Joined: Feb 2017

Posts: 2

Likes: 0

Hello. I happen to live in Sweden (you must excuse my english) and unfortunately there aint a lot of mecanics who knows about these cars. Anyway, I bought my Suburban 1500 with the 5.3 Flexfuel a year ago and he who sold it to me wasn't the most honest man... Problem started almost imidately, the check Engine light lit up when the car is idling for too long. And Stabilitrak and traction control also lit up when youre standing still, and when that light is on, it's quite a rough change from 1st to 2nd gear, but the light always go off after a while you've come in motion. Took it to a shop who read the trouble code, P0300-00 misfire detected cylinder 2 and P0327-00 Knock sensor bank-1 circuit low voltage . I changed sparkplugs and wires. I tried moving an ignition coil(hope that's the right name) from a "healthy" cylinder to 2nd, but nothing changed, still misfire on 2nd.
One theory is that previous owners used mostly the E85 fuel, and because our E85 is much drier than yours(15%gasoline and 85%ethanol) that might have caused damage to the cylinder head and valves. Did a compresion test but even if the 2nd cylinder had the lowest pressure, the difference wasn't that big.
Would be grateful for any ideas on this matter, Thank you

Joined: Feb 2008

Posts: 2,900

Likes: 4

Joined: Feb 2017

Posts: 2

Likes: 0

Thanks. I read the article and of course it might be with the tps. But if I understod it right, those cars had an "uneven" idle. I think my Engine idles quite even, but it's on those low rpms the misfire appears. Sadly it feels like an intermittent problem. Yesterday I started the Engine and while it was idling I sprayed a lot of starting gas around the intake manifold to see if something was leaking in air, but nothing happened. It took me a couple of minutes and usually the Engine light would have lit up, but it didn't. Sometimes I miss my old -73 Corvette with carburetor and "easy to understand" technique......