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Misfire

munkee

New member
Howdy. I've been working on my wifes 01 Grand Prix SE with the 3.1. I replaced the retarded lower intake manifold gasket over memorial day weekend and put new belt, plugs, and wires on while I was at it. It ran fine for a few weeks. Then, on her way over to Helena (120 miles), it started running rough and barely made it over the pass. The SES light flashes on the highway, and stays on steady at lower speeds. I've been over the simple stuff, except for pulling codes. Is there a paperclip method like we use on the SHO or do I need a scanner? Also, I can't seem to find a manual that covers this motor. Does Chiltons or Haynes make one, or is it time for new glasses. TIA.
 


The paperclip trick only works on OBDI cars. OBDII is a whole different beast. The codes are all 5 digits long instead of 2. Many car parts stores scan for free, though, so I'd try that first.

I don't know why Chilton's, or Hayne's wouldn't cover the 3100, but there's plenty of info out there for it, as it was used in tons of GM products. Besides, I've found those books to be worthless in most cases. That's why I always track down a factory service manual for any car I buy. Night and day difference.
 
Hm. Well, I took it to O'reillys and had the codes checked. I don't know what the code number was but the reader said cylinder 1 not firing. Duh. I didn't need a scanner for that. I need to know why not. I pulled the plug and it looked fine. It had wet fuel on it. I plugged it in and layed it on the manifold and it looked like it was getting good spark. So, now what. If it has fuel, the injector should be working right? (lol) If I didn't torque the rocker properly when I did the gasket, would that cause this kind of problem or something worse. It putt putt putts really bad at idle and smooths out some at higher acceleration, although you can still tell it's missing. Need to get this one fixed and sold. Thanks in advance for your input, Chris.
 
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