I replaced the timing chain in my '88 4Runner 22RE. While trying to remove the vacuum hoses from the 1st and 2nd VSVs (vacuum switch valve) on the valve cover I broke one of the plastic nipples on each where a vacuum hose attaches. I thought I'd fixed them with a small plastic stent, but after everything was back together the 4Runner wouldn't run below 1,500-2,000 rpms. Above 2,000 rpms it runs great, but it smells like it may be running a little rich. I just replaced the 2nd VSV (still waiting for part on front VSV) and no change.
I have a suspicion after I replace the other VSV, nothing's going to change, because I really believe my stents fixed them. I've looked everywhere for another vacuum leak and can find none. My question, if I got the distributor off a little would it cause the current symptoms? Any thoughts are greatly appreciated.

 

Are you absolutely sure you put the timing chain on right and put the distributor back in the way it cam out. Did you mark the dist before you took it out? Hows it run at idle? Did you line up the Bright links on the chains to the marks at their proper places? Cam gear dot a 12'oclock along with bright link. Crank gear dot at 6'oclock along with sec bright link? Intake hose loose or leaking? Any codes?

 

Bright links with each dot on crank and cam at 6 and 12, respectively. Marked distributor; back on same place. Before job 4Runner ran great; idled at 900 rpms, very smooth. Now below 1500 rpms stalls out. No codes and I can not find a leak.
After I had gotten it back together I had a friend rotate the distributor while I kept the engine going at 2000 rpms. No matter where we set the distributor it stalled below 1500 rpms--makes me think it is a vacuum leak. Actually I'm now praying it is a vacuum leak.
I won't do anything radical until I get and replace the other VSV next Tuesday, but I really believe I fixed mine with the little plastic tube stent. The front VSV the dealer ordered was identical to mine in every way except for the electrical connector and valve cover mount. I took a vacuum hose and hooked it to both of the plastic nipples on the new one, sucked and blew. Front nipple no air passed; rear one air passed freely. I then did the same on my "repaired" VSV--exactly same air flow pattern. That's the reason I'm skeptical replacing my front VSV will change anything.

 

If your sure the timing is right then its prob a vac leak. there should not ahve been many vac lines to take off doing the T-chain except the ones of the valve cover... did you put them back into the right places if at all? Older toyotas will attempt to stall if theres a big enough vac leak. If the Pcv valve hose or breather hose going to the valve cover to the intake are leaking and or disconnected the truck will not stay running on its own its to big a leak. I would go over it again for leaks. Is everything connected? You didn't disconnected the coolant temp sesnor or the cold start time switch connectors did you? They are right bellow the Upper rad hose. Is there a check engine light? Air flow meter plugged in?

 

Hoses to your idle air control connected?

 

I labelled everything I disconnected with colored tape and wrote down everything as I did it. No check engine lights. I'll go over all hoses again in the morning. I didn't disconnect coolant temp or cold start switch. Air flow meter was not disconnected and I believe if it was the problem I'd have code 31 flashing on my dash.

 

If you bring the engine around to TDC #1 compression is the Rotor button pointing at the #1 spark plug wire on the dist?

 

I thought so before I buttoned it all back up; however, as soon as I have the new VSV in place and try to run it, if no change I'll be checking that first.

 

Hot damn, I found it !!!!

Went out this morning and checked all the hoses; replaced many of the small vacuum hoses and the one to the PCV. Cut all the covering off wires that had become brittle from the engine heat--no broken wires. I then decided to remove the big air tube connecting the air flow meter and the throttle body. Luckily for me it had some grease on it and I decided to clean it off. When I was cleaning the hard rubber accordion elbow that connects to the throttle body I noticed on the ventral side at the bottom of one of the creases it was cracked. This was really only evident when it was flexed. It is now sealed with metallic duct tape and the 4Runner runs great at all rpms.
My stent repair of the VSV did work after all.