Cylinder 1 misfire help pls (1 Viewer)

[paxildog]

Need some help with cylinder one misfire on 2011 lx570. I get a check engine that seems to come on after i drive it and park it for an a little bit and start it up again, and not all the time it can go a day or two and no problem. Couple of times I could feel it misfire and runs rough , once I stop it and start again it runs fine.

I have done a couple of things already,
New fuel injector in cylinder one
New spark plug
New ignition coil
New PC valve
New valve cover gasket
New Spark plug gasket , cylinder 3 & 5 had oil in spark plug cylinder but not one

Any suggestions would be great

 

[DoverMA]

Need some help with cylinder one misfire on 2011 lx570. I get a check engine that seems to come on after i drive it and park it for an a little bit and start it up again, and not all the time it can go a day or two and no problem. Couple of times I could feel it misfire and runs rough , once I stop it and start again it runs fine.

I have done a couple of things already,
New spark plug
New ignition coil
New PC valve
New valve cover gasket
New Spark plug gasket , cylinder 3 & 5 had oil in spark plug cylinder but not one

Any suggestions would be great

As long as we are firing the parts cannon, maybe a leaky injector? Floods the #1 cylinder when turned off, clears once running.

 

[paxildog]

As long as we are firing the parts cannon, maybe a leaky injector? Floods the #1 cylinder when turned off, clears once running.

I knew I forgot something on my post, I put a new fuel injector on cylinder one. Sorry I edited first post. Thanks for helping

 

[TeCKis300]

I would recommend getting an OBD-II scanner to monitor some key items including fuel trims, misfire counts, etc. That may give you more diagnostic information to go off of.

 

[paxildog]

I’ve been using a cheap scanner to read the code and clear it every time I fix something on the Lx. I looked at the live data on it but not really sure what I’m looking at. I’ll do some studying on how to read the fuel trims.

 

[CharlieS]

How did the spark plug you removed look? Fouled? Could you post a picture? I can "read" some stuff, but I'm sure we have other people on here that can "read" what it suggests even better.

Are you equipped to do leakdown and compression tests?

I know you've replaced the coil for cylinder 1, but one diagnostic I've used is moving the suspected failed part to another cylinder to see if the misfire moves. This is pretty easy to do with things like coil on plug assemblies.

Any vacuum leaks? You could smoke test the engine. I don't see how that could lead to a misfire in a single cylinder that is persistent though.

 

[TimCFJ40]

I'd go with a Leakdown test, and also borescope CYL 1 after sitting. Recently another user posted about misfire CYL 1, and found that a small break in the head gasket was allowing a small amount of coolant in CYL1 after sitting.

 

[TimCFJ40]

I hate reading threads like this because it makes me question my own mortality but here's the one I referenced.

Blown Head Gasket?

Posting this from the waiting room of Mossy Toyota in San Diego. 2013 LC with 125k miles. Maintained at the dealership. I got a check engine light, 4-lo blinking, and trac off on the dash last night. Scanned with basic OBDII scanner - got P0301, misfire cyl 1. Brought it to the dealer (just...

forum.ih8mud.com

 

[paxildog]

I hate reading threads like this because it makes me question my own mortality but here's the one I referenced.

Blown Head Gasket?

Posting this from the waiting room of Mossy Toyota in San Diego. 2013 LC with 125k miles. Maintained at the dealership. I got a check engine light, 4-lo blinking, and trac off on the dash last night. Scanned with basic OBDII scanner - got P0301, misfire cyl 1. Brought it to the dealer (just...

forum.ih8mud.com

That thread makes me sick, I’m going to do a leak down test this week

 

[paxildog]

I did a compression test, I got 185 on cylinder 1,3,5 and 7

 

[linuxgod]

How many miles on your truck?

If you pull plug #1 now, is it clean or is there any evidence of fouling?

I'm a fan of CharlieS's method wherever possible. It's how I debug I.T. systems as well - swapping known good components into a bad system and the suspected bad components into a known good system to see if the problem stays with the bad system or follows the parts to the good system.

FWIW bad plug or bad coil pack would've been my first thought

 

[paxildog]

Yeah I swapped all coils and plug, the misfire stays on cylinder one. The plug is clean in cylinder one. I’m getting really scared it’s the head gasket

 

[TimCFJ40]

Yeah I swapped all coils and plug, the misfire stays on cylinder one. The plug is clean in cylinder one. I’m getting really scared it’s the head gasket

I’d not be sure a compression test would show a small head gasket leak. Are you losing any appreciable coolant?

 

[paxildog]

I found a leaking hose the other week and fixed it. I’ve marked the coolant to watch it

 

[TeCKis300]

I’ve been using a cheap scanner to read the code and clear it every time I fix something on the Lx. I looked at the live data on it but not really sure what I’m looking at. I’ll do some studying on how to read the fuel trims.

Take a look at long term fuel trims. For the bank 1 in particular, but compared to bank 2 as they should generally be in lockstep.

This thread may help with monitoring OBD data while driving

DIY Smartphone Scan Gauge - OBD Fusion

Having spent some time messing with an OBD-II smartphone monitor app on several long road trips, I think this topic deserves its own thread. Specifically using OBD Fusion to monitor the plethora of info available on the OBD-II data port of the vehicle. I can't take credit for this, but would...

forum.ih8mud.com

 

[TimCFJ40]

I found a leaking hose the other week and fixed it. I’ve marked the coolant to watch it

Any chance it leaked enough to get hot?