my 88 van is injected but I just followed the rubber line from the manifold to the charcoal canister. i found that it transfers from rubber to a hard line, then back to rubber then into the canister. from there to the fuel tank
the line from the manifold , meets the hard line and i can see it if I look behind the passenger side front tire. I dont know if yours is similar but cars have had these charcoal canisters for a long time and many feel its unnecessary garbage. they basically carry old fuel vapors so the rubber is susceptible to rot. It wasn't good thick hose like used to carry fuel, mine was very thin stuff.
I just thought maybe you could check if that line exists and maybe plug it off or fix it in case its the cause of a vacuum leak. yours has carbs but might still have a leaky line too , if it has charcoal canister.
my van has a lot of similar issues but the design isn't; close enough to gather a lot from..
I keep getting these garbage distributor Caps that don;t have ether brass or copper electrodes. they use aluminum or pot metal instead. cheap buggers...
they sure don't last long before those electrodes are all pitted and gunked up.
i permanently ran a tiny LED from my distributor primary to under my dash so if my distributor does start to miss pulses I can see it. that way of the module craps out I shoudl be able to easily spot a no spark condition because then the primary won't be seeing pulses. I only really need to see it if it won't start but then its nice to jet see without eeding to connect a test lamp or check for spark at the plugs. or use a timing light.
all it does is helps me narrow down the troubleshooting at a glance. when runing it just glows.
if your distributor has a sensor in it, I'd check that and any wire connections. what can happen with distributors is the seals wear , O rings etc. it might be a reed switch or a hall sensor, something similar, check its wires and you can always give it a spray, I think some are horeshoe shaped and have a tiny window about the size of a pin head.. some work by magnetism, maybe less affected. if it is a C shaped sensor and the flag passes between and happens to get close thenI believe that can cover the hole if there is one.. a balst of pressurized air and alcohol might clean it. don't go explode yourself.
then crank case fumes start barfing oil up the stem and it gets into the distributor , then attacks wiring and sensors. that light coat of oil fumes can cause weird intermittent electrical failures.. its a general statement , not specific info.
I had lots of squealing issues ad in my van found a proportioning valve that dripped ocasionally it was wetting h belt i a van the brake Master is quite near the belt. and its on the master cylinder. . get even one drop of oil on that belt and it takes off squeling and once it squeals , it looks fine but if you compare and look close all thse little grooves get wider and the ribs get narrower. areful if you check or change your oil not to drip on the belt !
my take is that although your alternator may be fine if the battery is weak then it may still keep trying to charge a lot.
a low battery will cause a lot of drag and that can initiate the problems. as then the alternator requires a lot more power.
i tried a bunch of different tensioners. I found on i had had a very shallow bolt and that made changin ght ebelt hard, my wrench would slip off because the Nut is too shallow , the one on the idler bolt.
ther is no easy way to increase tension I did try to make that pin on the back of it, exccentric to load the thing up a little more. another way is to change it so the spring applies tension but it can be locked in place rather than spring loaded. then you can put more tension on the belt.
I think it only takes about a half minute of squealing and the belt is fried, after that it loks ok but is not you can try different belts, i just changed mine and elliminated the AC then it wraps a bit different. Id actually just made a mistake and ordered the wrong one, but I dont need AC. the one I got is green and one of the more expensive ones.
try making a comparison between a new belt and the one you have and really look close at the width of the ribs and grooves. I think the ribs get thin and then it won't grab. if a V belt gets thin you notice , but with those its hard to see it.
belt dressing sprays, I never had any luck wiht them, you can use alcohol too. it cannot be oily ! that will cause it to slip.
maybe rosin like a violin uses could help , who nows..
if it starts squealing try to charge up the battery, rather than creating slippage , if you can. what could happen is you timker with your vehicle then you go test it but you've had the interior light and things on so the battery is just low. and needs to regain. next you start and the belt is cold and then slips, then the slippage is , well.... exactly the right definition, a " slippery slope."
