Misfiring Issue

Need your guys expertise!

Here’s what I am experiencing.

Driving the kids to school this morning, thought I hit a bump in the road. Next thing engine felt lumpy and check light came on.
Pulled over to take a look, couldn’t see any leaking, all belts intact.
Restarted, lumpiness still there. Clicked it into Drive and felt a little worse. Eased off the brake to slowly roll forward, felt like I was going over bumps (this was more prominent at low speed)

Just managed to get myself home by being in Neutral on the down hills and taking it slow when in drive.

My first thoughts are torque converter? I haven’t lost any gears at all.

I haven’t tried to put it into 4HI or 4LO yet.

what is everyone’s thoughts?

thanks

 

My first thought is, check the code for the check engine light.

 

Seems obvious.

 

Honestly sounds more like it's misfiring, but check engine light should confirm. That will be P0300 and associated cylinder codes, such as P0301 for cylinder 1 etc.

 

That was my thought as well. Which then leads me to the TB. Oof.

 

Waiting on a friend to bring my code reader back this evening.

Just restarted on the driveway. Engine feels lumpy still. But I’ve never experienced a misfire from a V8 so unsure if that could be it. The feeling different in Drive threw me and feeling bumpy when moving.

 

Timing belt was done just before I had it.

 

With the truck running, is the exhaust gas coming out of the tail pipe consistent? Or do you feel pulsing, as if not all of the cylinders are firing in rhythm? If you're not in gear, then the transmission shouldn't be affecting the engine running.

 

From what I can tell yes. The issue is still there in Park so you’re right, it rules out transmission.

It just threw me off when it felt a little worse as soon as I put it into Drive.

 

Timing belt was replaced 40,000kms ago by a Toyota dealership.

 

Putting in drive introduces additional load to the engine. If not running properly, it will likely run worse under load.

 

I think until we know what the CEL code is, there's really no more use in speculation. Will be waiting...

 

I think you're going to find it's a bad coil, or a bad plug. Will know when you pull the code.

If it's, like, P0302, i.e. misfire on cylinder 2 (passenger cylinder nearest to radiator), swap the coil from cylinder 4 next to it, clear codes, and see if the code changes to P0304. And while you've got the coil on the misfire cylinder out, check the spark plug for signs of misfire and/or damage.

 

P0308. Misfire on cylinder 8.

 

Ok, so passenger closest to the firewall. Passenger side front to back is 2-4-6-8. Driver side front to back is 1-3-5-7.

Pull the coil pack on cylinder 8. Inspect it. Pull the plug. Inspect it. Feel free to share pics. Reinstall the plug. Swap coil 6 over to coil 8 position, and reinstall coil 8 in 6.

Clear codes. Go for a drive. See what happens.

Remember, these trucks will technically function with aftermarket coils, but aftermarket don't fire as hot. Replace with Denso brand if the code changes. www.densoautoparts.com to find the part and DO NOT order on fleaBay or scAmazon. I recommend Summit Racing or Rock Auto.

 

Thanks,

Just swapped over and waiting for the engine check light to come on.
Seems lumpier.
Coil pack 8 was numbered up none of the others were. Pulled 8 & 6 and 8’s coil pack looked newish.

 

Newish and not-Denso-ish?

 

Code swapped to 6. On my way to get a new coil pack from Toyota.

 

It is a denso.

 

Check that plug too

 

Checked all coil packs. All are Toyota/Denso.

cylinder 8 coil pack was the only one numbered by someone previously. And looked newish compared to the others.

 

New Denso coil and you'll be good to go. Replace the spark plug too while you're in there.

It'll likely be cheaper to purchase it from a website like https://www.densoproducts.com/ or RockAuto. I'd recommend buying another to keep it on the shelf. I drive long distances in my truck and keeping a spare in the truck has saved my ass.

 

OEM is Denso. Buy from Rock Auto for about $50

 

I haven’t change all of coil packs but I did change one which was one of the faulty one. My question is having another faulty coil, can it affect the change of gears ?

 

When I had a faulty coil it would usually throw a CEL and buck like a bronco under load

 

Yes, indirectly. The ECU looks at specific parameters to order a shift up or down, and those parameters are affected by a bad coil. Things like rpm and engine load as well as throttle position are all included. If the TCU also includes grade logic, which most modern Toyotas do, then driving up or down an incline will also affect shift points.