Topic: 81 22r poor running w/ video

[spuds015]

got a 81 pickup 22r carb. while driving truck tried to hit a hill and the truck just bogged with no power. 3rd gear can only get to 25mph. there was a weird whistling noise and it just wont rev past 1/2 throttle. it ran for fine for 50 miles before it suddenly happened. got it home. whistling noise was the exhaust manifold loose, tightened it, no change. compression is at 150psi on all cylinders spark plugs were questionable but replaced those with no change. its idles perfect. its a cali truck but it has the high altitude compensation valve. carb was rebuilt less then 5k miles ago. i haven't torn into the carb to check yet. here is the video to show whats happening. don't have a timing light at the moment to check the advance. both sides of the advancer hold vacuum and the mechanism moves

http://s63.photobucket.com/albums/h141/Spuds_015/?action=view&current=WP_000016.mp4

[79coyotefrg]

and this happened all of a sudden??  have you tried moving the distributor a little to see if it helps??  it sounds like its horribly out of time.

[spuds015 [OP]]

checked timing as per manual and it is correct idle is at 15* and with the vacuum lienes unplugged its at 8*. however did find the AAP diaphragm was already cracked and bad enough to be sucking gas out the vacuum hose. replaced diaphragm and still no good. we have even applied vacuum to the advancer w/ a vauum pump and it still doesnt help. im leaning towards a bad carb job/bad parts.however it does die when we spray brake cleaner at the vacuum port for the pcv valve. another thing ive found is when i rev it and manually apply the accelerator pump it dies or if i cover the throat of the carb by had and reving it past 1/4 throttle it tries to die and it spits hella gas out the carb and the engine shakes hella bad once it tries to get to wide open

[79coyotefrg]

putting you hand over the carb just chokes it and sucks more gas into the carb.

so did it ever run good with this carb

[spuds015 [OP]]

ran fantastic for like 3 months or 5k miles. my freind has been borrowing it since his truck is down and drives about 60+ miles one way 4 days a week. even the day it happened it was fine for the first 50 miles from sacramento to home. it was very sudden

[spuds015 [OP]]

rebuilt carb today yielding no change. swapped dizzys with my buddy's truck and no change. still dies out and spits gas out the carb. cam still in time, cam chain not loose or damaged. when is vacuum supposed to be applied to the side of the advancer closest to the radiator? i have zero vacuum at all times coming from the HAC valve. float level is at the lowest possible in spec position. is there anything that can make the carb suck too much gas when it gets to the main circuit? seems like a lot of fuel is dumping into the throat once it starts revving up. im just about out of ideas at this point...  bout to roll it off a cliff

[79coyotefrg]

try a different carb

with the crank timing on 0* where is the cam timing mark??

[spuds015 [OP]]

12 o clock. the only thing i can think of is that the carb is bad. unfortunately idk anyone i can just borrow a carb from. mybe a weber would help. or even a 4.3 or 1.9 tdi haha

[spuds015 [OP]]

Problem solved. The flopping exhaust is plugged up somewhere. Took the o2 sensor out and the damned thing ran fine. Next question is: if its the cat can I just run without it without hurting anything besides a few spotted owls?

[Dingman.]

My cat was clogged and i had to take it out until i could afford an aftermarket one years ago.

[spuds015 [OP]]

yup, took the cat off and the guts just started falling out in chunks. i bet it was running too rich from my leaky AAP diaphragm. i gutted it and will see what happens. can anyone tell me what the thermo sensor does on the cat?