Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and beginning April 20th, 2021 (Eastern Time) the Yahoo Answers website will be in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
97 cavalier z24 misfires cyl. 1 and 3 but has compression spark and fuel?
i own a 1997 chevy cavalier z24 2.4L and i took it into my autos class to do a starter draw test on it. my instructors said that most GM vehicles have a program on the vehicle where if you hold down the gas pedal, the engine will not start but just crank. ever since i did that, my engine misfires on cylinders 1 and 3. all my instructors were trying to figure out what went wrong and how to fix it but no one knew. compression came up to 155lbs. we tested for spark and all 4 cylinders have clean spark and we tested the computer for fuel injection and the computer is putting off signals and gas shoots out the tailpipe so there is fuel. the weird thing is that cylinders 1 and 4, 2 and 3, are companions but its cylinders 1 and 3 that are misfiring. we also ohmed out the coil packs and they came out perfect. anyone know what to do?
7 Answers
- bobwebLv 71 decade agoFavorite Answer
Try the propane test where you have a propane wand you move about the engine looking for a vaccum leak.
"A faster technique for finding intake manifold vacuum leaks is to get a bottle of propane and attach a length of rubber hose to the gas valve. Open the valve so you have a steady flow of gas. Then hold the hose near suspected leak points while the engine is idling. If there is a leak, propane will be siphoned in through the leak. The resulting "correction" in the engine's air/fuel ratio should cause a noticeable change in idle speed and/or smoothness (Note: on engines with computerized idle speed control, disconnect the idle speed control motor first)."
Source(s): http://www.aa1car.com/library/vacleak.htm - NaughtumsLv 71 decade ago
Swap the spark plugs from 1 to 2. If the misfire follows the plug you have your answer. Looks like the only thing you have not checked yet.
- dodge manLv 71 decade ago
the thing i would check first would be the plugs for those cylinders its possible it got plugs wet and shorted them out,and they will show to fire but not under compression,secondly it could have stumped the computer on it,try removing the battery cable to see if it will help erase it,i wish i had it in the shop,that would be a good one to work on,id scan the computer and see if any trouble codes appear on it,that one even has me stumped though ,the only thing i would have did differently would have been to disconnect the coil pack do it couldn't get any fire,this way their would have not been any chance of it damaging anything,good luck finding it,i want know what it is when you find it,
Source(s): been a certified mechanic for 38 yrs now. - How do you think about the answers? You can sign in to vote the answer.
- ?Lv 45 years ago
What did the spark plug from that cylinder look like. feels like you're turning out to be oil fouling from a foul oil ring or valve seal on that cylinder. a minimum of I gave you a authentic looking answer really of i do not understand or maybe wires once you stated you engine don't have wires it has police officials. do not understand why some human beings even answer with foolishness.
- Michael BLv 61 decade ago
Have you looked into new plug wires? Random misfires can often be traced to these...
- Anonymous1 decade ago
recheck the firing order maybe you put the wires on wrong by accident the check relays and fuses
