OEM carburetor issue

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kitchman
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My tercel:: 1983 2wd tercel hatch back ,1986 SR5

OEM carburetor issue

Post by kitchman »

Hello all,
About a 11/2 years ago I completely rebuilt the stock carb. What I have observed ever since is that if you dare give any more than a tap to the accelerator pedal, to engage the choke, the carb. is rendered into a flooded state and will not start until the gas is sopped up from the intake manifold, a real PITA. I am thinking that this has some thing to do with an adjustment of the accelerator pump linkage?
Thank you in advance
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Petros
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Re: OEM carburetor issue

Post by Petros »

that would not provide enough fuel to cause flooding, something else is wrong. can you see the fuel level in the float bowl sight glass, if the flat allows too much fuel into the bowl, it will spill into the the carb, and flood out. the other thing that might cause flooding is fuel bleeding into the vac system (likely from the AAP) and into the manifold.

something intermal to the carb perhaps did not get installed properly, or is stuck "open" or in a position to cause flooding. The only way to know for sure is to first veryify there is no other cause of excess fuel, it is adjusted properly, and all the vac lines are installed at their proper location, and perhaps try and rebuild it again. USE the factory Service manual procedure for a carb rebuild to check all adjustments, and that all systems are operating properly.
'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)
kitchman
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My tercel:: 1983 2wd tercel hatch back ,1986 SR5

Re: OEM carburetor issue

Post by kitchman »

Thanks for the reply, Leaving for trip Sunday and winter returned so can not do much on this issue for a couple of weeks. Like usual the gas was sopped up and a hair dryer was positioned over the carb. throat It is worthy to note that the inside of the intake manifold remains dry, bone dry such that some starting fluid is used for the initial start. Depressing the gas pedal is causing an excessive amount of fuel to enter the manifold. I checked the sight glass on the fuel bowl and tried shaking the car to get a view of the fuel level but could not. Either it is too low or too high or?
If it were too high wouldn't fuel be entering the intake manifold after the drying process? As I stated, once dry it remains bone dry until the throttle is engaged?
Thanks again
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Petros
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Re: OEM carburetor issue

Post by Petros »

you should see the fuel level in the window on the carb, if not you have to pull the top and adjust the float level. likely the needle valve is gunked up and not allow it to close,and cuasing flooding. It will only flood when the engine is running. usually you can clean it out, and test my gently putting intake pressie on the fuel inlet line (I put a clean hose on it and just blow in it), and lift the float, it should stop the air flow. if you can not clean it out so the float shuts off the fuel supply, it needs to be replaced. you can get a kit at rockauto.com or order one from your local autoparts store. you might be able to jsut buy a needle valve.

while you have the top of the carb off you might clean out the rest of it with carb cleaner. be careful, there are some small passages that have check balls in them that can get blown out while spraying carb clear in the passages ways.
'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)
kitchman
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My tercel:: 1983 2wd tercel hatch back ,1986 SR5

Re: OEM carburetor issue

Post by kitchman »

thanks again for the reply. Still have not had a chance to further explore the problem. In your last message you stated " It will only flood when the engine is running". As I have explained, the flooding occurs before the engine starts and only when the accelerator pedal is depressed more than a mere tap. Most times there is absolutely no problem starting the engine as long as the gas pedal is not pressed.
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Petros
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Re: OEM carburetor issue

Post by Petros »

the only way that would be possible is if your fuel pump, for whatever reason, is over pressuring the fuel system and on first bump, it just sparys out into the carb intake. Seems unlikely. Try this: with the car cold, careful remove the air filter, and with a powerful flash light look down the barrels of the carb, open the choke and than open the throttle and see what happens. if you get a flood of fuel, you need a new float/needle valve for the carb, and/or to check the fuel pressie is not over the specified level (should be only something like 2-3 psi as I recall, but look it up in the FSM).

Are you running the stock fuel pump? If not you likely need to add a fuel pressure regulator.

