1981 Tercel PCV and Breather tube setup

[marlinh]

Ford has mounted inertia switches that shut off the fuel pump in a collision. I can't believe someone did all that to your car. The mechanical fuel pumps were adequate for these engines. The pressure in the system being 5 psi.

The bolts that hold the air cleaner down are 6mm X 1.0mm (bolt diameter X Thread pitch) Other common sizes are 8mm X 1.25, 10mm X 1.25mm and 12mm X 1.25. Be careful, some SAE threads will start in a bolt hole and then jam. If tightened in anyway, the threads will be damaged.

Good luck.

[Petros]

the factory fuel pumps do not cost much, are available from most auto parts stores, are very reliable and will return your car back to stock. Mounting the pump INSIDE the car is madness. looks like the fuel lines could chaff and cut against the metal edges too, really not a good idea at all.

When I was in high school it was considered a performance mod to install an electric fuel pump and block off the place where the mechanical one goes. It supposedly took less power from the engine, this I think was ignorance since it take the same amount of power to push the fuel with a mechanical pump or with an electric one, and the electric one takes the power out through the fan belt and alternator. If you were tweaking an engine and needed more fuel supplied, that is a different issue of course, but we were too ignorant back than to know why electric pumps were put in, only that "race cars" always had them. Stock car racing course ban electric fuel pumps for the reasons already noted, they keep pumping fuel after a crash.

I would install a stock factory pump, they are reliable and safe, and you will not need more fuel capacity with a 62 hp engine, even if you double the power out put.

[irowiki]

Alright, don't laugh, but could somebody point out the rough location of the mechanical pump? I have a sneaking suspicion it was removed, because I've seen nothing that looks like it.

What is the purpose of the fuel return line? I'm looking at the "fuel tank and lines" diagram in the 1985T4WD.PDF, I can say for sure all the evap stuff has been removed. The Charcoal canister, OVCV/VSV. I'm assuming the steel line used for that is the one that is currently unused.

When I have the wheel off this weekend I'll see what they did to the back.

[Petros]

the fuel pump is behind the carburator at the aft end of the head on the same side as the intake/exhaust manifold. You can see it on the upper left in this picture below, left of the carb (the white bucket is behind it). It bolts to the side of the head, you likely have a blank plate across it, two 12 mm bolts hold it on.

[irowiki]

Yeah, there's a little cover plate held on with two bolts in that location on my engine!

[irowiki]

So I'm confused now. While searching the manual I got on this site for how the vacuum advance is supposed to be hooked up to the distributor (I'll start another topic for that), I found information on the HAI (hot air intake system). The HAI on my Tercel is long gone however.

In the manual It shows a tube going from the air filter (the HIC valve) to the port on the intake manifold.

If that is the case, where are the breather and PCV valves supposed to connect to? On my car I have a tube from the PCV going to the intake manifold and a tube going from the breather into the HIC Valve (as per suggestions here)

The HIC valve supposedly closes above 84 degrees, does that mean the engine stops breathing after that since I have the breather hooked up to the HIC? I could in theory just remove the bolt that I assume has the temp sensor in it from the HIC valve then it could always breathe?

[Petros]

the HIC valve regulates the air intake temperture to keep it in a fairly narrow range. It draw air from around the exhaust manifold and mixes it with the cold air from the breather coming from next to the headlight. The valve is vacuum operated but regulated by the HIC, which monitors the air temp inside the air filter assembly. I do not remember where it draw the vacuum from, but it has to be a constant vac source. I disabled mine so it always draws cold air, cold air is more dense and delivers better fuel efficiency and max power than warm air. Unless you drive around in really really cold weather where carb ice might be a problem, you will not notice if it is working or not. If it is connected incorrectly and acts like a vac leak it will affect drivablity. If you disable it just cap off the vac lines, and disable it in a way so it is always drawing cold air from the inlet plenum.

[irowiki]

Oh, the entire system was removed, there's just a bunch of holes on my air cleaner assembly where the hot/cold flapper valve used to be!

[Petros]

I think I have an extra air cleaner assembly if you want it. Can you post a picture of what you actually have on the car. You do not want any unfiltered air going into your engine, the fine dust in NM will almost certainly wear the rings out fast.

[irowiki]

The filter housing itself is in good shape, and I think it seals just fine.

https://sphotos-a.xx.fbcdn.net/hphotos- ... 0959_n.jpg

I'll take some up to date pictures when I can open the hood without fear of the hood flying away (huge wind storm right now)