ic3ss

Hey guys, I have two things to ask about.

I've read in the Haines manual about the O2 sensor on carburated 22R, but damned if I can find it. It should be on the exhaust between collector and the cat. I've gone hand over hand down the whole length and it's just not there. I didn't know that a carburator would need a sensor, but the manual says it should be there.

Any ideas?

I blew the head gasket and am in the process of putting it back together. Before this happened, it had a constant lack of power. Plugs/wires/cap-rotor/fuel filter/air filter all have been replaced. Cat has had the guts taken and the can re-installed, and a straight glass pack installed replacing the old muffler. The timing has been adjusted more times than I can remember with a timing light.

When I took the head off, I noticed a hole on the intake side of the head, and sharing the intake maniforld gasket, just behind the intake manifold where something was bolted with three bolts (I don't know what it is). But when it was removed, the hole in the head was completely plugged with black exhaust buildup. Could this be causing my power issue?

rowdy235

carb'd motors don't have 02 sensors. Only EFI.

That black exhaust buildup hole was for the egr (I think), I know EGR's have been known to cause a loss of power, that may very well have been your issue.

Hope this helps.

stock87

Wrong, some carbed trucks do have O2 sensors, mine does. They usually have them in the manifold itself, if they have them at all. That said, they don't (can't) do much on the motor though. The majority of your problems are going to come from improper fuel/air mixture. That much buildup in the EGR passages means you were probably running rich, blowing a lot of soot through the exhaust. I'd check the AAP diaphragm to see if it is blown, since that will let waaaay more fuel than is needed into the engine. It's the circular aluminum cover with the 3 roughly equally spaced mounting screws on the lower left of the side of the carb that faces the engine.

If that isn't the problem, poke around the carb. I'd wager the float level is wrong or a jet is loose or something of that nature.

Let us know what you find.

myyota

My 84 4Runner is carbed and has an 02 sensor, its mounted in the exhaust manifold.

ic3ss

So much for standardization. O.k. I'm going to clean out that hole as best I can, I think it wraps around inside the back of the head, so I'm sure I won't be able to get it all. Maybe I'll blow it out with air.

I'm going to get the timing/water/oil pump on today, and I'll clean up that hole after that.

I'll keep updating.

Yodaforce

For those of you with a carb AND an O2, tell me where the computer is at and where it hooks up to the carb. I'm beginning to smell something very fishy here, cause I have never, ever, heard of a computerized, carbed 22R.

Yodaforce

And by the way, if the hole on your EGR port is clogged with carbon, chances are the tube that bolts up to it is too.

anotherjeff

I believe the signal from an O2 sensor on a carbed engine, is utilized (by the ECU) in the operation of the Air Injection System. The ECU is in the usual place, the passenger kick panel. The ECU has NO control over the carburetor.

If the OP still has the head off the engine; remove the rear plate from the head and clean out the EGR passageway thoroughly,

ic3ss

I'm putting the head on, and I'm wondering if there is a pattern that the head bolts must be tightened in. I know the torque spec is 58ft/lbs but is there a specific pattern to tighten them in?

rowdy235

yes there is, look it up in a service manual