microserf
Member
hi
i am a car newbie here, my ride is a 1991 Mitsubishi Galant GSX, non turbo, DOHC. Recently I am having some rough idling upon starting the engine cold. The RPM drops to about 500 and if i try to drive it, i have to press on the gas pedal to keep the idle up to 1000, and it drives pretty unsteady. But once the engine warms up in about 20 to 30 min. It drives smoothly as if nothing is wrong. But the fumes out of my tail pipe smells like gasoline. and i have horrible gas mileage ( about 3 km per liter )
I went to a repair shop, they cleaned the IAC and throttle, and they suggest that my MAF needs replacement. So i got myself a surplus MAF (we dont have many OEM parts here specially for older models), which the mechanic assured me is working fine. After the installation, i still get the rough idling on cold starts, but the mechanic suggested a workaround - pumping the gas pedal 4 to 5 times before cranking the key ( after the check engine light went off). When i do this, the engine starts fine, reving at 1000 but it reverts back to rough idling when i dont do this. As before the car is fine when the engine is warm.
my question is
1. by pumping my gas pedal - what does it do to "cure" the rough idling? what condition does it create, so that the rough idling on cold starts will not happen
2. Did it cure my horrible gas mileage, since it has just been 3 days,i had no chance to confirm if my gas mileage has improved. i filled my car to full tank and will measure my gas consumption
thanks in advance
i am a car newbie here, my ride is a 1991 Mitsubishi Galant GSX, non turbo, DOHC. Recently I am having some rough idling upon starting the engine cold. The RPM drops to about 500 and if i try to drive it, i have to press on the gas pedal to keep the idle up to 1000, and it drives pretty unsteady. But once the engine warms up in about 20 to 30 min. It drives smoothly as if nothing is wrong. But the fumes out of my tail pipe smells like gasoline. and i have horrible gas mileage ( about 3 km per liter )
I went to a repair shop, they cleaned the IAC and throttle, and they suggest that my MAF needs replacement. So i got myself a surplus MAF (we dont have many OEM parts here specially for older models), which the mechanic assured me is working fine. After the installation, i still get the rough idling on cold starts, but the mechanic suggested a workaround - pumping the gas pedal 4 to 5 times before cranking the key ( after the check engine light went off). When i do this, the engine starts fine, reving at 1000 but it reverts back to rough idling when i dont do this. As before the car is fine when the engine is warm.
my question is
1. by pumping my gas pedal - what does it do to "cure" the rough idling? what condition does it create, so that the rough idling on cold starts will not happen
2. Did it cure my horrible gas mileage, since it has just been 3 days,i had no chance to confirm if my gas mileage has improved. i filled my car to full tank and will measure my gas consumption
thanks in advance