[subzali]

I'm searching the archives right now, but thought I could get a post up since this is kindof urgent.

Driving home tonight. Truck has sat for about a week or two, ran fine a month ago when I was driving it everyday, and has run fine since even though it's been more or less sitting, but it's been started and run for a few minutes every weekend for the past couple of weeks. Fuel was basically empty.

Tonight I filled it up to about 3/4 and was driving up to Golden (~50 minutes). Running on the interstate at about 60-70 that whole time, running great, making great power, smooth, then I got onto I-70 West from I-25 north. I had gone through just under a 1/4 tank of the new gas (85 octance, which it has run for 2 years with no problem). There is a small hill there, and I immediately noticed a lack of power, but it wasn't just the hill, there was something not running right with the engine, it was immediately dogging down to 50 on just a slight incline. Once I got on the flat I couldn't get it to pull above 60mph and then it started hesitating like the brakes were sticking intermittently or something. Then on a corner the engine quit for a split second (my Lockright made the truck lurch pretty suddenly) and then starting running again, but getting rougher. So I was getting close to Wadsworth and it was running pretty rough with no power, so I shut the engine off and coasted to a stop. Tried to get it started again, didn't want to start so I waited for a minute and then it started again, but I have to keep it revved up to keep it running and it runs really rough. Made it to Treeroot's house, and made some diagnostics.

This is what I've checked - 10/76 FJ40 with stock engine etc.:
-No oil leaks anywhere (oil pressure is good)
-All vacuum hoses that had previously been hooked up are still hooked up (checked multiple times)
-All wiring at the carb (I think) that used to be there (though not complete I don't think, the truck ran fine with/without it) is/was still there, as far as I could tell. Don't know what most of it does or would do if it was hooked up...
-Dizzy looked fine on inside (electronic '78)
-Glass bowl showed good level of fuel in carb even while running (not starved before it reaches the carb)
-Primary barrel has plenty of fuel being squirted into it (not fine mist, kinda "droplety," but that shouldn't make the truck run rough should it?)
-Secondary barrel doesn't look like it's ever been used, but I don't think that has anything to do with this. That's a separate issue.
-When it would chug and die it would spit a little fuel back up the carb at me (had the aircleaner housing off) right as it died.
-Plug wires all tight. Pulled them one by one with the engine running, the only ones that made any difference to the way the engine ran (engine speed slowed down) were #3 and #4 (made engine drop in rpm). Unplugging 1,2,5 and 6 (one at a time) didn't change the way the engine ran at all. What?
-All plug wires arcing to plugs, so the plugs are getting voltage and should be firing.

Yeah so don't know what else to check. Thoughts on what might be wrong?
-Something jammed in a jet in the carb, or fuel not being misted causing problems.
-Bad fuel? Get some fuel additive and see if that helps?
-Reading some other threads, could my coil be puking out on me?
-Fuel cutoff solenoid?
-It happened pretty suddenly, but I couldn't find anything that changed. So either electrical or fuel related I think. But what changed?

This is my only vehicle until my red truck gets a new timing chain tensioner, so the sooner I can get this fixed the better.

[Pin_Head]

Bad fuel or fuel delivery (rust/junk in tank; plugged filter; pump) would be the first things that I would check.

[subzali]

Glass bowl has a good level in it even when running, so still check it? Maybe I got water in the gas or something? It was kinda sudden and it's been getting progressively worse...

[Phrog]

Might a plugged PCV valve cause this? Easy way to check -
remove the valve and see if it helps.

-Phrog

1972 FJ40 'Kermit'
1988 FJ62 'Zippy II'

[badass]

I had the exact problem you are having in my 79 2f. It would barley idle and if it did it would idle real rough unless i reved it. Turned out there was water in the gas and gas tank had some rust in it.

[petescoffee]

Clogged fuel filter. Put a new one in. I use aftermarket clear ones so I can see if it is clogged. You would be surprised how much crap it catches and I have new fuel tank, lines etc. Just in case you got some bad fuel get an additive that will disolve water.

