[seankbrown]

Hello everyone. I am new to the forum so please forgive me if this issue has already been discussed. I have a 2000 Escalade with about 140k Miles. Always been a great running vehicle since I bought it about 6 months ago. Recently I started noticing a misfire under load while climbing a hill with speeds between 60 and 70mph. After the misfiring and vibrations which are very noticeable the ses light illuminates and when checked with a scanner reads the p0307 code for misfire on cylinder 7. After it happened originally I replaced plugs, wires, cap, and rotor, I could definitely tell an improvement in performance after the tune up but the misfire was still there. Next thing I tried was running some seafoam in my gas to clean up any bad fuel that may have contaminated the system. Still no luck misfire still there. Last night I replaced the crankshaft sensor, thought that did the trick and then today(on the same hill as always) the misfire happens again. I am so tired of trying to figure out what's going on. I'm at a loss. Any help would be greatly appreciated. Thanks in advance.

 

[the cadillac man]

Could be a injector as it's likely a fuel delivery issue

 

[seankbrown]

@the Cadillac man. Are the injectors on the 5.7 easy to replace? Can this misfire cause engine damage? If it was fuel delivery wouldn't it not be isolated to a single cylinder?

 

[the cadillac man]

Should be
Not sure how it's set up on your year truck

I can check my service manual and see which cylinder it is that you need to replace the injector on if you want

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A misfire will not cause engine damage

 

[seankbrown]

@the Cadillac man... that would be great thanks. I know its cylinder 7 as I keep getting a p0307 code. cant find any info on replacement though. Thanks in advance

 

[wesyder]

@the Cadillac man... that would be great thanks. I know its cylinder 7 as I keep getting a p0307 code. cant find any info on replacement though. Thanks in advance

the 5.7 has that spider type injection if there is a bad injector i think the whole deal has to be changed

 

[seankbrown]

@wesyder.. From the research I have done I believe you are correct. Doesn't look like the type of job I want to tackle myself either. Guess its off to the shop I go to get a proper diagnosis. I was hoping it was something else other than a stuck injector. Guess my crappy luck prevails.

 

[the cadillac man]

the 5.7 has that spider type injection if there is a bad injector i think the whole deal has to be changed

Oh yea I forgot that the 5.7 had the spider type injection system

 

[AirForceOne]

IF you are mechanically inclined, the injector swap isn't terribly bad on the L31.
https://www.youtube.com/watch?v=LrPrPUgNLf0