when ever you get into unexplained symptoms the answer remains the same....in every case,.... you drop back to the basics and do a few tests ignition spark should be bright blue and impressive, if its, weak,narrow, yellow or red theres a problem so research the cause, verify the coil and voltage
find the cause,
read the codes, and follow the FACTORY SHOP MANUAL INFO
having a few basic meters,gauges etc. helps
MULTI METER
INFRARED TEMP GUN
TIMING LIGHT
COMPRESSION GAUGE
PRESSURE/VACUUM GAUGE
is it mechanical?
look for broken parts, loose connections, leaky hoses
are the CATS clogged or the O2 sensors faulty
check the compression in all cylinders
re-adjust the valves
look for vacume leaks
look for loose serpentine belts
look for cooling system problems
check the trans fluid level and condition
check oil and fuel levels
check the rear differentials fluid level and condition
check the engines oil level and condition
check the brake fluid level and condition
change the filters
check the throttle body is opening completely
verify the TPS and IAC are set correctly, and use some carb/throttle body cleaner to clean up the TB.
what are the engines oil pressure, fuel pressure and cooling system temps?
if somethings wrong theres usually symtoms that point to the source!
IS it electrical?
verify the MAT, MAP, and or MAF sensors are working correctly
verify the coolant temp sensor and knock sensor are working
set the ignition timing
install new plugs with a .045 gap
verify the O2 sensors ok
look for loose grounds, on the engine,gauges,battery
check the battery voltage
check the fuel pump and relays
use a V.O.M. to verify plug wire resistance
check/replace the distrib cap.
VERIFY ALL SENSORS and FUSES and CONNECTIONS are ok, verify the voltage on the systems correct
IS it fuel related
verify the pressure and flow
verify the injectors are functioning correctly
read the old plugs
use a ir temp gun to verify exhaust temps
throw a couple cans of injector cleaner and 8 oz of MARVEL MYSTERY OIL into a fresh tank of fuel, it can clean out lots of minor varnish in the system
partly clogged injectors, or injectors running at over 80% duty cycle tend to reduce power and increase emissions
90% of your problems will be found just running thru the check list and following the shop manual suggestions, yes diagnostic software , and owning a scanner is a very good idea!
find the cause,
read the codes, and follow the FACTORY SHOP MANUAL INFO
having a few basic meters,gauges etc. helps
MULTI METER
INFRARED TEMP GUN
TIMING LIGHT
COMPRESSION GAUGE
PRESSURE/VACUUM GAUGE
is it mechanical?
look for broken parts, loose connections, leaky hoses
are the CATS clogged or the O2 sensors faulty
check the compression in all cylinders
re-adjust the valves
look for vacume leaks
look for loose serpentine belts
look for cooling system problems
check the trans fluid level and condition
check oil and fuel levels
check the rear differentials fluid level and condition
check the engines oil level and condition
check the brake fluid level and condition
change the filters
check the throttle body is opening completely
verify the TPS and IAC are set correctly, and use some carb/throttle body cleaner to clean up the TB.
what are the engines oil pressure, fuel pressure and cooling system temps?
if somethings wrong theres usually symtoms that point to the source!
IS it electrical?
verify the MAT, MAP, and or MAF sensors are working correctly
verify the coolant temp sensor and knock sensor are working
set the ignition timing
install new plugs with a .045 gap
verify the O2 sensors ok
look for loose grounds, on the engine,gauges,battery
check the battery voltage
check the fuel pump and relays
use a V.O.M. to verify plug wire resistance
check/replace the distrib cap.
VERIFY ALL SENSORS and FUSES and CONNECTIONS are ok, verify the voltage on the systems correct
IS it fuel related
verify the pressure and flow
verify the injectors are functioning correctly
read the old plugs
use a ir temp gun to verify exhaust temps
throw a couple cans of injector cleaner and 8 oz of MARVEL MYSTERY OIL into a fresh tank of fuel, it can clean out lots of minor varnish in the system
partly clogged injectors, or injectors running at over 80% duty cycle tend to reduce power and increase emissions
90% of your problems will be found just running thru the check list and following the shop manual suggestions, yes diagnostic software , and owning a scanner is a very good idea!
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