Also check your wires on your ingintor and make sure one did not break off or is coming loose.
Just my $.02

[subzali]

-I noticed the PCV was very erratic...but I just recently cleaned it out and it was fine.
-Still need to check the fuel filter...but if I can see fuel in the glass then that should be fine right?
-I put HEET into the gas tank and have run if for about 20 minutes since then; it's been in the tank almost an hour now, no change.
-It was spitting fuel back up the carb last night when it was about ready to die, then today it actually backfired and I saw exhaust coming out of the carb once. I have the valve cover off to check the valve springs, but now I'm thinking it has to do with vacuum advance or something on the fully electronic dizzy? I don't know how to check timing or vacuum or anything, any tips?

[subzali]

Okay, valve on the firewall side of cylinder 5 has like 1/8" or 5/32" of play (engine is warm). Is that bad? Others are tight, a couple have a small amount of play. Even if this isn't related, I'm assuming it's bad?

[Pin_Head]

Originally Posted by subzali

-Still need to check the fuel filter...but if I can see fuel in the glass then that should be fine right?
- any tips?[/B][/Color]

If you are checking it when it is idling you may be getting fooled. At idle it doesn't consume much fuel, so you need to check when you are having the symptims by cutting off the engine and coasting to a stop. If it is acting up at idle when the truck is stopped, it is more likely to be dirt in the fuel bowl.

The bucking and spitting back through the carb are classic fuel starvation symptoms.

[Hobbs]

If it were mine, I would perform fuel pressure and volume tests. This would be a good oportunity to look for water in the fuel. If it is getting sufficient fuel to the carb, I'd pull the top off the carb and have a look.

[gladly]

change the fuel filter
really, before you check everything else, just put in a new filter.

[subzali]

So I took the valve cover off since it started backfiring, thought maybe a valve spring is causing problems...and this is what I found:

The other side, see how that third from the back (intake on #5) can almost slip out of the top of the pushrod? :

This isn't at TDC, but that still seems like way too much gap. At the position shown in picture 1 (pushrod is not pushing on lifter and can be spun) the distance from the top of the spring cap to the head casting is about .160 less on these two valves (intake on #5 and #6) than on all the other valves. Could something be stuck in the valves, keeping them open?

Oh yeah, I'm continuing with your guys' list of things to do, fuel filter etc...

[subzali]

Check this out. Plugs 1, 5, and 6 (attached) have been impacted. Plugs 3 and 4 were a brown-red-burnt orange color, and 2 was that color but more nasty. Looks like I'm parking the 40 for a while.

Plug 1:

Plug 5:

Plug 6:

[Pin_Head]

What ever it is, it can't be good.

So what did your engine suck in?

[Hobbs]

Ouch! Hurts just looking at it....

[subzali]

I didn't notice anything being sucked in...what's the best way to dismantle and see? Should I start with the manifolds and see if I can peer in? Then the head will probably have to come off - do I have to disassemble the rockers/valve springs etc. to get the head off?

BTW does anybody know what a burnt orange/reddish/brown deposit on sparkplugs means?

[scouthead]

Those spark plugs are depressing. Any metal in your oil? If not I would crank the motor until each piston comes up, and look in the spark plug hole with a flashlight. IF you can't find anyhting major/obviously wrong, throw some new plugs in (and a new fuel filter) and check the the compression. No sense taking things apart until you are sure you have to.

[Pin_Head]

I have seen that kind of carnage in a single cylinder when a valve head breaks off or a screw falls into the intake, but I am scratching my head trying to figure out how it would happen on 3 different cylinders, two of which are on opposite ends of the engine. You could try peeking in the spark plug hole and checking the compression, but if the compression is bad, the head will need to come off to fully understand what happened. I would guess that some of the valves are also bent, which would explain the excessive clearance.

[grant5127]

Jumped time... cam gear spun-out....

[Hobbs]

Pull all of your sparkplugs and spin the motor by hand. Look into each cylinder as it comes up to TDC. Look for piston damage and foreign objects. Kinda looks like the head will have to come off..... I hope I'm wrong.