Hi guys,
My friends 3.0L TF misses after going for a drive over 30 mins.
If it cools it runs fine again, but after about 30 mins again it starts missing under load, in the lower revrange.

Spark plugs and leads were changed. Worked without a hiccup for a week until it started after a 300km trim.

Plugs/leads were changed because oil from the plug o-ring leaked onto plugs. O-rings were changed and there is no longer a leak.

dont suppose you have opened up the dissy and checked for cracks, corrosion on the contacts, or even used another dissy from the wreckers to make sure the coil isnt at fault?

No to be honest I did the plug/lead/rocker cover/plug seal change for my friend and the 300km trip the car started missing again was when he was taking me to the airport so I am not there to have a look.
Just hoping to figure out what it could be. I mean, considering it only does it after longer drives I assume something must be getting heated up and causing this?
Logically it must be something related to the distributor though I assume?

most coils play up when they are hot, im assuming it could be this, a cracked dissy, or corrosion on the contacts i would assume the car would miss almost all the time. i would be more inclined to change the dissy for 1 from the wreckers, it would be cheap to find out, and if it dosent work, then not a lot of money spent

Do you know how much they cost roughly?

does it use water??? slight miss can be a head gasket when warm or hot might not be milky oil to have a blown head gasket could be between the cylinders do a compression test with a compression tester while the engine is up to temp. good readings should be over 120psi

Blown head gasket is also possible especially if its blown between cylinders or blown between a cylinder and water jacket . a second hand dissy is about 60 dollars

When I took both rocker covers off there was no sign of that beige froth from water/oil mixing.
It burns a bit of oil from what I understand though. Maybe valve stem seals, could this cause missing at all at hot temps?

well, if a head gasket is blown between cylinders, there wont be any water in the oil. but i would start with the simplest thing first, change the coil its a more then likely cause, if that dont fix it, then do a compression test, like said before around 120psi is good

Ok I will pass it onto my friend
Thanks for the help :)

How long since you changed the fuel filter? It could be startving under load. It would probably show up earlier than 30 minutes, but may be a cause.

I wouldn't have a clue but to be honest the maintenance of that car is quite neglected...
However it is under load but low rpm, higher rpm seems fine so could this be the fuel filter?

Did the missing and carrying on happen AFTER you changed the gaskets etc? If so, go back over you electrical connections and vacuum lines to be sure they're good, clean, and plugged in correctly. and check your vacuum lines aren't cracked.

When it is all warmed up, when is it "missing" the most; at idle, under load, at high revs, over bumpy/rough roads or when coming to a stop? Or is it all miss all of the time? Does this miss eventually clear or fade at any point? For example; if you take off from a standing start it misses but eventually clears with more throttle opening or higher revs? Anything you can share about the characteristics of the miss will help greatly in diagnosing the problem.

It could be all manner of things, but your best bet is to start simple; go over your work and check, look for loose/hanging wiring that may have burnt through (crank angle sensor) and check your vacuum lines. PUT YOUR WALLET DOWN. Save your cash until its genuinely needed, or for celebratory beers when you find the problem was as simple as a loose injector connection.

Skapper, it was missing lots and oil was found on the plugs from the o-rings.
o-rings + gaskets + plugs/leads changed and it worked perfect
After a 300km trip it started, but not as bad.

It misses:
Lower rpm range, with high throttle

It does not miss:
if throttle is pressed lightly
higher rpm, full throttle

hi there,

just curious if you ever sorted this out?
my wifes is doing the same thing now, if it is turned off for a few minutes it starts fine for a little while

No never figured it out.
It was not my car, rather a friends and even though he said things got better after the plug and lead change, it didn't go away completely.
He did not want to spend money on the car (had 360,000+ km on it) but I suspect somehow oil was fouling the plugs. Maybe valve stem seals (not really sure)