1984 Euro Tercel 4WD Wagon

Post about yourself, your Tercel, or your Tercel projects in here, share pictures of your Tercel, or post trip threads!
User avatar
Highest Ranking Member
Posts: 11761
Joined: Sun Jan 28, 2007 6:31 pm
My tercel:: '84 Tercel4wd w/extensive mods
Location: Arlington WA USA

Re: 1984 Euro Tercel 4WD Wagon

Post by Petros »

if you pull the vac line from the AAP you should not see fuel leaking out of the vac line, but it could be wet with fuel. The engine vacuum sucks the fuel into the intake manifold, but when not running it can not flow through the line. though you may not see much fuel when you pull off the line, so it is a simple test to cap it off and run without the AAP engaged.

But if you pull the vac line and it is wet with fuel, the AAP is ruptured, and needs to be replaced. this can be done without removing the carb, but a quick fix is to just cap off the vac lines on both ends.

I think the need for it is that the fuel system is designed to run fairly lean, even during cold start. Running lean means it will cough and sputter when you try to accelerate when it needs more fuel. The AAP it is to eliminate the flat spot that occurs with a cold engine. there is not enough of the fuel vaporizing when it is cold, so extra fuel is required to make it so it will not have the flat spot. After warm up, more of the fuel enters the combustion chamber as a vapor allowing for more efficient and complete combustion.
'87 Tercel 4wd SR5 (current engine swap project)
'84 Tercel 4wd (daily driver, with on going mods)
'92 Mazda MPV 4wd (wife's daily driver)
'85 Tercel 4wd DLX auto(daughter's daily driver)
'01 Honda Civic (other daughter's daily driver)
Post Reply