Hi,
Finally got my XJ6 3.0L running after putting on 2 used heads. and tracing an ECU earth issue. But:


I get misfires on Bank 1 P3000 P0301,0303,0305 and P0442.
I have checked LT Fuel trims while driving using Torque Pro
Restricted performance comes on at light load and decel.


At Idle Bank 1= 6.2 Bank 2 =1.2
At 1500 Bank 1=-8 Bank 2=10
At 2000 Bank 1=-10 Bank 2=19


Fuel pressure is 55-58 psi
Replaced all upper/lower manifold gaskets.


Any ideas where to start it? has also had new NGK plugs
or what else should I monitor with Torque?

 

Check out the coils and plugs as well as for vac/exhaust leaks

It would be a good idea to also read the "fuel trim primer" so you have a good understanding of how this works

Cheers
34by151

 

Hi having replaced the manifold seals was hoping vac leaks were minimised. new standard plugs.
Have looked at fuel trim primer, and other fuel trim vids and not sure what my trims are telling me?

Thanks for suggestions

 

The P0442 may be causing it all. Leak=can't control trims.

 

Thanks JagV8,
Just checked It is P0441 still Evap.
with p1313 and P1316 as well as misfires on cyl 1,3,5
Lots of threads with cure by changing gas cap some with purge valve swap: but would that be enough to give misfires?

 

Start with all the items you removed/replaced
It's unlikely that a fault developed in a new area (one that you did not touch) while your repair was going on.

To track down the leak the most effective ways are a vac pump or a smoke machine.
I posted details on how to make one for under 10 bucks.
see here https://www.jaguarforums.com/forum/x...-leaks-117917/

You also need to take care of the misfires, try swapping plugs and coils to identify the faulty parts.

Cheers
34by151

 

Or just keep watching STFTs and spray tiny amounts of burnable gas near each suspect until trims go wild. Costs next to zero.

 

Thanks again guys
plugs and coils have been swapped out before.
Gut instinct is its vac/air or evap or even slight exhaust leak even though it had new manifold gaskets.

JagV8will do, but its blowing 40-50 mph at moment, gas could be way to go later in week when it calms down.

 

It was bad here, too. (You need a garage.)

 

Could a propane torch be used for this?

 

haha
got a garage but it was built in 60's, could barely fit an old mini into it!!
And the xj doesnt have a sunroof!

 

Yes, propane is OK (don't light it) but just tiny amounts - you're not trying to set fire to the car!

For a feel of what the STFTs do, spray a bit of propane into the air intake - that's a sort of big air leak

(That's not a good test, but hey. You could always remove a vacuum hose slightly and spray there.)