Bones_inst
Member
- Joined
- May 1, 2011
- Messages
- 5
- Vehicle Year
- 1992
- Transmission
- Automatic
Truck has no power and misses badly at idle. If it idles for a long time it will clean itself up, but seems to be overfueling. Check engine light is on, very hard starting.
Engine is a 4.0 l V6.
The truck wouldn't start at all this morning, so I tried to pull the engine codes.
I put the jumper in to to pull the engine codes with the key on but not running and waited 5 min without having the system enter into the test mode. I took the cover off of the ecm and bumped it with a pair of pliers, 30 seconds later the truck would go into test mode and give all engine codes. Shows 185 and 186 code, performed clean on mass air sensor with electrical mass air sensor cleaner.
Tested the vacume, and it is within spec, the compression is from 120 to 150, the fuel pressure is operating as per manual.
The truck fired right up. No codes no issues. I turned it off, and attempted a restart, same issue. I tried to run a diagnostic on it again and would not initialize, after a few min I bumped the ecm with a pair of pliers again and like before it went into test mode again and gave the same errors, I assume because they have not yet been cleared, and after test, truck would fire up again.
Cleared codes, road tested, engine runs well until put under load.... 1/2 throttle, then throws more codes, 181, 185, 186. Book says 181 - fuel system at lean adaptive limit at part throttle, system lean. 185 mass air flow lower than expected. 186 injector pulse width higher than expected.
On the bright side, the engine is now running better at an idle, but i suspect that a cold start might be bad again will find out tomorrow morning, will post update. Started good this morning but no power under load and throws engine codes.
Won't start after work, won't recognize that the jumper is installed on the ECM, I suspect that the ECM is failed and that the MAS is damaged too.
Is the ecm failing? Do I need to change the MASS air sensor and O2 sensor? Am I missing something??
Engine is a 4.0 l V6.
The truck wouldn't start at all this morning, so I tried to pull the engine codes.
I put the jumper in to to pull the engine codes with the key on but not running and waited 5 min without having the system enter into the test mode. I took the cover off of the ecm and bumped it with a pair of pliers, 30 seconds later the truck would go into test mode and give all engine codes. Shows 185 and 186 code, performed clean on mass air sensor with electrical mass air sensor cleaner.
Tested the vacume, and it is within spec, the compression is from 120 to 150, the fuel pressure is operating as per manual.
The truck fired right up. No codes no issues. I turned it off, and attempted a restart, same issue. I tried to run a diagnostic on it again and would not initialize, after a few min I bumped the ecm with a pair of pliers again and like before it went into test mode again and gave the same errors, I assume because they have not yet been cleared, and after test, truck would fire up again.
Cleared codes, road tested, engine runs well until put under load.... 1/2 throttle, then throws more codes, 181, 185, 186. Book says 181 - fuel system at lean adaptive limit at part throttle, system lean. 185 mass air flow lower than expected. 186 injector pulse width higher than expected.
On the bright side, the engine is now running better at an idle, but i suspect that a cold start might be bad again will find out tomorrow morning, will post update. Started good this morning but no power under load and throws engine codes.
Won't start after work, won't recognize that the jumper is installed on the ECM, I suspect that the ECM is failed and that the MAS is damaged too.
Is the ecm failing? Do I need to change the MASS air sensor and O2 sensor? Am I missing something??
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