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6th Generation (1988-1992) Specific discussion of the AE92

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Old 03-24-2009, 11:52 PM   #1 (permalink)
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4AF terrible mileage and smells like gas

Hi all, I just found these forums when I was searching for info about my car and boy am I glad I did. I didn't know people still loved these little ae92s! I bought mine a few years ago because it was economical and quickly fell in love with it. Mine was single owner, garage kept, by an old lady and her sister that barely ever drove it. When I picked up my '89 Corolla DLX it only had 80,000 miles on it, still had the original dealer license plate frame, new owner welcome kit, and the dealership window-sticker was even in the glovebox!

It's been running great until just recently, my mileage suddenly dropped to about 17-18 mpg and my car just smells like gas. Cylinders 1 and 2 closest to the passenger side are missing because their getting flooded with gas.

I tried taking this to a mechanic but they looked at it for about 30 seconds then told me to pay $250 to rebuild my carburetor. I'm willing to rebuild it myself or buy a used one, but I don't actually think it's the carburetor. My car only has 130,00 miles on it and that seems too early for the carburetor to fail.

Symptoms:
1. I think I can hear hissing from a vacuum leak. I need to track it down and fix it. I'm planning to replace all the vacuum hoses.
2. My car has hard starting troubles when it's cold. Nothing bad, but from reading this board it makes me think my choke is sticking.

What else could it be? I read in another thread that it might be the auxiliary acceleration pump leaking fuel..? I'll be posting updates in this thread as I work on my car.

Last edited by Shakahs; 03-25-2009 at 12:08 AM.
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Old 03-25-2009, 12:04 AM   #2 (permalink)
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Check the wires, sparks and stuff. Don't see why two cylinders would be flooded leaving the other two fine.

It may be the aux. fuel pump on the carb (I had that problem before). When I hit around 40MPH (dunno RPM, cuz I didn't have a tach at the time), it would feel like I have a rev limiter and wouldn't go faster. So my dad's friend came over and disconnected the vaccuum that controlled it, ran like new (somewhat).

About your vaccuum leak, if it's hard to find, just take a can of aerosol carb cleaner, aerosol brake cleaner or similar and spray it around different areas around the carb. If the engine speeds up slighty, the vaccuum is in that vicinity... Now if you have vaccuum leak, maybe that's causing your excessive fuel in the chambers.
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Old 03-25-2009, 12:36 AM   #3 (permalink)
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take pics of what was disconnected... I HAVE THE SAME PROBLEM! 6k and it start putting and crap. It's also running pretty rich. Need to e-test it so an easy fix would be great!
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Old 03-25-2009, 02:58 AM   #4 (permalink)
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AE92

Ok, don't mind the carburetor being out of the car (that's my second carb I went through). About the disconnection, my dad's friend also said the car really don't need it. So maybe it's there to cause shit problems, dunno.

The photo is taken from the rear-right (firewall) side of the carb. The little guy I'm pointing at... Cut the rubber vaccuum line that go to it (some drops of fuel may come out) and plug the openings with screws or something. Then take it for a test run. Hope it works!

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Old 03-25-2009, 03:44 AM   #5 (permalink)
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Well I just found a carb kit on ebay for less than $20 (including shipping) so I bought it even though I'm not sure my carb is the problem. I'll rebuild this weekend and I figure the worst it can do is help.
It's Tomco Inc kit #5392C, which I got here
http://cgi.ebay.com/ebaymotors/ws/eB...m=280000477611
after matching up my carburetor number to tomco's kit number in the pdf files here
http://www.tomco-inc.com/PDFCatalogs.aspx
I'm just hoping it includes the float, because Tomco's catalog lists the kit and the float separately, and I can't tell from the product image on eBay whether it's in the bag or not.
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Old 04-09-2009, 02:22 AM   #6 (permalink)
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Thanks alot!

Before going ahead with rebuilding my carb I checked the choke and float level, then unplugged the acceleration pump and that fixed my problems. Fuel economy is back to normal and my car doesn't smell like gas anymore. My acceleration has taken a big, noticeable, hit but I'm fine with that.
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Old 04-15-2009, 10:41 AM   #7 (permalink)
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Quote:
Originally Posted by Shakahs View Post
then unplugged the acceleration pump and that fixed my problems. Fuel economy is back to normal
Could you describe in detail how to unplug acceleration pump? I have a terrible mileage too)
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Old 04-15-2009, 03:57 PM   #8 (permalink)
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That aux accellerator pump diaphram is probably the weakest part of the Toyota carburetors, but is an easy fix.
I have had it go bad on two toyotas, and the symptoms are the same, bad milage and #1 cylinder misfiring at times or fouling out completely.
The vacuum line for the AAP goes to #1 intake tract, so when the diaphram leaks, raw gas gets sucked from the float bowl into that cylinder. Replacing the diaphram is easy, if you can get it. Sometimes you have to buy the complete carb rebuild kit to get that little diaphram. Not everybody stocked it, when I had carby cars.
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Old 04-15-2009, 08:02 PM   #9 (permalink)
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Your carburetor is an Aisin carburetor so it won't likely need rebuilding or a rebuild kit for 30 years or 500,000 miles

All it needs is a new auxillary accelerator pump diaphragm which any Toyota dealer can get you for about $30 or
you get can 28% off at www.1sttoyotaparts.com A new diaphragm will end the gas flooding of cyl#1 and also restore
good acceleration and fuel economy.

But if power and fuel economy are not fully restored then it could mean your catalytic converted became overheated and internally melted / clogged during the time you were driving around with the engine guzzling gas. Or the oxygen sensor could have been ruined too causing the fuel mixture to be too rich.
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Old 04-15-2009, 11:14 PM   #10 (permalink)
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Thanks for really useful advices)
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