Anyone familiar with a 4AC?!?

QuiteDrifty
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Anyone familiar with a 4AC?!?

Postby QuiteDrifty » Sat Feb 08, 2014 1:49 am

Ok so long story short, A few weeks ago I picked up an 86 Corolla SR5 Automatic. Completely stock with a rebuilt engine. Drove it 3 hours home with no issues. Next day drove it a few miles here and there, drove phenomenally. Next day, it was -30 degrees here in Milwaukee. Previous owner put too much water mixed in with the coolant and it froze. Basically, after a very short drive, it welded cylinder 1 connecting rod to crankshaft. Sourced a new motor, used the block and put everything else from the original engine back on.

Day 1 it had a high idle. messed with the carburetor and ignition timing a little bit and got it idling and running great. Even managed to get a couple donuts in my work's parking lot before a manager came out :lol:

Day 2 I go to recheck everything and make sure it's ready to be registered and drivable. However that wasn't the case. Ran horrible, had no power, and smelt alot of fuel. Pulled each spark plug wire and found cylinder 1 was not firing in any way. As in absolutely no change in rpms.

Here's where it gets weird. I checked compression, I have 150 across the board. Fuel, well I can smell it, see it, and when I cranked it with the spark plug out I tasted it (best to not put your face right into the opening). From flooding cylinder 1 my oil seems like its 90% gas. Swapped spark plugs and wires around with no change. I determined it has to be the cap and rotor, because anything before that would cause a multiple misfire, not just one specific cylinder.

Cap and rotor did nothing. Same issue. Pulled valve cover and verified valves opening and closing. Checked and confirmed valve clearance was in spec. i was thinking perhaps exhaust runner plugged? Pulled off EGR tube (which connects to number 1 runner) and ran it. Still same issue.

I'm at a point where it has to be something stupid with these engines, that hopefully someone has run across? This car is supposed to be my daily, and it's been making me regret buying it every since. Help me out PLEASE if you know anything.

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Six1ohrollaz
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Re: Anyone familiar with a 4AC?!?

Postby Six1ohrollaz » Sat Feb 08, 2014 8:16 am

Make sure your timing is correct the points on the dizzy and the markings on the damper/crank pulley! Not sure of the degree off hand but make sure both points coincide.... Sounds too me like a timing issue esp if u smell of unburnt fuel...
current cars
85 corolla GT-S hb
81 corolla 2dr
after 12 TE/AE corollas this is what it's come down too

meifert
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Re: Anyone familiar with a 4AC?!?

Postby meifert » Sat Feb 08, 2014 10:18 am

Sounds like ignition. Most like a bad distributor
1984 Corolla SR5.....banana on wheels
Buddy Club Spec 2 Over axle, T3 Test Pipe, T3 Bomber Bar, T3 Ultimate Rear Brace, Enkei Apache 2 wheels, (Weber carb and Cam not installed)

Cheap, good or fast.....pick two.

QuiteDrifty
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Re: Anyone familiar with a 4AC?!?

Postby QuiteDrifty » Sat Feb 08, 2014 11:29 am

Whether it was ignition timing or a bad distributor, wouldn't it be causing a multiple miss?

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QuiteDrifty
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Re: Anyone familiar with a 4AC?!?

Postby QuiteDrifty » Mon Feb 10, 2014 3:55 pm

So I re checked cam timing and ignition timing. Both are spot on. Any other ideas? Getting pretty desperate here. If not fixed by this week its gonna be outta here

meifert
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Re: Anyone familiar with a 4AC?!?

Postby meifert » Mon Feb 10, 2014 4:32 pm

Cracked piston, bad rings? Did you check those?
1984 Corolla SR5.....banana on wheels
Buddy Club Spec 2 Over axle, T3 Test Pipe, T3 Bomber Bar, T3 Ultimate Rear Brace, Enkei Apache 2 wheels, (Weber carb and Cam not installed)

Cheap, good or fast.....pick two.

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SR85DET
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Anyone familiar with a 4AC?!?

Postby SR85DET » Fri Feb 27, 2015 6:05 pm

I'm reviving this! Any luck on the issue at hand?
I just bought a 86 SR5 with a 4AC and cylinder number 1 is not firing.
I can put a timing light on it and the light flashes, I swapped plugs and the problem still occurs only on cylinder number 1. I have not checked compression yet which I will do Tom. I found this thread interesting since OP had good compression. Is there anything odd about the design of the 4AC that you could have good compression and ignition but a blockage or no fuel?

Clouds
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Re: Anyone familiar with a 4AC?!?

Postby Clouds » Sat Feb 28, 2015 6:48 pm

SR85DET wrote:I'm reviving this! Any luck on the issue at hand?
I just bought a 86 SR5 with a 4AC and cylinder number 1 is not firing.
I can put a timing light on it and the light flashes, I swapped plugs and the problem still occurs only on cylinder number 1. I have not checked compression yet which I will do Tom. I found this thread interesting since OP had good compression. Is there anything odd about the design of the 4AC that you could have good compression and ignition but a blockage or no fuel?

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