LY7 misfire

[granitestatedestroyer]

2008 Cadillac CTS

180k miles.

Single cylinder misfire.

Not the plug or coil.

What are the chances it's an injector, and not the timing starting to fuck itself?

 

[TrikeKid]

Single cylinder misfire is unlikely to be anything timing related. Injector or valvetrain are more likely

 

[Johnny Longrifle]

Compression test. Broken valve springs are common in newer GM garbage. Do you have a fuel psi gauge? Pressureize the fuel system and you can energize the injector with a couple test leads and watch for pressure drop. Super scientific way to test if the injector is working.

 

[Rttoys]

check the injector connector. Start it and move the connector to see if it fires and stops.

Could also be a broke valve spring, like earlier stated.

 

[Jackie Treehorn]

I’ve had bad knock sensors show up as single cylinder misfires before.

 

[DMG]

Single cylinder misfire is unlikely to be anything timing related. Injector or valvetrain are more likely

I have seen a bunch of 3.6s start misfiring on one cylinder when they jump time.

 

[granitestatedestroyer]

I have seen a bunch of 3.6s start misfiring on one cylinder when they jump time.

In the ones you have seen do this. Do the valves survive, or do they make contact and bend?

 

[DMG]

In the ones you have seen do this. Do the valves survive, or do they make contact and bend?

I have never seen one with bent valves and I was a caddy tech for years. They run so bad one or 2 links out of time that people stop driving them.
I have an 07 CTS that I bought with stretched chains to fix and drove too much so now it is misfiring on the whole right bank. It started with one cylinder misfiring.

 

[granitestatedestroyer]

I have never seen one with bent valves and I was a caddy tech for years. They run so bad one or 2 links out of time that people stop driving them.
I have an 07 CTS that I bought with stretched chains to fix and drove too much so now it is misfiring on the whole right bank. It started with one cylinder misfiring.

Thanks.

I dont have my hands on the car yet. Probably tomorrow morning

Buying it to flip. Miles are kind of high, but I'll be into it cheap enough that I should still make a couple thousand.