Fozz
Newbie
Greetings all! New member here. Currently working on a 1998 GMC K1500 with a 5.0L. Truck was purchased by my dad in 1999 with 17,*** on the clock. I recent purchased it from him and it is currently sitting at 179,***.
Currently I am experiencing a rough idle that is driving me insane. Here are some facts on the situation.
-60K on a rebuilt 5.0L
-New plug wires
-New cap/rotor, but Dist. is suspect, due to a broken ear and oversized machine screw installed. Although it idled fine for many miles with this set up
-No check engine light
-Pulled the plugs with 60K on them when rough idle started. Cylinders 2,4 and 7 were severely fouled. #2 was black and crusty but not wet. #4 was crusty black and tan. #7 was crusty but tan only.
-Replaced with new plugs, idle was improved, but a couple weeks later rough idle was back.
-Cleaned MAF, some improvement, but still rough.
-Ran a compression test, all cylinders were 185-195 PSI
-I have tried running with the MAF unplugged, no change in idle quality noticed.
More information regarding symptoms:
-Truck runs good when the engine is cold.
-Long term fuel trims running -10 to -12 at idle warmed up.
-Truck runs good at all speeds/RPM except idle
-The symptoms are seem to be intermittent, although it never idles perfect. Some days are better than others.
-K&N air filter, which I plan on getting rid of soon.
Currently I am experiencing a rough idle that is driving me insane. Here are some facts on the situation.
-60K on a rebuilt 5.0L
-New plug wires
-New cap/rotor, but Dist. is suspect, due to a broken ear and oversized machine screw installed. Although it idled fine for many miles with this set up
-No check engine light
-Pulled the plugs with 60K on them when rough idle started. Cylinders 2,4 and 7 were severely fouled. #2 was black and crusty but not wet. #4 was crusty black and tan. #7 was crusty but tan only.
-Replaced with new plugs, idle was improved, but a couple weeks later rough idle was back.
-Cleaned MAF, some improvement, but still rough.
-Ran a compression test, all cylinders were 185-195 PSI
-I have tried running with the MAF unplugged, no change in idle quality noticed.
More information regarding symptoms:
-Truck runs good when the engine is cold.
-Long term fuel trims running -10 to -12 at idle warmed up.
-Truck runs good at all speeds/RPM except idle
-The symptoms are seem to be intermittent, although it never idles perfect. Some days are better than others.
-K&N air filter, which I plan on getting rid of soon.