Intermittent Misfire
#1
Intermittent Misfire
I need suggestions... So I'm getting very frequent, but still not consistent, misfires at stop lights. I also have no guts when accelerating. Pretty much fine when engine's cold and when cruising.
I've changed:
-plugs
-plug wires
-Cleaned EGR valve
-PCV valve
-Fuel filter
-Fuel Pump (checked for any rust/crap in tank area)
-Gone down fuel lines and any wiring I could see for breaks or melting etc.
Every one of those things needed changing or cleaning.. but it's still happening and I'm running out of ideas. Any suggestions?
I've changed:
-plugs
-plug wires
-Cleaned EGR valve
-PCV valve
-Fuel filter
-Fuel Pump (checked for any rust/crap in tank area)
-Gone down fuel lines and any wiring I could see for breaks or melting etc.
Every one of those things needed changing or cleaning.. but it's still happening and I'm running out of ideas. Any suggestions?
#3
Like Mr. Dragon said, check for codes, first. It could save you a tone of time and money. If you don't have a truck that will give you codes, it's time to do some good old fashion trouble shootin' and mechanicin'.
Could be any one of a number of other things...
Does your truck have a distributor? If so, Check the rotor, be sure it's getting a steady spark at each terminal.
No Distributor? Verify that each coil pack is firing every time.
Does the miss happen at idle and/or at speed? Under load, or not?
The last time I had an intermittent miss in one of my trucks it turned out to be a weak valve spring. Occasionally the valve wouldn't completely seal.
Could be any one of a number of other things...
Does your truck have a distributor? If so, Check the rotor, be sure it's getting a steady spark at each terminal.
No Distributor? Verify that each coil pack is firing every time.
Does the miss happen at idle and/or at speed? Under load, or not?
The last time I had an intermittent miss in one of my trucks it turned out to be a weak valve spring. Occasionally the valve wouldn't completely seal.
#4
1991 C1500 2x4... 305ci 5.0L V8 103000miles
haha never owned a vehicle new enough for codes, I guess I should take a look under the steering column!
yes to distributor... I shall check rotor and cap and I guess ignition pack.
It doesn't happen at idle in park or neutral... only in drive with the brake on
haha never owned a vehicle new enough for codes, I guess I should take a look under the steering column!
yes to distributor... I shall check rotor and cap and I guess ignition pack.
It doesn't happen at idle in park or neutral... only in drive with the brake on
#6
take a jumper wire to your obd1 port hook it to the a&b ports turn the truck on but not started
the service engine light will flash and then will flash 1-2 that means the computers working
then any other code will follow in a serious of numurous flashes
the service engine light will flash and then will flash 1-2 that means the computers working
then any other code will follow in a serious of numurous flashes
#8
but yes and 02 sensor will casue your truck to run like its about to die out on ya when you need it the most
#10
I couldn't find one... In my last vehicle (80 camaro) there was one... this has an advance wire connected near the firewall. A week ago I checked the flywheel pull (has none, thank God) and the timing and had to remove the wire to do so... Is this wire the replacement for the advance vacuum hose?