Bumpy rpms
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Senior Member
Joined: Jun 2002
Posts: 595
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From: Schaumburg, Illinois
Engine: slowtacular L03 305
Transmission: slushem 700r4
Bumpy rpms
OK i have gone through a good chunk of the ignition and such so far. I have replaced the cap, rotor and 7 plugs (couldn't get to the #5 plug in time to clean up and get to work). I know the car needs plug wires and probably a fuel filter. Anyway i noticed today that when i held the revs anywere from idle to 4k or so (estmation since my tach seems to think my engine revs to over 7000rpm) it will both bounce on the tach and you can feel and hear a bit of a bounce. Would this be timeing, that one plug, plug wires, fuel what? Thanks. Oh, it is a tbi rs camaro.
There are a lot of possibilities, but I wouldn't even begien diagnosis until ALL the plugs are replaced with fresh, correctly gapped plugs.
Once that is done,you need to forget about the tach in the dash and use a handheld instrument for diagnosis. Once you have your hands on it, you should also test the resistance of each plug wire (too bad that you didn't do that while changing the first seven plugs). Don't forget the coil wire (if you have one).
A little more information would also be helpful, such as idle RPM and quality (is it "missimg" at low RPM and idle, too?), vacuum reading at idle, condition of any of the plugs you removed (they can be your best barometer for engine condition), and any other abnormal symptoms you might experience.
But begin by completing your plug change first.
Once that is done,you need to forget about the tach in the dash and use a handheld instrument for diagnosis. Once you have your hands on it, you should also test the resistance of each plug wire (too bad that you didn't do that while changing the first seven plugs). Don't forget the coil wire (if you have one).
A little more information would also be helpful, such as idle RPM and quality (is it "missimg" at low RPM and idle, too?), vacuum reading at idle, condition of any of the plugs you removed (they can be your best barometer for engine condition), and any other abnormal symptoms you might experience.
But begin by completing your plug change first.
Thread Starter
Senior Member
Joined: Jun 2002
Posts: 595
Likes: 0
From: Schaumburg, Illinois
Engine: slowtacular L03 305
Transmission: slushem 700r4
OK well i would have don the #5 plug but its a pain to get too with a sensor (i think o2) right there and the air crap so i just left if for sometime when i had the time, same with the wires, i have them i just need the time to change them. Anyway here is a bit more info. It is something i can hear and feel it is not just the tach (which started doing that so i started listening and feeling). It seems to happen only once the car has warmed up past the 160 mark and my t-stat has opened. It seems to be about 50rpm swing and isn't noticeable while driveing only when idleing, especially in park or neutral. It is also noticeable if you put some gas to it and rev it up a bit and hold. After a few seconds it will start to bounce a bit both visually and audibly. I have not put in a came or anything (also does not perform like the previouse owner has done it or sound like it for that matter). I will try to update you once i get the plug and wires changed. It doesn't seem to be effecting anything at this point but if it doesn't change after the plug and wires i want to know if this is a real problem or just a quirk (i need this car to last atleast 3years to get me through college). I am like a said (or maybe haven't i don't know 12 hour night shifts makes it a bit hard to remember somedays) i am still trying despereatly to do it right and clean and replace everything that should have been now and correctly before i get to school and really have no money.
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