Flooded Engine...easily

[CMB]

New to the forum and Tercels, but have other Toys. Here is the story if anyone cares, if not, just skip to the flooding problem. I bought the car from a dealership in Portland, who picked it up from auction. Got the title and realized it is a 1 owner! I was pretty stoked! 228,000 mi. Sticker says timing belt done at 139,000 back in 1994. It ran pretty rough...low power and would not hold an idle. My wife gave me a hard time when I told here that I just bought a car that died at every stop light during the test drive. I assured her I could fix it, figuring it was an EGR valve stuck open or a carb that needed rebuilt. I got home and started really going over the engine, and it wasn't long before I noticed one of the spark plug wires was not connected to the dizzy cap! I popped it on and viola! It runs great. I also replaced the dry cracked hose from carb base to HIC valve. Idle still was a little low and rough, but I was happily surprised to see it held an idle at 400 rpm, roughly half of spec. I turned the idle speed screw about 1/8 of a turn, which brought up to 800 rpm. Everything was well and I went to bed like a grinning fool.

Flooding:
Next day, after long day at work I wanted to take the terc for another drive. It wouldn't start. I pumped and pumped away at the accel pedal and cranked away...nothing. Next day, I went to look into it. It had spark. it had compression. Looked through the carb into the manifold, and I could see a pool of gas sloshing around as I rocked on the car. I guess all that pumping was doing something. So I removed the spark plugs cranked on the engine for a while to air it out. Put new NGK plugs in and it started right up. The odd thing is that once it was fully warmed up, the idle was down to 600rpm, so I adjusted back up to 800. Now I just need to change the oil, which it needed anyway.

I guess I am curious about...1)how easily these engines can flood. Is that common, or might I have an issue? BTW, fuel at proper level in float bowl.
2)do I need to worry about damage to coil from engine running for who knows how long with a plug wire off the cap?

Thanks!

[takza]

Use some carb cleaner and then some light oil on the choke? Make sure it is working right.

[CMB]

It definitely has a flooding problem. Same thing happened this morning when I went to start it. Tried starting it without touching the pedal and it just cranked away.

I pulled the carb off, making sure to take plenty of pictures of vac house routing. Sure enough the carb base gasket was soaked with fuel. I am not a carb expert, I have rebuilt one other Aisin carb and that was on my 85 land cruiser. This seems to have similar layout, but electric choke on the tercel is new to me. The electric choke seemed to be working properly though. I am working on cleaning things up now and I have a couple of things that are suspect.

The little yellow VSV between the carb base and the CB (choke breaker?) does not seam to allow air to be pushed or sucked through either direction. Can anyone provide more detail on testing this valve? Or provide thought on weather this would cause the observed symptoms.

The two wires that go into the carburetor heat shield seem to lead to a collar around the primary opening. This looks like it is damaged. Let me try posting a pic. Any thought, or info on this would be appreciated.

[CMB]

Well I figured out what that collar is in the heat shield. It is the Cold mixture Heater and is under the Emission Systems under Auxiliary Systems. I am a little concerned about the damage to it though I don't think this would have resulted in the hard start/flooding I have been seeing. I need to replace it or just unplug it and tap the ruptered aluminum back in place. I am not sure what would cause the failure on this CMH. Any thoughts?

The "jet" vac valve above might be working after all. I pulled a vacuum on it and it slowly lets down, which makes sense for the application.

So other suspects...Some passages were dirty and I have cleaned these up the best I can without having access to compressed air. The AAP diaphragm looked good, but I need to check the check valve balls. There was fuel sludge underneath the throttle shaft on the heat shield and general fuel in places, but still not sure what would have caused flooding.

Question: If the auto choke was not working properly, and kept the car from starting on first couple of cranks, would fuel accumulate in intake from continued cranking. That is, does the fuel pump, and carb continue to squirt fuel into the carb primary when cranking, if the accel pedal is not pressed?

[Petros]

you should only pump the pedal two or three times when you start it, more and you risk flooding. There is no way for excess fuel to get into the carb by just cranking, sounds like something is not correct. If float level is correct I do not know what else can cause this.

