Introduction + Need help on a 4.6is Misfire problem.

[ChumChuck]

First of all I'm Charles!

Originally from Québec but I recently moved to Whistler, B.C. This is my second 4.6is .. Yeah I know.. My wallet hate me! I just love this truck and for the price no SUV can beat that! Anyyyway!

So let begin with my first 4.6is. Had it for 4 months until my dad totaled it. It had M3 wheels for winter and other then that it was stock.








Now the new beast!

Only mod so far are yellow highbeam and fogs, X pipe, semi gloss OEM Style 87's and Inno Roof box.





Now the really important part, my misfire problem! When I cruise 100km/h and I go uphill in 5 the truck give me some misfire.. Downshift in 4.. No problem. So far I changed tranny oil + Filter (OEM),cleaned my MAF, Spark plugs .. I have no check engin code.. Please don't tell me it's a torque converter problem.

Thanks Guys,

Charles

[Ricky Bobby]

I can't believe your dad totaled an Estoril :tears:

[ChumChuck]

I know.. Don't remind me haha!

He drive a 2014 Land Rover Evoque .. I drove is Evoque and let me tell you it's the most impressive machine I drove in snow! I kind of understand why he lost control and crashed my X5 coming from the Evoque.. But still poor Estoril!

[Pierce330]

I can't believe you let your dad drive your estoril hehehehe

[ChumChuck]

After one year he still feel bad..

Any Help for my problem?

[Pierce330]

I may have missed it in the above, however, did you get it scanned? May have been a hiccup...I would start by changing the plugs/coils...however, plugs first, since the coils are expensive...then go from there...

[ChumChuck]

Plugs was change and no codes .. I checked that to.

From what i read it's torque converter .. :/

[TQ2K]

Check if the fuel pump or filter has been replaced.

Not sure if a fuel pump issue but mine just failed and looking back had noticed some subtle signs like an out of the blue misfire like behavior w/o any codes.

Check Test-6 in the OBD Cluster and see if fuel is transferred from left to right(have more) tank.

Observe if the misfire hiccup happens with less than half fuel is available while driving on an uphill(more load on the fuel pump) and/or turning to the right.

[ants_oz]

Originally Posted by ChumChuck

Plugs was change and no codes .. I checked that to.

From what i read it's torque converter .. :/

Torque converter won't cause a misfire mate.

Misfire will be one of two things - fuel or spark. On multipoint EFI vehicles, I always tend to look at the spark side of things first.

If you want the bush mechanic's way of diagnosing something like this, disconnect one plug lead and go for a drive. It'll run like shit. But see if you can reproduce the misfire. If you can, then reconnect the plug lead you disconnected, and disconnect a different one and repeat. When you can't get the misfire, that's your cylinder in all likelihood. Work backwards from there. Can you swap coil packs between cylinders? If so, do it and see if the misfire follows the coil pack. If it doesn't, try something else. Like a spark plug.

There's plenty you can do without actually replacing any components, to isolate exactly where the problem is coming from.

[ChumChuck]

Thanks for the help guys.

I know the TC won't cause a misfire but the way my truck act it was the easy explanation .. It only do it around 100km/h going uphill in 5.. If I downshift it's all good.. Or sometime when it's cold outside and I just started it, it feel like my wheel are full of snow.. So those are the main reason I forgot to said that lead me to the TC .. Since the plug are new I'll check the coils.