Audrienne

A little background on this truck. Bought it early September from my neighbor, not a DD, but was driven every few days. Bought a rebuild kit for the Aisan carb and dove into Yotatech forums and proceeded to rebuild carb, successfully, also replacing a lot of vacuum hoses that looked old/worn/degraded. We also addressed a few other issues that the truck had (mild tranny leak, new muffler, signal light out, radio short/blowing fuses, etc). The truck ran well for a couple of weeks and I thought I had everything straightened out until this weekend. Saturday, I went across the creek and up a mountain, then bk down the mountain and across the creek (all in L4) and no big splashing of water (in other words, no water in the distributor nor in the snorkel/air intake). On the way back up to the house (switched to H2), I noticed that the idle was getting rough. I threw my husband back in the truck and we ran down to the store. Idle got worse, to the point of me having to power brake (yep, it is a 5 speed) just to keep truck running when switching down gears. As we arrived home, I down shifted to go up our driveway and it died immediately. I was able to start it again and get it into the backyard.

Last night, husband and I ran thru all the vacuum hoses, replacing most of the ones that didn't get replaced when I rebuilt the carb, til I ran outta vac hose. I know it would be best to spray the whole thing with carb cleaner to look for vac leaks, and I plan on doing that when I can get more. I know that vac leaks can occur from the simplest hose to the base of the carb to the brake booster. I also have spent hours and hours pouring over various posts that kinda cover the issue(s) I am having.

We "redneck" tested the idle cut-off solenoid (heard a click when engaging the key). When husband forces the choke closed, it purrs like a kitten. I have to keep my foot on the gas to keep the truck running in neutral. We were going to check the timing (is somewhere around 5 right now from what we can tell), but probably won't until we get this idle issue resolved. None of the screws on the carb have moved since the rebuild. Idle mixture screw has been set to factory specs by me when I initially rebuilt the carb 3+ weeks ago (yep, I drilled out the freeze plug). Gas in sight glass is half way up, where it was initially and where it was after rebuild. No problem at all with fuel flow to carb, from what we can tell. When I rebuilt the carb initially, I drilled out the rivets on the choke cover and removed the diaphragm, rod, and assembly for a thorough cleaning. I reinstalled with provided rivets. However, this evening, I removed those new rivets and opened up the choke again, thinking something was sticking in there. It was clean as a pin, the rod assembly moved smoothly. I made sure that I got the wires (the ones that move with the temperature) back on the arm that moves inside the choke correctly (as I did when I rebuilt the carb) and closed the thing back up (this time with self tapping screws).

The choke opener assembly (the piece that vacuum pulls on to move the arm on the back of the carb that works with the fast idle cam) moves, but seems to move less efficiently (seems to have more drag?) than the throttle positioner assembly (same type of action - vacuum hose pulls to create movement). I have searched and searched for a way to clean the choke opener assembly to no avail. I have also made certain that my rods and cam and follower and all that mess that is on the rear of the carb (throttle body assembly as the carb rebuild paperwork calls it) is all assembled correctly and functioning correctly according to what I could find via yotatech, etc.

I am currently printing a FSM (1400+ pages). I am also aware of the possibility of the vac hoses to the distributor being an issue, but they look to be in good condition.

So, here are my questions: Can the choke opener assembly be cleaned? How do I determine if it is functioning properly and not just "barely?" I plan on getting a tester from my husband to try to test the wire that goes to the choke to see if it is getting current as it should, but he did say that he could "feel" the choke opening when his hand was over the carb, so we think that it is working properly.

I figure while I have the carb off (again) that I would see if y'all could offer further insight that might be something I can address while it is sitting on my table. If not, I will put the carb bk in the truck, hook everything back up, and then hope for the best. My husband will be picking me up more carb cleaner tomorrow and I will disassemble the carb again, blow everything out again, and then reassemble. I will also be spraying anything and everything that has any possibility of having vacuum to see if the idle is affected.

I have an inclination that the BVSV might also be a problem and will likely remove it while I have the carb off. Insight on that would also be appreciated, it seems I have to drop coolant level to take it off of the truck?

The FSM I am printing explains how to test the Choke Opener System (including the Choke Opener Diaphragm/assembly) but in order to follow their directions, I have to be able to ensure that the fast idle cam has released to the 4th step - very difficult to determine as that is all on the back of the carb, towards the cab of the truck when carb is installed...how exactly do u determine it made it to the 4th step if u can't get ur head bk there, much less see what is going on? Basically, I am stuck, frustrated, and very sad. I have always wanted a 22r stick 4x4 and now that I have it, I can't enjoy it! Thanks to all that take the time to respond!

az1320

wow. what a novel. how old are your plug wires and how old are the plugs? as well as check your plugs it will tell you what the motor is doing.

old87yota

First off, Welcome to YotaTech!

I agree with az1320, you did write a novel. For future posts this long, make sections and break up the sections with spaces so the post is easy to read.

