Dparr2ndgen

Greetings all!

About a month ago my 4runner decided to vomit the radiator fan all throughout the engine compartment (rookie negligence on my part.) since I've only had the rig about 2 months I decided it was time to pull apart the front of the motor and do the timing belt, water pump and tensioners. Today I finally finished buttoning the rig back up. I thought that the new belt and correct installation may have helped straighten out some sluggishness but that is not the case.

Here are the symptoms:

1. Complete lack of power when set at 10 degrees btdc. I know the timing belt is not off a tooth as I checked it and rechecked it before buttoning up the motor.
2. Motor doesn't want to run above 3500-4k rpms. Feels like it's maxing out the revs although it doesn't redline until just over 6k.
3. Horrible mileage. Roughly 9mpg.
4 Stumbling. A quick blip of the throttle at low rpms and the motor tides to die.

My attempts at solutions thus far:
1. I went ahead and advanced the timing to where it "feels" right. I was getting great power, motor revs up into the 5k range with a very snappy throttle, vehicle feels great with no pinging or detonation. The problem is that it takes roughly 30 degrees advance timing to get those effects.
2. I checked distributor to make sure it's pointed at cylinder 1 at top dead center when installing belt, and it was. So I don't think the dizzy is off a tooth. So far I have replaced plugs, cap and wires.

Any opinions/ ideas on what it could be? Please let me know of I can provide more info, I appreciate your time.
Dylan
BTW I'm driving a 91 3VZE powered 4wd runner mated to an r150. Bought her beat up and battered at scrap prices and just looking to get her as "normal" as possible.

Dylan

RSR

Vacuum issue from cut or disconnected vacuum line. Wiring issue from cut wiring. Busted sensor from impact or wiring...

Unfortunately, there's a lot that could be wrong.

Dparr2ndgen

Gave a call to a mechanic friend and he suggested that the crank pulley had failed. He said the outer ring is prone to slip in reference to the inner one, since it is 20+ years old and only held together by some sort of bonding agent to the rubber. Popped a new crank pulley in today, and the marks were definitely off. Have it running much better now at 15 degrees of advance, so not completely out of the woods. But moving in the right direction. Electrical seems okay for the time being, so I will start focusing in vacuum lines and EGR (I know there are faults with both systems currently) we shall see what happens

Dparr2ndgen

Update:

Changed crank pulley, along with fusible link and some ground wires. Alternator also checked out bad so popped in a reman. Adjusted TPS sensor (not as hard as instructions make it seem, it was misaligned.) then when pulling TB I realized the fresh air intake hose has some major cracks. Popped in a new hose, and sure enough, had to reset timing at 10 degrees and runs like a champ! Idle set to 750 rpm, and plenty of pep in the motor (my daily is a vg33e frontier, just as anemic as the 3-slow.) needless to say I ak a happy camper, thanks for the help!

scope103

Thanks for the update. As RSR (and others) point out, those symptoms can be caused by a lot of things; nice to have specific examples of some of them.

rworegon

Those pesky vacuum leaks on the air intake hose strike again. Yup, been there myself.
Thanks for posting up the fix.