Smoke on startup and poor idle

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

S

sandcrawler

Joined
Oct 12, 2005
Threads
33
Messages
258
Ok here's the scoop. I have a 88 FJ 62, 142K, that i bought last Oct. Since then I have done a full tune-up (wires, plugs, rotor, cap, air/fuel filter), valve adjustment, fuel pressure regualtor, new thermostat, waterhouse top, new PCV valve, various misc hoses, one of the O2 sensors.

So here's the problem: when i start the cruiser up after it's sat for about an hour or so (a "warm" start) there's a distinct puff of blueish smoke, and it won't idle unless i give it a good amount of gas. If it's cold or hot, it fires right up, and idles perfectly at 650 rpm.

What could be causing this? Has anyone else run into this? What should I look at now?

Give me your thoughts guys.
 
Blue smoke means your burning oil somehow.
 
But it only happens on start up, other wise there is no smoke from the tail pipe. Would worn rings account for both the smoke and the poor start up?
 
Could be bad valve seals. Does it smoke if it's a cold start?
 
You know, come to think of it, it does, only less so. And on a hot start it doesn't smoke at all.

So assuming i have bad valve seals, what sort of fix are we talking about?
 
Sounds like valve seals. You will need to do a wet and dry compression test to isolate valve guides/seals from rings.
 
Ok, forgive my ignorance on this question, but what is the difference between a wet and dry compression test? I never did a compression test on the Rig when i bought it, but I have my suspicions about the #3 cylinder.

If it is bad valves seals, how tough of repair is that?
 
How do you know if your compression on cylinder #3 is bad if you have never done a compression test?

Bad repair. I believe that you have to remove the head, but you might be able to slide new seals down on top of the valves. I'm not sure.
 
LOL well, when i got the Rig, it had a terrible misfire - and when I removed the plugs the #3 looked terrible - it was all black and scored... while the others we're decent. I don't know that the #3 is bad, but it wouldn't surprise me also.

Hmm that doesn't sound like fun.

Ok let me ask this question. Since the rig runs pretty well otherwise - pretty smooth, decent fuel economy, etc, is this something I NEED to worry about? or is it something I can live with until I decide to do a rebuild?
 
sandcrawler said:
Ok, forgive my ignorance on this question, but what is the difference between a wet and dry compression test? I never did a compression test on the Rig when i bought it, but I have my suspicions about the #3 cylinder.

If it is bad valves seals, how tough of repair is that?
Click to expand...

For the dry test, you pull plugs, open carb throttle butterfly, and test each cylinder. For wet test, you do test again, but put a squirt of oil in each cylinder. The oil temporarily seals up the rings, so if the compression on a cylinder is low on dry test but comes up on wet, it is likely the rings, but if is stays low, it is likely valve not sealing.

I have not done seals on a 2F. You should be able to do it leaviing the head on, but will need to keep valves up on the affected cylinder then you remove the valve spring. (You will also need a valve spring compressor) I took a spark plug pounded out center and welded on a quick connect, so I could air up the cylinder. So it is a little bit involved.
Best of luck.
 
Derrick Willis said:
You should be able to do it leaviing the head on, but will need to keep valves up on the affected cylinder then you remove the valve spring.
Click to expand...
There is a tool available at AP stores that will do this.
 
Ok now I see the difference between the dry and wet test. Since this is an on going problem for me, i'll look into doing both compression tests in the next few weeks.

Thanks for the brief write up on doing the seals; also thanks tip on the tool. I'm going to look at the FSM this weekend.
 
The Haynes manual has a procedure for replacing the valve seals with the head still on. I am contemplating doing it this spring as I have the same start-up smoke(but no idle trouble).

Mike
 
It sounds like valve seals. If you choose to replace them with the head on you should use the rope trick, not compressed air. If you seach rope trick you should find some info. If not PM me and I will try to help you out with an explanation.

Dynosoar
 
Well from a thread I just read about doing the vlave seals on a 2F, this seems reasonably doable.

Should I just use OEM toyota parts for this? Is there any compelling reason to pull the head? I'm afraid that if i do that I'll want to do a bunch of other stuff.
 
ben1be said:
The Haynes manual has a procedure for replacing the valve seals with the head still on. I am contemplating doing it this spring as I have the same start-up smoke(but no idle trouble).

Mike
Click to expand...

The idle trouble happens only when the during the initial start-up, and only when it's warm. If it's cold or hot, it starts up perfectly, and idles like a champ. Is there something else that could be causing this?
 
if you are going to go through all of the trouble to replace the valve seals, just go ahead, remove the cyl head and have it rebuilt. you can get a gasket set that has all of the seals and gaskets you need. a good machine shop will hot tank, media blast, regrind the valve seats and deck plane the head for you. all together, the gasket set should cost about 50-60 buck and the machine work not more than 200.
 
That's a good suggestion; it would also give me a chance to get the intake manifold cleaned out too (and maybe install the MAF headers and exhaust!)

Then I'll be ready to swap in the 2F block... :)
 
You must log in or register to reply here.

Share this page

Back
Top Bottom