Don't get too frustrated. Think of this problem like a fun puzzle. Or that is what I try to do when something doesn't work....

From what you said, you suspect the carburetor or vacuum leaks to be the cause of all of this. This is definitely a real possibility, especially since you just rebuilt the carburetor. I have not done much with my carburetor yet (a carb. rebuild is in my future) so I don't have direct experience with your carburetor questions.

However, don't overlook simpler and potentially unrelated causes too. I would also look at the spark plugs and wires. The plugs may guide you towards the problem if they look abnormal. Some other easy checks would be the battery, corrosion on battery terminals and wires, or damaged wiring. Bad electrical connections can do weird things.

Since you are printing the FSM (a mountain of pages), I would look through the carb. section and look for other possibilities as well.

I wish you the best of luck on this project!

Audrienne

After I posted my "novel," I realized how hard it must be to follow without being broken up, my apologies. I just might go bk and edit it for future readers...

New plugs, new wires, new dist cap and innerds (forgive my ignorance - husband is the distributor guy - I am the carb gal) were installed when I rebuilt the carb in early Sept. I can't pull the plugs bk out to check them myself (I have beaten myself up over the years and just don't have the hand strength that I used to) so I will have to wait for husband to get some time while it is still daylight. Battery connections (not cables) were replaced on Saturday. I also checked all fuses that I could access (under hood and behind kickplate on drivers side at floor) Our local auto parts stores did not have the cables, otherwise we would have replaced those as well. Will continue to shop for some, tho.

I did pull the EGR vacuum modulator this morning and the filter is pretty tired. I will look into cleaning it with some air, but I have a feeling I will be hunting a filter. Right now I am struggling to get the three bolts off of the EGR valve to see what kind of cleaning it will need (have soaked em with Liquid Wrench). Once that is accomplished, I will attempt to drain some of the coolant and then remove the BVSV and attempt to test it as well.

I guess my thought process is the rule out as many "cleanable" items as I can b4 reinstalling the carb after I clean it again.

Slightly related question - after pouring over countless posts in yotatech, I saw where someone was having similar issues and it ended up being their alternator (kind of the same line of thinking in relation to battery cables/electrical feed to motor/spark/insufficient current to run motor properly) Could this be considered a possibility or an extreme long shot? Thank you both for replying, it is much appreciated!!

old87yota

It could be the alternator, though I would think that you would have a hard time restarting the truck because the battery would be discharged with a bad alternator. Most of the time when alternators go bad on theses trucks, the brake and charge lights come on at the same time but it does not always happen. Check the voltage with a multimeter at the battery without starting the truck. It should be right around 12.6 volts. How old is the battery itself?

I would try to figure out the cause of the problem before replacing parts at random. That can get expensive!

Unless if the parts actually need replacing anyway.

How does the coolant and oil look? Any white smoke when the truck does run (not the steam that naturally occurs on a cold morning)?

Hopefully some more experienced people will chime in. All I am doing is making sure that you check everything that the engine needs to run properly.

Audrienne

Jake - true about restarting the truck - starting it is not at all a problem. I don't know the age of the battery, but it does not look particularly old. Husband has all volt/ohm meters on his truck, so my hands are tied as far as testing right now.

We changed the oil when we got it, was dirty, but no obvious metal bits/shavings/metallic shine on the paper towels b4 changing. Also checked oil after changing and still looks good and clean-ish.

Coolant is good, level-wise. Could probably use a changing, but not terribly cruddy.

Truck doesn't smoke (thankfully). No white, no gray, no black smoke.

When we changed the plugs in early Sept, we found that the PO was running platinum plugs in it (I am not a fan of plat plugs in older vehicles). We installed the recommended plugs (can't remember the name). When we took out the plat plugs, they were all clean - no weird deposits, no signs of oil, no signs of running too hot.

And yeah, I am not a fan of replacing parts at random....testing them, sure, but not buying whatever "seems" next on the list.

Thanks again for your input and please continue. All of our vehicles are older, so working on them seems perpetual, but at the same time, this is not something we do for a living and I am sure that we have missed something important to check!

Audrienne

UPDATE: Well, I finally finished cleaning out the carb again - but didn't find anything in it to indicate a problem or a clog or blocked passage, etc. I reassembled it, put it back on, said a quick prayer and started the truck. Of course, with no gas in the carb, it took a minute to get it started, but it did start right up. I kept my foot on the pedal, afraid it was gonna die, until I figured it was warmed enough that it should hold it's own idle. YAY! It is sitting outside right now, idling BEAUTIFULLY!

I did not clean the EGR Valve (couldn't get it off the truck) but I did clean up the filter a bit.

So, basically, I have no idea what I did to fix the problem...and I am not certain that it is fully resolved. I guess that time will tell and I will post here if I starts acting the same again. I will also keep an eye on this post if anyone would like to weigh in on other things that they think I need to address. Thank you all for your time!