TheTinSoldier

Hey all,

I'm new to toyota forums, but it seems like there are some really helpful and passionate people around here. It's nice to know there are people who love their trucks and their brand and wanna help people out. Very cool.

Got a problem with my '88 pickup 22r 4x2 4Spd short bed ~100,000 miles. Unfortunately no tach, so I can't give specific rpms.

This problem had a sudden onset. Truck was operating fine until one day while highway driving I noticed irregularity when I let my foot off the peddle (clutch engaged) to slowly decelerate at higher speed (~65mph). Eventally I hit traffic, had to disengage the clutch and take my foot off the gas to brake, at which point the engine died. I restarted, it couldn't hold idle, died. I restarted again and negotiated the peddles to keep the rpm up, brake, and use the clutch at the same time to get to my destination.

It seems to operate fine with the gas peddle depressed (i.e. mid to high rpm).

Later in the day I started the pickup (no particular difficulty there) and drove it maybe a mile to another parking lot by the same method. When I got there it died (puttering out very violently). I went away to take care of something and came back after ~15 min. I started it again and it would waver between almost puttering out (I mean just BARELY not) and pretty high rpm while fast idling (I hadn't tapped the pedal yet). Anyway, got it home at the end of the day.

You can see some of the general behavior in the video I'm posting below, although it doesn't show how it sometimes oscillates between very nearly dying and revving itself up. In the video it just dies. Obviously it also doesn't show how it's rocky when letting off the accelerator in any gear clutched engaged (i.e. while driving) at high rpm. In the video I also cover the port, manipulate the plate, manipulate the gas peddle (any time you see the driver side plate move), show how it dies a few ways, and talk about what goes on.

It has no stability at lower rpm. It doesn't just seem to be simply idling too low... it appears to be unstable and unable to maintain in the idling range of rpm... it can't even get to idle rpm without dying or sputtering really low and bouncing way up in rpm.

You may also notice in the video that when I cold start and it fast idles, the rpm creeps upward and gets significantly higher than it's normal fast idle rpm. You'll hear me faintly say "it's idling a little high" in the video...I mean to say it's fast-idling high.

I tested the fuel cut solenoid/anti-diesel solenoid, and I get the click, so it would seem that's working, unless the magnet is working but the plunger is somehow stuck. I'm not necessarily convinced that would be the source of this problem anyway.

Any ideas? I've done quite a bit of searching, and while I've read of similar behavior, I haven't heard of it quite like this, or seen a fitting resolution. Everyone says check that solenoid, so I did, but not sure where to go from here.

Don't know if it's relavent, but it's been somewhat cold here ~30degF.

Thanks a lot guys. I really appreciate you taking the time to help me out.


VIDEO OF PROB: http://www.youtube.com/watch?v=aS7nPZpybVk

TheTinSoldier

...or is it even possible that maybe this isn't a carb issue???

abecedarian

Check the fuel level in the sight glass on the carb fuel bowl- the fuel should be 1/2 way up the glass, give or take a hair. If there's no fuel visible, or it's full, the float may be sticking.

TheTinSoldier

Just read your post abecedarian, so I haven't checked that yet, but thanks.

Ok... so started it up today and ran it for while until it warmed up a bit. I was just letting it fast idle the whole time, although it would slow down and die a few times. Not even sure it's always the choke, but something happens to slow the idle and eventually kill it after fast idling for awhile. In the first video I'm posting below you can see how it's fast idling and then dies, but it doesn't appear that the choke is opening itself. I wasn't touching anything while this was filming.

Eventually I got it to get into the oscillating idle I was talking about in my original post. You can see this in the second video I'm including below. Again, I'm not operating the throttle, as you can see by no parts moving on the carb. You can also hear in both the first and second videos that the fast idle is too high.

Anyway, at someone's suggestion, I tried experimenting with the Auxillary Acceleration Pump. I turned off the engine, removed the Auxillary Acceleration Pump vacuum tube and then reconnected it (to make it easier to take off while the thing was running). I started it up and as usual it started its fast idle (the same "too fast" fast idle that I've also been experiencing with this). I pulled off the AAP vac tube and the rpms shot way up, so I reconnected it and turned off the engine.

I noticed no fuel leaking from the AAP vac tube nozzle either time I disconnected it.

I grabbed a screwdriver disconnected the vac hose again and plugged it with the driver, still leaving the nozzle on the AAP open.

Started up and it went into a somewhat unstable fluttery idle for awhile, as you can see in the third video. The choke was partially closed during this idling, and when it automatically opened all the way up, it died, which again, you can see in the video.

Then I started it back up without changing anything, and voila!...the thing idled normally(video four)... fixed!!... at least, so it seems??

[I'm referring to the AAP when I say "whatever the hell that thing's called"... sorry... still earning the part names]

I ran it, throttled, restarted, and it seems to function and idle fine.

More weirdness; I plugged the AAP vac tube back in to try to replicate my original problem, and no dice...it's running fine. Putting everything back just the way it was doesn't bring the problem back.

So, I'm happy, but I'm a bit bewildered and a little dissatisfied.

Anyone got any ideas? Do you think maybe the diaphram inside the AAP was stuck or something and unplugging and running the engine did something to "unstick" it?

Think it's fixed?



I'm letting it cool back down right now, and I'm gonna go back out and try to see how it starts/runs and take it out for some errands. I'll let you know how it goes.



VIDEO 1:

http://www.youtube.com/watch?v=jGEZO4tHMww


VIDEO 2:

http://www.youtube.com/watch?v=opaMfIB5-GI


VIDEO 3:

http://www.youtube.com/watch?v=uyQFK9iYnB0


VIDEO 4:

http://www.youtube.com/watch?v=K4DA_fjWW-c

yoterr

kinda sounds like a bad vac leak, check all your vac line connections n such n your brake booster line, if nothing try some carb cleaner n spray it AROUND the carb n try to hear if it idles up,

TheTinSoldier

been driving it a few days, and no probs

tried spraying carb cleaner around and no effect

still puzzled

it seems kinda like it might have a bit more sluggish pickup, though... seems a tad weaker at high rpms than it used to be