If your float level is correct in the view window, and the fuel pressure is within spec, than the problem is elsewhere. You may not actually be getting flooding, my project car right now stalls a lot when cold, something is wrong with the cold start system. once warm it works perfectly normal and drives well. So it may be something in else in the cold start system.
'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)
kitchman
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My tercel:: 1983 2wd tercel hatch back ,1986 SR5

Re: OEM carburetor issue

Post by kitchman »

Hello again, sorry was away. The fuel level is at the correct level in the sight glass. Also as I have been stating, when the car will not start the intake manifold has pools of gas. If it were a result of faulty float/needle valve, wouldn't the problem be present all the time and have nothing to do with pressing the accel. pedal? also OT the fsm doesn't have a illustration of the exhaust system piping and still need to know how the piping and muffler is configured for the 86 wagon.
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irowiki
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Re: OEM carburetor issue

Post by irowiki »

I had the factory carb on my 87 with 60k miles, after I rebuilt the engine, when I would try starting it, it puked gas through the two bronze vent tubes, so I swapped it for another carb.

I can sell you a used carb for cheap if you want to play with it?
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)

Site administrator, if something is broken, PM me!

87 Corolla FX16, 105k
94 Jamboree RV (Ford E-350), 90k
95 Camry Wagon, 170k
97 4runner, 275k
kitchman
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My tercel:: 1983 2wd tercel hatch back ,1986 SR5

Re: OEM carburetor issue

Post by kitchman »

Thanks for the reply and offer, but I would like to isolate the problem before throwing any money at it. The carb. was recently rebuilt and therefore has new parts. I still think the problem has some thing to do with an adjustment of the accelerator pump linkage.
xirdneh
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Re: OEM carburetor issue

Post by xirdneh »

I have messed with quite a few carbs on these cars. I have rebuilt them with kits and taken them apart cleaned them out and put back together without kits. Success rate either way is about the same, lucky if 1 out of 3 works right. I have quite a few carbs in a box that are tagged with descriptions of how well they worked. Many different symptoms . some of the best working carbs have come from parted out cars that sat for years to a decade. I did nothing to them and they worked great. I know they had to have had dried out gas residue in them . swapping carbs until I get one that works has become my standard operating procedure. I pick up carbs wherever I can find them. Most I ever paid was 30.00
Love those Tercell 4x4 wagons but they sure suffer from road noise.
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Petros
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Re: OEM carburetor issue

Post by Petros »

often the rebuilt carbs are trouble some if not done properly. I have found used good carbs will often work better than rebuilt ones. Do not assume if it was rebuilt that is was done properly, they are sensitive to lots of assembly details. If you get flooding, it is likely something wrong with the carb. could be a bad AAP diaphragm, leaky needle valve, internal leakage, over pressured fuel pump (though that would show a high level in the view window). There is no adjustment to the accelerator pump, it either works, or it does not, there is no adjustment. Also, since it was apart, double check the routing of all the vacuum lines, they often get mixed up (even by repair shops). it could also cause flooding.
'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)
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irowiki
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Re: OEM carburetor issue

Post by irowiki »

Yup, one of my Tercels had a freshly "rebuilt" carb and it was totally crap junk. Replaced it with a junkyard carb and it ran SO much better.
Former Tercel Enthusiast (not a practical family car anymore but they still have a place in my heart)

Site administrator, if something is broken, PM me!

87 Corolla FX16, 105k
94 Jamboree RV (Ford E-350), 90k
95 Camry Wagon, 170k
97 4runner, 275k
kitchman
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My tercel:: 1983 2wd tercel hatch back ,1986 SR5

Re: OEM carburetor issue

Post by kitchman »

Just realized that I didn't report about the final outcome, sorry. As it turned out the carb. was not the problem, but rather the ignition coil was defective. The occasions where the engine would not start and gas pooled in the intake manifold was a result of the coil not always producing spark and as a result the amount of fuel not being ignited would build up creating a flooded condition. After replacing the coil, cap and rotor, problem solved!
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