Question:

        no codes, runs reasonably good cold, warm too, just sometimes (quite often) really rough irritating idle, no stall, just bloody rough, new plugs, air filter, compression exactly 155 on all cylinders, lots of injector cleaner through it, a long time ago, cleaned the mass airflow sensor with brake cleaner, still at a loss. 425 kms in the city on a tank of fuel, 550 on the highway, 375 towing the boat. any answrs? thanx in advance

Response:

Check for vacuum leak or PCV valve.  How old are the spark plug wires?

> no codes, runs reasonably good cold, warm too, just sometimes > (quite often) really rough irritating idle, no stall, just bloody > rough, new plugs, air filter, compression exactly 155 on all > cylinders, lots of injector cleaner through it, a long time ago, > cleaned the mass airflow sensor with brake cleaner, still at a loss. > 425 kms in the city on a tank of fuel, 550 on the highway, 375 towing > the boat. any answrs? thanx in advance

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Response:

how bout the fuel filter ?   a clogged filter will cause a rough idle, and / or stalling…

– Hide quoted text — Show quoted text -> no codes, runs reasonably good cold, warm too, just sometimes > (quite often) really rough irritating idle, no stall, just bloody > rough, new plugs, air filter, compression exactly 155 on all > cylinders, lots of injector cleaner through it, a long time ago, > cleaned the mass airflow sensor with brake cleaner, still at a loss. > 425 kms in the city on a tank of fuel, 550 on the highway, 375 towing > the boat. any answrs? thanx in advance

Response:

wires are new, also used my little tester on em to make sure firing all down the line. Fuel filter changed 2 years ago when i bought it. would the filaments on the maf need cleaning after only a year? I use carb cleaner on them, should I use a more powerful solvent? Thanx guys – Hide quoted text — Show quoted text ->how bout the fuel filter ?   a clogged filter will cause a rough idle, and / >or stalling… > no codes, runs reasonably good cold, warm too, just sometimes > (quite often) really rough irritating idle, no stall, just bloody > rough, new plugs, air filter, compression exactly 155 on all > cylinders, lots of injector cleaner through it, a long time ago, > cleaned the mass airflow sensor with brake cleaner, still at a loss. > 425 kms in the city on a tank of fuel, 550 on the highway, 375 towing > the boat. any answrs? thanx in advance

Response:

Clean the IAC valve. – Hide quoted text — Show quoted text ->wires are new, also used my little tester on em to make sure firing >all down the line. Fuel filter changed 2 years ago when i bought it. >would the filaments on the maf need cleaning after only a year? >I use carb cleaner on them, should I use a more powerful solvent? >Thanx guys >how bout the fuel filter ?   a clogged filter will cause a rough idle, and / >or stalling… >> no codes, runs reasonably good cold, warm too, just sometimes >> (quite often) really rough irritating idle, no stall, just bloody >> rough, new plugs, air filter, compression exactly 155 on all >> cylinders, lots of injector cleaner through it, a long time ago, >> cleaned the mass airflow sensor with brake cleaner, still at a loss. >> 425 kms in the city on a tank of fuel, 550 on the highway, 375 towing >> the boat. any answrs? thanx in advance

Response:

I’ve heard carb cleaner may be too strong for cleaning the  MAS.  It could cause damage. Use an electrical cleaner that does not leave any residue. http://www.tccoa.com/articles/intake/mafclean.html

– Hide quoted text — Show quoted text -> wires are new, also used my little tester on em to make sure firing > all down the line. Fuel filter changed 2 years ago when i bought it. > would the filaments on the maf need cleaning after only a year? > I use carb cleaner on them, should I use a more powerful solvent? > Thanx guys >how bout the fuel filter ?   a clogged filter will cause a rough idle, and / >or stalling… >> no codes, runs reasonably good cold, warm too, just sometimes >> (quite often) really rough irritating idle, no stall, just bloody >> rough, new plugs, air filter, compression exactly 155 on all >> cylinders, lots of injector cleaner through it, a long time ago, >> cleaned the mass airflow sensor with brake cleaner, still at a loss. >> 425 kms in the city on a tank of fuel, 550 on the highway, 375 towing >> the boat. any answrs? thanx in advance

Response: