Misfire Cyl 1- Suggestions requested (1 Viewer)

[Garrissey]

I took my 2000 LC to a shop to get checked due to a misfire on cylinder 1. As a preface, this rig had the motor replaced maybe about 170k ago at the Toyota Dealership, and it currently sits with 270 on the odo. The lady who sold it to me allowed some kind packrats to live in the engine bay for three years before I purchased it.

Anyway, the initial diagnoses indicates that the misfire did not follow when spark plug and ignition coil were moved. They also found the resistance on fuel injector on cyl 1 and the test was at 14.7 OHM. I had changed the coil, fuel injector and spark plug in an attempt to fix the issue previously. Compression on cyl 1 was at 149psi. Misfire is at idle, At higher RPMs there is no misfire.

There suggestion was to complete a cylinder leak down test, as it may have valve or seat issue with cylinder. They also wanted to check the engine timing with removing top portion of the timing cover. Possibly inspect the valvetrain.

I picked up the rig and paid the inspection that they had already completed. Can anyone share some insight into what can be the issue? If there is any additional information to help let me know, but I do not think that I omitted any pertinent information.

Ciao

 

[SteveH]

The shop's diagnostic approach seems solid so far. How about a bad o-ring on the injector? You mention 14.7 ohms resistance on the injector - is that within factory spec?

 

[Garrissey]

The shop's diagnostic approach seems solid so far. How about a bad o-ring on the injector? You mention 14.7 ohms resistance on the injector - is that within factory spec?

The shop did a phenomenal job! Does the injector not come with an O-Ring already? I was confused about this and would imagine that the O-Ring was apart of the assembly of the fuel injector as purchased.

 

[SteveH]

More here on injector o-rings and careful injector install: CEL P0307 Cyl 7 misfire. Solved! Fuel Injector - https://forum.ih8mud.com/threads/cel-p0307-cyl-7-misfire-solved-fuel-injector.1328692/#post-15302930

 

[tahoejoe]

If you already swapped injectors then also check vacuum hoses for leaks and wiring connectors. Look for tiny cracks in hoses and wiring. Could be that one of those rodents chewed through a wire.

Your compression reading seems ok. If the other cylinders are in that same range my guess is that the problem is "on top" of the engine and not in the cylinder itself, hopefully.