posts: 8 Gallery: 0	my orginial MAF was bad, but my replacement wasn't. the MAF connector is semi-broken. Just on the outside of the connector there are three slots for the top, and two slots for the bottom. The part that has the three slots is gone. So in the end, i was putting the connector on upside down.....what a dumb ass..... so the CEL is now gone.....but now I have a low idle issue w/ misfires, while in gear...I believe it's the fuel filter......doing that this afternoon.....

08-30-2005, 11:47 AM	#5 (permalink)
jblackbu01 Member Join Date: Jul 2005 Posts: 8 Gallery: 0	no the fuel filter didn't help...i believe my fuel pressure is a little low sits around 31psi. i'm thinking that the fuel pump is going.... But I've got miss fires, so i'm gonna try the cap/rotor first... here's a list of what I've replaced so far... plugs/wires TPS/MAF/IAC fuel filter engine coolant temp sensor

09-01-2005, 11:27 AM	#6 (permalink)
jblackbu01 Member Join Date: Jul 2005 Posts: 8 Gallery: 0	>no the fuel filter didn't help...i believe my fuel pressure is a little low sits around 31psi. i'm thinking >that the fuel pump is going.... >But I've got miss fires, so i'm gonna try the cap/rotor first... >here's a list of what I've replaced so far... >plugs/wires >TPS/MAF/IAC >fuel filter well the cap/rotor kinda helped, but once it warms up it starts misfiring again.... does this sounds like a bad coil or igition amp?

09-01-2005, 12:43 PM	#8 (permalink)
sven Senior Member Join Date: May 2005 Location: Centre of PA Posts: 371 Gallery: 0	95's should already be relocated from the factory.

09-01-2005, 02:40 PM	#9 (permalink)
jblackbu01 Member Join Date: Jul 2005 Posts: 8 Gallery: 0	i'm thinking its the alternator.......

09-02-2005, 08:27 AM	#10 (permalink)
jblackbu01 Member Join Date: Jul 2005 Posts: 8 Gallery: 0	Well, I replaced the coil, that didn't help. I even replaced the alternator, the didn't help either. Although I did mess with the MAF again, it seems to run better with it un-plugged. But I've got no CEL. Is it possible to have a BAD MAF, and not get a CEL? thx

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