I seem to recall someone finding fuel in one of the vac lines coming from one of the diaphragms;. It was ruptured. It is normal btw, to have standing fuel in the intake manifold when it still cold (right after start up), but not during normal warm operation.

[CMB]

I finished rebuilding the carb today with NAPA rebuild kit. Just got it all back together and it started up after a few cranks got fuel to the float bowl. Ran smooth at high idle about 2.5. I was watching the choke throttle to make sure choke breaker and choke opener were operating correctly. When the idle started to climb further into about 3 then 4 grand. I turned it off. Checked the float level and it is high above the sight glass. noticed a bit of fuel sitting on top of the secondary throttle valve. I drained the float bowl and walked away for the night.

I had adjusted the float to error on the low side of the middle of the sight glass. So I am thinking the new need valve is not seating properly. Also, the old needle seat had a filter built in to the inlet side, the Napa rebuild lit seat does not have filter. This is making me worry about debris blocking the needle valve from closing.

Any tricks for getting a needle valve to seat properly. I plan to got out in the morning and have my wife turn the key while I tap on the carb air horn above the float valve. Any other tricks?

[4wdchico]

If your carb has the black foam float in it, I always replace those when installing a carb kit. Old foam floats can get soaked with gas and not apply enough force to reliably close the needle and seat set.

[4wdchico]

If your carb has the black foam float in it, I always replace those when installing a carb kit. in your situation I might have just pulled the top off the carb and slapped a new float in it w/o installing the kit. Old foam floats can get soaked with gas and not apply enough force to reliably close the needle and seat set.

[Petros]

It sounds like the float valve is not working correctly. Remove the float and put in a can of gasoline, if it floats it is fine. They can get saturated, but not very often. Also, with the top of the carb off you can check function of needle valve by gently blowing into the fuel inlet (use a short length of clean fuel line and just use your breath pressure), than lift the float until it closes off the air supply. If it takes more than a gentle lifting of the float needle valve is not seating.

clean out the inlet with carb cleaner spray. Usually particles large enough to stop the needle valve from seating can not get past the fuel filter.

[4wdchico]

Sorry Petros, but I'm going to have to disagree with you here. Since floats don't go from the right weight to sinking in gas in a short period of time, tossing it in gas and saying it is good if does not end up on the bottom of the container does not equal a valid diagnostic test.

Check this link out: http://www.autozone.com/autozone/parts/ ... 37903_1434_

It gives the weight of the OEM float as 7 grams. My guess is that your float weighs more than 7 grams and that it will still float when placed in a container of gas. It will just be not as buoyant as a new one that weighs 7g. Less buoyant equals less closing force against the needle valve.

The notes on the link: *** Caution *** over time, the float will retain gas and cause the vehicle to flood. replacing the float is recommended when rebuilding the carburetor. *** Carburetor floats are sold separately ***

[CMB]

Got the needle to seat. Before I decided to pull the top of the carb, I wanted to try the tapping trick. I had my wife come out and start the car. The bowl was drained form the night before. I tapped on the top of the carb just above the float valve with the handle of a large screwdriver while she cranked the fuel into the bowl. I watched the fuel level come into view and settle right at the lower limit of the sight glass. Right were I was aiming for. I tuned up the idle, fast idle and TP per FSM, adjusted the timing to about 8 degrees before tdc, and readjusted idle etc. The factory plug for fuel mixture is still on the carb and I left it that way. Have driven it around all day and it runs great. A little bit of vibration/roughness when idling at 800 rpm, like what had been noticed at lower rpms before rebuild.

After rebuilding the carb, I have the ignition system on the list next. The vacuum advance did not seam to work, when I applied vacuum to either diaphragm the timing did not change. I plugged whichever diaphragm I was not applying vacuum too. Is there something I am missing? The car did not hesitate or ping at higher speeds while driving around today.

[4wdchico]

Got the needle to seat. Before I decided to pull the top of the carb, I wanted to try the tapping trick. I had my wife come out and start the car. The bowl was drained form the night before. I tapped on the top of the carb just above the float valve with the handle of a large screwdriver while she cranked the fuel into the bowl. I watched the fuel level come into view and settle right at the lower limit of the sight glass. Right were I was aiming for. I tuned up the idle, fast idle and TP per FSM, adjusted the timing to about 8 degrees before tdc, and readjusted idle etc. The factory plug for fuel mixture is still on the carb and I left it that way. Have driven it around all day and it runs great. A little bit of vibration/roughness when idling at 800 rpm, like what had been noticed at lower rpms before rebuild.

