My X has it's first running fault. Yesterday could feel a slight misfire, then EML light on, managed to get home ok and today read the codes.

P0301 - Misfire Detected in no1 Cylinder
P1313 - P1313 Misfire Rate Catalyst Damage Fault

I have checked the PCV pipe and it seems ok, I then cleared the codes. When I restarted, the EML is on again but no new codes stored and also the red transmission light come on and car is jolting when I put it into drive and doesn't seem like it would accelerate.

Would a misfire cause the transmission light to come on?

Thanks for any help.

 

As #1 cylinder is easily accesible, the first thing to do is check the coil connection to #1 cylinder.. If it looks good and electrical wiring looks good, remove the coil connector then remove the spark plug and inspect that.

 

Thanks, but isn't no1 cylinder underneath the inlet manifold? But that will be my plan when I get chance to do it later in the week.

 

Any misfire can cause enough hassle to upset the trans. Fix misfire and trans probably happy again.

Note that P1313. Don't keep letting misfires happen!

If #1 is awkward to get at I'd get a good coil and swap it in. Unless your plugs are due changing I'd be surprised if it's a plug fault.

If they are due, do 'em while it's apart.

 

Thanks JagV8. I changed the plugs at 72k and it's now done 100k. I might swap the plugs and no1 coil around from front to back to see if the misfire code changes.

 

Yes, my mistake... Sorry, lol
Rear bank far leftside plug
1 3 5
2 4 6

 

Update - Read the live data from the scanner and initially had high fuel trim readings which went to zero (ish) at 2000rpm so thought air leak. The PCV pipe rubber seemed a little soft but no splits so replaced it anyway. Re started car and was as smooth as a nut but it has a slight hesitation every now and again and gearbox light keeps coming on (no engine light this time) so i can't drive it. Fuel trims are fine:

SHRTFT1 0
LONGFT1 -0.8
SHRTFT2 -0.8
LONGFT2 -3.9

MAP Pressure is 9.2inHG and fuel pressure 54.8psi, so i seem to have sorted the air leak but why is the gearbox light coming on and why the occasional hesitaion? Any help appreciated.

 

topanga: Just spitballing...... Check the electrical connector at the bottom, front of the throttle body. It's prone to become brittle with heat & age, sometimes causing an intermittent connection. It's not a problem until you disturb it, e.g. while looking for a vacuum leak.

Sometimes you can stabilize it with a nylon zip tie or epoxy, sometimes you need to replace the connector. It's a standard Ford to Denso connector, Motorcraft WPT-1269, shown here: https://www.jaguarforums.com/forum/x...5/#post1340696

 

Thanks dwclapp, I'll take a look at that before it goes dark.

When I switched it off earlier the gearbox light was on. Just been out to it again, no light, running really well and been for a short drive, so far so good. Will take it for a longer drive later and report back.

 

With luck it may just be relearning that the fuelling is as it should have been but wasn't.

 

To build on JagV8's suggestion, you can make the ECM re-learn faster by disconnecting the positive battery cable from the battery post and holding it against the negative battery post or any ground point for a few moments. Then reconnect the positive cable to the positive battery post and drive as you normally would while the ECM relearns how to re-optimize engine parameters like fuel trim, timing & throttle position.

 

I did disconnect the battery for a couple of hours but didn't touch the leads together. It does seem to have made a difference though. When I restarted it, I left it to idle until the temp gauge got to half way, then went for a gentle drive. Been out today also, 85 miles later, no lights and I swear the engine idles smoother than before and at slightly lower revs. Thanks for all the advice chaps.

 

Sounding good!