vortec misfire

I've got a 97 suburban w/5.7L vortec w/120,000 miles. Recently it's developed a misfire. OBD-II scan returns only one code indictating misfire detected on #1 cylinder (P0301) No other generic or enhanced pending/hard codes identified. I've replaced the cap,rotor, wires and plugs (gapped @60). This misfire is present at all rpm ranges but obviously most noticeable at idle or when first engaging transmission. The odd thing is that randomly it will dissappear under accelleration as if someone flipped a switch and will run clean for awhile. I erase the code and all is fine during the vehicle operation in which the misfire clears up, but usually the next morning problem resumes. Any help or furher diagnosis steps is greatly appreciated.

Thanks MB

Reply to
berger
Loading thread data ...

--------------------------------- sounds like a bad connection at the fuel injector or computer, or even a bad injector or computer.

Reply to
Scott M

My Tahoe had the same problem and i replaced the fuel pressure regulator and that took the misfire right out of it

Reply to
Elmer913

Ah yes, could be a fuel pressure problem too. Kinda odd just one cyl though.....

Reply to
Scott M

Forgot to mention this is a TBI fuel system.

Reply to
berger

if it's a '97 it's a vortec which is *NOT* TBI. huge differences between the two. TBI motors were produced from '87 to '95.

-Bret

Reply to
Bret Chase

MB,

97' are MPFI, not TBI. You have a dirty/clogged/crapped out #1 injector.

Doc

Reply to
"Doc"

I stand corrected, now the question, how the hell do I get to it. It does not appear these injectors are externally accessible, as I do not see any fuel rail etc. Would chiltons or like repair manual cover replacement or is this covered under the section "see dealer for repair"? Thanks MB

Reply to
berger

Follow this link:

formatting link
Kyle

Reply to
KB

pull your fuel rail and check your injector on the # 1 piston may have deposits

Reply to
Steve Cook

Dude, lose the HTML, and lose it fast.

Doc

//////////////////////////////////////////////

Signatures By The Tired Lion

Reply to
"Doc"

Aww Doc, what can ya expect from someone not smart enough to use a computer? I've found that if you filter out anyone using webtv you lose very little. Bob

Reply to
Bob

Sad but true my friend....................they all seem to be somewhat lacking in netiquette.

Doc

Reply to
"Doc"

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.