Topic: 22-RE running rich

[4Runninfun]

I have an '85 4Runner with EFI. and it's running rich... REAL rich. i have pulled and cleaned the MAF using the MAF cleaner from Checker, I also bought a new o2 sensor. When i pulled the old o2 sensor it was covered with black soot.  Neither of which helped at all. I have also replaced most of the vacuum lines with nice shiny new silicone hoses. new plugs and wires recently too. So before i pull any hair out any thoughts?

[emsvitil]

Is the check engine light on?

If it's running that rich, it should throw a code because it's not in closed loop mode.

How's your oil consumption?    It could be burning oil.....

[4Runninfun [OP]]

No CEL it is buring some oil but i wouldn't appear to be that bad. IE i don't add much between oil changes. ALSO one more thing to add, it doesn't seam to have all the power it should. Could low compression cause all/part of this?

[jimbo74]

low compression could cause a rich condition, as its allowing oil to get into the cylinder somehow, either bad head, headgasket, bloyby from bad rings or valves

on a gas engine, it is not right to be burning oil.. sure some may be wear and tear, and that can excuse it, but oil shouldnt be in the chambers

[4Runninfun [OP]]

Well i just came across the engine compression and leakdown thread.

The good news... it's not the head or gasket as i just replaced both of those. (engnbldr head, 268 cam, arp studs, new HG.)

The bad news... I didn't know the factory specs for compression. I measured mine at 120psi. Did the math and came up with VERY low compression figures. I just figured i did the math wrong. now looking at the above thread and what is average for these motors...CRAP!

This is EXTREMELY frustraiting as i just spent ~$1500 putting in the new head, studs, vacuum lines, clutch as well as other misc stuff. This past time was the 3rd time in two years tearing the motor down. I've had such bad luck with this motor. I'm really not sure if i want to spend the money to fix it this time.

[jimbo74]

may not be upper end at all, its a general rule that the cyls should be within 10 psi of each other....

could be bad rings.... things go bad after 25+ years

[4Runninfun [OP]]

I can attribute almost all the problems i've had with this rig to the previous owner. Almost everything that i have found wrong or that has broken were things that were messed with prior to me owning it. for example last time i had the motor torn down i found a broken exhaust valve guide. Took it down to have it machined out and replaced, turns out ALL the exhaust valve guides were the WRONG ones! So given the past history of this truck, i'm willing to bet that when this guy bored it 50 over, and put the new pistons and rings in he screwed that up as well.

ALSO... in addition reading the Compression post where the guy talks about when his trucks sounded like a diesel, he found out he spun a bearing. well guess what my motor sounds like?  

[jimbo74]

i thought i spun a bearing when i sucked a valve guide in my #2

the 22r sounds like a diesel anyways, they are loud....

i tried adjusting my valves before, they got louder after i adjusted them....

[knobbie]

I had the same problem with mine.  Couldn't pass inspection.  After the o2 sensor, maf clean, and new catalytic converter I checked the ignition coil.  Can't remember which now, but one of them was bad, either the primary or secondary.  Truck ran ok with a bad coil but I guess it has a hard time cooking all the fuel when you don't get a good spark.

Anyway, it was a combination of all these things that worked for me.

[emsvitil]

Cracked, bad seals, warped flanges at the exhaust manifold.

Lets air into exhaust.

O2 sensor thinks engine is running lean, and ECU compensates ..................