dfgilbert

1988 Toyota Pickup 2WD 22R 5speed Manual

So, when I start my truck up, it idles like someone is jumping in the bed of it. It often blows black smoke and soot out the tail pipe in puffs (ie, it's not constant or continuous).

If I try to drive it in this state, it will "jump." What it feels like is a huge hiccup where it leaps forward then feels like it's going to die.

Warming it up does not necessarily get it out of this state.

It doesn't happen all the time.

In the mornings, it is less likely to happen than in the evenings after it's been driven a while. This might just be coincidence, but that's my experience with it.

Here's an example, I drive to work, everything is fine. I leave work and head to the jujitsu studio, everything is fine. After jujitsu, I go out to my truck and it starts acting like it's going to turn inside out and explode.

The only way to get it to stop doing this is to really get on the gas. Like, if I rev the engine, it will stop and eventually quit doing it.

My father seems to think there might be crap in the fuel lines or tank that is clogging something up.

He also speculated that the timing might be off a little. I read similar threads that say the same thing, but they don't describe the problem as close to mine as I'd be comfortable with just saying that that's the case.

The guys who did a tuneup on my truck at Sears noticed it too and said it might be a misfire or the carburetor needs to be adjusted, but they were closing and couldn't help me with it.

It is not leaking oil, I've been checking that daily. There's also no water in the oil.

Anyone have any experience with this?

If it's something I can do myself, I'd rather not pay a few hundred dollars for someone else to do it. I'd appreciate any insight.

combatcarl

Well...Sears and tune up in the same sentence is alarming...but start with a decent book, or factory service manual and set your carb up right. Then see of there's any vacuum leaks, you could try replacement fuel filter, beyond that, I don't know too much. Sounds like an old Ford I had that the choke would always stick on..

dfgilbert

Sears is a bad place to take my vehicle?

All this stuff to check is in the service manual? I'm gonna order one on Amazon.

Thanks for the tip.

combatcarl

Well, I won't say Sears is bad, but unless there's a dedicated Toyota nut working there, I'd personally pass. But I'm weird about other people touching my truck. Unless I'm watching, I like to watch..heh. You can search "Toyota FSM " here, there's PDF formats to look at and print off what you need, I have it on thumb drive, easy to setup laptop, flip through under the hood.

slow-mo

This is typical of a rich fuel setting in the carburetor.



How long between the time you turn off the engine and you start the truck again?

Where is the coolant temperature needle at?



That is possible.

When it happens again look at the fuel in the carburetor float bowl window. Where does the fuel sit in the window? The fuel is supposed to be in the middle of the window.

A simple maintenance procedure would be to replace the fuel filter. Unless you know when you have down it before. This would not be "throwing parts at it" until something works as the filter is a critical component to fuel flow & does get clogged if it is malfunctioning.

abecedarian

Sticking choke or kickdown cam?
Bad heater in the choke pull-off coil?

Leaking accelerator pump?

scope103

It sounds a lot like a misfire; fuel goes into the cylinder, it doesn't fire when it's supposed to, the truck bucks on that missing power stroke, and the unburnt fuel shows up as black smoke.

First, get yourself a timing light. http://www.harborfreight.com/xenon-t...ight-3343.html A cheap one is fine (as long as it says "xenon," I don't think anyone makes a neon timing light anymore). Start by checking the timing (it never hurts). Then put the pickup on each spark plug wire; when the plug fires it will flash the light (only plug #1 is synchronized with the mark you use to set the timing). If one of the wires doesn't produce a flash, that plug is not firing.

You can also visually inspect the plugs. Old-timers were really good at this, but generally you want all the plugs to look the same. If one is sooty or slightly damp with gasoline, that one's a problem. (Hell, once you've got them all out, replace them and make sure they're gapped correctly.)

dfgilbert

Guys, thanks for all the insight. Sorry for the delay, I was working up the nerve to actually stick my head under there and possibly screw things up worse.

I can't be sure exactly what the problem was, but it was causing a misfire. It was something in the distributor/cables/plugs assembly.

First, I downloaded the FSM that I found on here thanks to a post in this thread and read the trouble shooting.

Then I went out and adjusted the idle to see if moving it would cause it to stop acting up, it didn't.

Then I went and bought a timing light and checked to make sure all cables were firing, they appeared to be. Each cable was causing the light to flash.

Then, I checked to make sure the timing was correct, it was.

So, I went back to the auto parts store to buy a gapping tool and to sears to get the socket to pull my spark plugs out, 13/16 socket (off the top of my head).

While I was at the auto parts store I just decided while I'm under there, I'm gonna replace the cables and distributor cap and rotor. GOOD THING.

When I got home, I took the plugs out and they were all gapped correctly.

Here's what's weird.

So I went to pull cables and take the distributor cap off. Well, while I was pulling the cables off the cap, the cable to the 2nd plug from the front on the block was corroded all the way through. In fact, when I gently tugged on it it just crumbled apart.

The rotor was in good condition so I left it in.

I put the new cap on, connected the new cables to the plugs and cap.

Went back, fired up the engine, no more black smoke. No more violent idling.

So, it was definitely a miss-fire/cylinder not firing at all.

Everything is good. Thank you so much for your help. I had found the service manual on here and it was a huge help for trouble shooting.

rworegon

Nice work. And, you have the satisfaction of fixing your rig yourself.

slow-mo

Good on you for doing your own wrenching.

combatcarl

Yay! Happy endings are the best! But good, I was wrong. The real fix was cheaper and easier. Also, arming yourself with the manual helps out, too!