Won't Idle
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Joined: Oct 2007
Posts: 87
Likes: 1
From: Davenport Iowa
Won't Idle
My 75 has always ran very well the motor is stock L-48 with headers and all pollution crap removed. Went on 70 mile trip a week ago and ran perfect when we left but when we got home would not idle in drive and exhaust smelled very rich. First thought was bad gas so added a can of seafoam and ran it wot 2 or 3 times on a 10 mile trip yesterday still won't idle. Has Q-jet #7045222 which should be original carb. All vacuum hoses are attached every thing looks okay any ideas on what could be the problem.
Burning Brakes
Joined: Oct 2006
Posts: 1,006
Likes: 28
From: Lutz Florida
Possible vacuum leak. Make sure none of the hoses are split or came loose. Don't forget to check the small pieces of vacuum hose that connect the hard line at the manifold and at the vacuum modulator on the other end at the transmission (if your car is automatic).
Booster diaphragm or the booster check valve may be leaking vacuum. If the booster is bad you'll have hard pedal and poor, to no, idle.
Can be a number of other things too.
Booster diaphragm or the booster check valve may be leaking vacuum. If the booster is bad you'll have hard pedal and poor, to no, idle.
Can be a number of other things too.
Former Vendor
Joined: Apr 2009
Posts: 766
Likes: 3
From: Charlotte North Carolina 704-394-5150
Possible bad fuel filter in the carb causing trash to keep the needle and seat open. When it is idling (rough as you say) CAREFULLY look down in the front section of the carb where the choke plate is. If you see fuel dripping you have trash in the needle and seat. One trick is to carefully rev the engine high (3000+rpm's) and quickly cover the front portion of the carb with a light damp towel long enough to almost stall the engine. Remove the towel and keep the engine running. Re-rev it again and when it is on high rpm's again do it again. Then see if the vacuum pulled the trash through and now the fuel is not dripping. I have had to do this several times until it stops dripping. Make sure that you are holding onto the towel the entire time and not just throw it on the carb. If that does not do it or if it does and the problem keeps happening over and over, you have trash in the bowl of the carb and need to get it cleaned out and replace the fuel filter in the carb along with other fuel system parts that may be causing rust or other debris to enter the system from within.
"DUB"
"DUB"
