22re Stumble and Stall (1 Viewer)

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Joined
Jan 2, 2017
Threads
10
Messages
60
Location
Norfolk, Va
1986 4runner 22re. Used for off road only.

In June what ended up being a broken fuel injector plug led me down the road to replace the following before I found it:
-Intake boot
-EGR Delete (to simplify troubleshooting)
-fuel injectors
-TPS (from LCE and calibrated per 4crawler)
-coil pack
-fuel filter
-all new vacuum lines

Ran great for a 4 days weekend outing and ran great when parked. Go out a few weeks after and start it up and it still ran great. Have a trip next weekend so I figured with 2 weeks to spare I should take care of the oil pan leak.

So I pulled the oil pan and found peices of a timing chain. Pulled the valve cover to inspect the chain and it's all there. Must have been part of a previous repair I figure. Get it all back together and it runs like total crap. So I start racking my brain

--20psi vacuum
-replaced PVC and grommet
-40psi fuel pressure
-pulled each plug wire 1 by 1 and each one evenly wanted to kill the motor
-with jumpered timing is +5 degrees
-no CEL
-all grounds are connected

Will idle with the diagnostic port jumpered but won't rev, without the port jumped it'll start and stumble and die. Sometimes it'll go longer than others.

Everything is basically new, and I didn't touch crap when I did my repair. I'm in day 3 of scratching my head and reading
 
usually, that is EGR failing open from chunks in valve. Since it is off the truck now... Maybe distrib got pushed up out of seat on accident, and not lined up w pickup now?

Oil pressure gone?
 
Have you looked at the Idle Air Control Valve?

Have you looked at your AFM to make sure the flap is working inside?
 
Sold (pretty much gave away, actually) a nice Benz many years ago because one day for no reason it refused to start. Next owner spent a great deal of time and found the problem- dizzy timing was off.. or the car had "jumped time" as we say around here.
 
usually, that is EGR failing open from chunks in valve. Since it is off the truck now... Maybe distrib got pushed up out of seat on accident, and not lined up w pickup now?

Oil pressure gone?

Wouldn't it fail to time correctly? Timing is steady and adjusts when I move the dizzy with the bolt loosened. I did that as a sanity check today

Oil light is not on, but I don't have an oil pressure gauge
 
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Sold (pretty much gave away, actually) a nice Benz many years ago because one day for no reason it refused to start. Next owner spent a great deal of time and found the problem- dizzy timing was off.. or the car had "jumped time" as we say around here.

Like I said I don't think I would be able to dial in timing if it jumped a tooth. Plus I only rotated the motor a few times by hand to check the timing chain between running great and current
 
Have you looked at the Idle Air Control Valve?

Have you looked at your AFM to make sure the flap is working inside?

Flap works because I can here is slam shut when it abruptly stalls and t he fuel pump works as is. I have not tested it because it wasn't touches between running great and not, like not even touched haha.

Now the idle air controller I have not. Im not sure why that would cause my issue. Rock solid idle with the diagnostic port jumpered.

I'm just having such a hard time with this because I didn't touch anything !!!! I pulles the oil pan and slapped some ultra black on it, and pulled the valve cover to inspect
 
You say the CEL is not on, but have you checked for codes? Not all errors turn on the light.
 
So I pulled the oil pan and found peices of a timing chain. Pulled the valve cover to inspect the chain and it's all there.

This is likely your problem. There is an old saying that the last thing fixed will be the next thing to break. If it ran fine before you pulled the oil pan and rocker arm cover, then you messed something up putting it back together. Do you have AC? Did you reverse the vacuum lines on the VSV? If so you will hear the vacuum leak (BTDT). Check the connection to the AFM. Did you knock out one of the half-moons putting the cover back on? Also, check the rubber connections to the throttle body and AFM. You might have mugged those and they crack easy.
 
This is likely your problem. There is an old saying that the last thing fixed will be the next thing to break. If it ran fine before you pulled the oil pan and rocker arm cover, then you messed something up putting it back together. Do you have AC? Did you reverse the vacuum lines on the VSV? If so you will hear the vacuum leak (BTDT). Check the connection to the AFM. Did you knock out one of the half-moons putting the cover back on? Also, check the rubber connections to the throttle body and AFM. You might have mugged those and they crack easy.

Thats where I've been trying to retrace my steps but scratching my head. Half moons? Not sure what you're referring too. No AC, the idle up valve is completely capped. Intake hoses are good, I checked that first because that was my problem last time (can't fool me twice haha)
 
Half moons? Not sure what you're referring too.

Here ya go. There is one at the front, and one at the back. Sometimes the one at the back either sticks to the rocker arm cover and falls out, or it gets knocked loose putting the cover back on.

halfmoons-sm.jpg
 
Well crap man, I didn't even know those existed. I would have 100% noticed the front one, but the back... That would allow unmetered air into PVC causing a lean condition. Wish I was home right now to check that
 
It does sound like a massive vacuum leak, just like if you try to run the engine without the 710 cap installed.

BTW, you are supposed to put a dab of RTV/FIPG/bubble gum on the ends of the half-moons right before dropping the cover back on. No need to schmear them all up though, they make a good seal in the half-circle cutouts in the head (as long as they are in good condition).
 
So the half Moons are in place. I was able to get it to run much better with my thumb over the front vacuum hose both at the plenum and vavle cover. I'm guessing I'm just cheating the air fuel mixture richer by removing air.

That would lead me to my valve cover being leaky so I pulled it and put RTV on it. It's better but not great. I just can't believe it could cause a lean condition being a little leaky (no oil escapes)

I have two wild ideas... Bare with me.

1) What is that hose on the front of the valve cover for? Can I remove it... Or put a PCV valve on it too to limit the air coming into it?

2) I've never done the AFM trick that richens the mixture. I have long tube headers and an intake. People swear by that mod, and if I need a little richening that might do the trick.
 

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