After rebuilding the carb, I have the ignition system on the list next. The vacuum advance did not seam to work, when I applied vacuum to either diaphragm the timing did not change. I plugged whichever diaphragm I was not applying vacuum too. Is there something I am missing? The car did not hesitate or ping at higher speeds while driving around today.

Good deal on the fuel level.

To test the vac advance do not plug the diaphragm not having vac applied to it, doing this would somewhat hinder the tested diaphragm from moving the timing, provided both diaphragms can hold vac. Test both diaphragms and make sure they both will hold an applied vac for a 60-90 seconds.

The plate in the distributor that the trigger unit is mounted on does not pivot on a single pin as most points/trigger plates do in response to movement applied by the vacuum adv assembly. It rotates on a bunch of ball bearings arranged in an annular contact orientation on it's outside diameter. It is a good design when it is new, however after 25+ years the grease that the individual balls are packed with can harden and interfere with the rotation of the trigger mounting plate. I have had good luck removing the trigger plate & bearing assy. from the dizzy and then removing the trigger from it. I strongly suggest that you do not mess with the tiny sheet metal clips that hold the trigger plate's bearing assy together, just wash/flush out the old dirty hardened grease with your solvent of choice and then carefully apply a light viscosity grease back around the ball bearings with a fine tip needle applicator.

Of course, once you have pulled the trigger plate, it is the perfect time to clean up and re-grease the mechanical advance mechanism also.

If you end up needing a new vac advance unit Standard Motor Products p/n VC360 is the OE Nippon Denso unit. Last time I priced the VC360, Amazon had the best price.

If both your mechanical and vac ignition advance systems are sticky, pretty likely, you will be amazed how much better your motor will run once you have both systems working smoothly.

[Petros]

you do not need the vac advance for it to run well. What it does is advance the timing when at a part load condition (like on a hwy cruise speed) to improve the part throttle economy. So your hwy fuel economy will improve when it is working, but it will not be noticeable much if it works or not. If you mechanical advance is not working it will have a large effect on how it drives, that should be corrected.

I have found that usually just spraying light oil down inside the distributor and working the plate and the mechanical advance usually allows it to rotate. But as 4wdChico points out, sometimes it has to be disassembled and cleaned properly. I have also found that most of the vac advance diaphragms on these cars are usually shot (I go through the wrecking yard checking them and usually less than one in four are working).

Good point on the solid carb floats 4wdChico. When I took high school auto shop the method to check if the float was good was to shake it and listen, they were hollow little brass floats and you could hear the fuel splash around inside of it. I have not seen a brass carb float for many years.

[CMB]

This great info! I can't wait to get into the distributor next weekend! I think vacuum advance is shot in my case. If I remember correctly, I tried applying vac to either diaphragm with and without the other one plugged. Would this lead to a vacuum leak if both distributor diaphragms are shot?

After the distributor overhaul lite, I will be tackling valves and timing belt. Sticker on the timing cover says timing belt was done last at 139,000 in 94. It has 228,000 now. I was thinking of going with Toyota on the belt, but considering Napa if price difference is substantial. Also, is the belt tensioner typically replaced along with belt?

I checked compression and it was 120-130 on first 5-6 compression strokes and 150 psi for 2-4 and 145 for 1 after about 8-9 strokes. Seems good to me but I haven't yet looked at the FSM specs.

[dlb]

your compression readings sound good.

not to change the topic but if you're preparing the car for being roadworthy be sure to remove the sway bar and take a look at the ends that sit through the control arms. they are really prone to severe corrosion and some members have even had them snap while driving, which is pretty catastrophic. the new bushings and metal collar that sit on the sway bar end are expensive but crucial when resurrecting one of these beasts. call me paranoid but i hate to think of something horrible happening to your sway bar and wrecking and the work you put into the engine.

this link has some good info and photos on this topic: http://www.tercel4wd.com/forums/viewtop ... 45&p=20478

i digress. back to your carb/dizzy advance/timing belt talk!