7MGTE misfiring, help!

[modmonster2008]

Hey guys recently my car started acting up and i checked my spark plugs and wires looked bad and all broke :3d_frown:, so i replaced it and still the car is having the same misfiring, no codes or anything that looks broken any input about this would really help right now, oh and BTW ive been hearing like a grinding bearing noise coming from my Cam position sensor, could that also be it? But I dont want to spent $300 on a new sensor to find out its not the reason, please let me know whatever i should check on, thanks!

 

[Enraged]

If its the bearing in the cps, you can rebuild the cps and replace the bearing. You can get a kit here http://twosrus.com/catalog/product_info.php?cPath=&products_id=66

 

[modmonster2008]

Could that also be the reason why the car is misfiring? I changed out the head gasket about a month ago and shes been holding up fine since then, no water or oil loss, no mixing of the two, the misfire just randomly showed up earlier today, but for the CPS ive been noticing symptoms that its going out (bearing noise, hard to start in mornings, intermittent miss on idle) But i want to get other peoples input before i do anything else.

 

[Enraged]

usually the issue with the CPS is the connector. The wires get old and brittle, and often break.

 

[modmonster2008]

CPS has already been rewired, the spark plug wires get all distribution among them, I did notice when i remove the injector #4 it doesnt really do much difference to the rough idle when the others removed, make the car run worse. I have pinpointed it to cylinder 4 but what could they be? Ignition, fuel delivery?

 

[modmonster2008]

anyone? im hoping its just an external motor issue, id honestly doubt its the head gasket again as its not showing the symptoms i had when i blew my HG.

 

[thevork]

First check the spark plug again. It may be cracked in the porcelain part of the spark plug.
Also, check your coilpack for cracks. And last but certainly not least, check the spark plug gap.

 

[modmonster2008]

I hope its as simple of a problem as that, i got my injectors inspected and cleaned today, they were good. Replaced the seals, o-rings and pintle caps but im having doubts in the back of my head its another BHG (hopefully not)

 

[modmonster2008]

Updates: Checked spark plugs and all of them were still good new looking (as i did just get them a day or two ago) no cracks on the porcelain part of the plug, gaps were all even at 0.030" around there IIRC, just waiting for my CPS to come in the mail and will be reinstalling everything, keeping fingers crossed thats the only problem and not a head gasket again.. If anyone knows some info about what else could be causing this, please do shine some light in with me on this, thank you!

 

[thevork]

I've had that grinding noise once (didn't see the video until now, sorry) on my 7M and it was from the oil pump pulley, which I tightned too much and one spoke was broken and grinding all over my timing belt.

An idle this rough can be caused by the timing belt which skipped one notch or so. Can you check if the timing is spot-on ? (remove the upper front cover to make sure)

 

[modmonster2008]

Yeah i can check timing to make sure it didnt skip a tooth, and as for the noise it was the cam position sensor bearing or something inside it, at a certain RPM it would make the horrid noise and put your finger on the cps cover and sure enough you'd feel it scraping.

 

[jonahs_supra]

since you have already ruled out spark plugs, wires, and injectors
now its either the 3-4 coil pack, cps or internal issues

easy thing for you to do
on the coil pack swap your plug wires 3 and 4 around
start engine and see if misfire has moved to cylinder 3 and cylinder 4 do not misfire

if no change then try wiggling cps wire with engine running. if idle changes or misfire clears up then you have problem in cps wiring

hope this helps

 

[ians13]

check you coils with a spark tester. somes times they might not ack up if not under load but use a good spark tester to rule out the coils i have 2 sets of stock coils go bad on me.

 

[modmonster2008]

Checked compression test today, cylinders 3-4 are leaking compression to each other, i am thinking of the Titan 1.4mm head gasket, anyone have any input on this?

 

[JStoked]

That sounds like a cylinder down to me. Hate to say that but you have way to much knock.

 

[JStoked]

Do a compression test man.

 

[jonahs_supra]

Lol. That sucks
I have a few friends running this headgasket. Hp levels ranging 300-500hp with arp's
I was going to order same gasket in a week or 2

 

[modmonster2008]

Yeah, but i just want some input on the Head gasket before i buy it. Compression test showed leak between 3-4 i dont notice any knocks in person, maybe you're hearing the grinding cps and the valve tick?

 

[DOUBL3 D]

When you rebuilt it did you machine the block and head?

Sent from my ADR6425LVW using Tapatalk 2

 

[ForcedTorque]

Yeah, but i just want some input on the Head gasket before i buy it. Compression test showed leak between 3-4 i dont notice any knocks in person, maybe you're hearing the grinding cps and the valve tick?

What were your compression numbers? My guess is if you have a leak between 2 cylinders, you need a head gasket again. Also, if you replaced it once by just putting a head gasket on it, rod knock would not be surprising. Coolant in your oil affects your bearings.