Running Stupidly Rich

Just in the process of installing EFI....

...Its running like a bag of nails idle hunts and is slow to pick up...

...Just removed plugs and they are really really soothed up.

Any ideas what would cause this?

Check spark and it looks ok..

Mine runs as i would expect and it does have very sooty plugs, so maybe this is pointing you in the wrong direction.

Otherwise, check the AFM flow rate base reading and check the CO trim setting. Check the flow rate when you rev the engine up, see if it reads as expected (smooth voltage increase)

Not sure what would make it hunt on idle, must be having a hard time keeping itself running. Checked igntion timing recently?

Have you installed the engine speed sense correctly to the coil with the required resistor?

have you established if it is misfiring or just lumpy?

are you aware of Rover 14CUX Hot Wire Mass Flow EFI: Service and Troubleshooting

VERY helpful for EFi diagnosis...

Possible air leak would make it run rich and lumpy. Also check coolant temp sensor is giving the right resistance and hasn't mistakenly had its plug swapped with the fuel temp sensor.

As noisy said ignition timing would be a good first check if it's slow to pick up revs

dirtydiscov8 said:

Possible air leak would make it run rich and lumpy. Also check coolant temp sensor is giving the right resistance and hasn't mistakenly had its plug swapped with the fuel temp sensor.

As noisy said ignition timing would be a good first check if it's slow to pick up revs

Click to expand...

I got it !

Turns out I had blocked off the vaccuum to the breather on the head on the plenum, as I didn't want the contaminated air going into the recently cleaned plenum...

...So as more air was been pushed through the MAS for a given throttle opening it was running MEGA rich.

Moral of the story, is you need the bleed from the head cover breather, or at least an air bleed going into the plenum to make the mixture correct.

Man, it has been emotional!

The little plastic T piece that splits the pipe from the breather to the plenum and the throttle body actually has a little brass destructor fitted into the plenum piece so that the diameter is around 1mm, to restrict airflow.

Mine was actually blocked up with ****. Once cleared it took a few goes before it fired up, presumably it had to adjust!

close to giving up with the rv8 yet porny or are you in too deep now?

pornstarmax said:

I got it !

Turns out I had blocked off the vaccuum to the breather on the head on the plenum, as I didn't want the contaminated air going into the recently cleaned plenum...

...So as more air was been pushed through the MAS for a given throttle opening it was running MEGA rich.

Moral of the story, is you need the bleed from the head cover breather, or at least an air bleed going into the plenum to make the mixture correct.

Man, it has been emotional!

Click to expand...

Where exactly is that breather? I just failed MOT for spitting out 7% CO2! I'm thinking there is a vacuum issue. Cheers.

I assume you mean 7% CO?

Anyway, the vacuum port is passenger side front corner of the plenum, should be a T piece nearby that joins it to the big pipe which runs to the breather/filter thing on the rocker cover.

If you have that much CO, it is indeed rich. How was the HC reading?

CO means rich, HC means misfire (basically)

Also check the CO trim setting on the airflow meter

Fango said:

Where exactly is that breather? I just failed MOT for spitting out 7% CO2! I'm thinking there is a vacuum issue. Cheers.

Click to expand...

It is controlled by the Afm you need to turn that down to set the base co

Have you played since I set it all up lol

vougese39 said:

It is controlled by the Afm you need to turn that down to set the base co

Have you played since I set it all up lol

Click to expand...

I just put in the correct land rover coolant temp sensor and OE FPR, new plugs...running smooth, but still won't know about the richness until I retry MOT. I could pull the plugs in a few miles to see how they look I suppose.

Just did a full chassis swap the right way and replace most things, good fuel pipe, new loom, etc. Just trying to find a reasonable paint job..have new doors and smooth roof to put on, then hopefully I'll be done before i send her to the states. I never did get that schematic from you though suppose that is long gone by now.

Just a thought - are you running the correct tune resistor ? If you run without oxy sensors on a closed loop type resistor it will run very rich.

Mr Noisy said:

The little plastic T piece that splits the pipe from the breather to the plenum and the throttle body actually has a little brass destructor fitted into the plenum piece so that the diameter is around 1mm, to restrict airflow.

Mine was actually blocked up with ****. Once cleared it took a few goes before it fired up, presumably it had to adjust!

Click to expand...

Hi, sorry to revive an old thread but is this part an EER4765 as I found mine broken and now is even more broken in little bits!

ERR4765 - ALLMAKES OE T Piece/Restrictor - Plenum Hoses E - Land Rover Parts Direct

Thanks all

^^^^

Certainly looks like the right one to me mate