Luna4
Sometime the fuel pressure leaks down went he engine is turned off for a couple hours or more. If that happens the engine may be difficult to start later. Try turning on the ignition switch for a couple seconds allowing the fuel pump to build a little pressure, THEN crank the engine. See if it makes any difference.
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∙ 2011-09-12 07:50:44How do u fix a misfire
You need three things, spark, fuel and compression. If you have replaced EVERYTHING spark related and fuel related including injectors, I would do a compression check next, you may have a valve problem.
did you changed your thermostat? You MUST keep around 195 degree thermostat in the vehicle at ALL TIMES due to the computer system. The ignition module usually gets hot due to corroded electrical connections at the ignition module and or the module is HEAT SENSITIVE and needs to be replaced. (plug wires) Ignition misfire can produce a variety of driveability symptoms including hard starting, rough idle, hesitation....
Manufacturer Contrl Ignition System or misfire.
Misfire is caused when a cylinder doesn't ignite its fuel mixture. Suspect a bad plug, coil, or wire. This will not be caused by a mass airflow sensor, that can cause a rough idle or bad fuel economy, but will not cause an individual cylinder to misfire. Driving with a continuous misfire condition will eventually destroy your catalytic converter. If your check engine light is flashing you are doing serious damage to your cat converter.
There are numerous things that can cause a misfire, see related questions below.
i have 1989 GrandAm Pontiac 2.5 engine misfire when under pressure when driving over 69mph or sitting still accelerating
How long since last tune-up and compression check? Fouled plugs or dirty valve seats (even a burnt vavle) will cause misfire and lack of acceleration (power).
check wire routing,order, or if replace is needed, after that check compression, head gasket,or crack in head.
This may be a misfire caused by a low fuel pressure.
check for low fuel pressure (its critical) with guage on schraeder valve on fuel pipe on rear of engine in cab drivers side , should be around 55psi
Google for 'misfire'.
try changing the cap and rotor
There are a few things that can cause a misfire in a car. Some of these would be oil in the fuel system, spark plugs going bad, or spark plug cables needed to be adjusted or replaced.
Ignition module.
Were the spark plug wires replaced? Even a pinhole in a plug wire can leak enough spark to cause a misfire. Try swapping that wire with another similar length wire from another plug and see where the misfire is then. If the misfire moves to the new cylinder or ceases completely, you'll know the wire was bad.
change the fuel pressure regulator ,i had the same problem on my silverado 2000. that fixed the misfire.