LUVTruck.com

I got to thinking about my earlier post, and what I know about carbs, and realized the truck is not running too rich. It's running too lean. The backfiring through the carb is the opposite problem of a stuck float, which causes it to run way rich and dump fuel out the tailpipe. After a quick review in the manual, the FLOAT level needs to be set mid-sight glass. My initial understanding was that the FUEL level needed to be mid sight glass, and so I've adjusted it too lean.

I'm going to use a silver sharpie on the float, so I can see the mid point through the sight glass. I don't have a fine enough measuring tool to set it by the book. I may try to use feeler gauges and the other carb body I've got and adjust it that way. It's always been easier for me to adjust the float if I can turn the carb upside down.

Just finished up about 54 hours of work in 4 days, so I'm going to crash for a bit. I'll post more later ...zzzzzzz....

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

Won't go above 50, and backfiring on acceleration? Two things come to mind. Late ignition timing, or starving for fuel (too lean). When you set timing make sure it is idling at 900 rpm or slower or the advance in the distributor will throw it off. Also maybe the secondary barrel in the carb is not opening up and limiting the power. It should open at about 3/4 throttle. If fuel related change the fuel filters as others have said. Don't forget the one inside the fuel pump-if you have the stock pump.

Its nothing to do with compressing the fluid.

If its at the motor it has to suck it. A mechanical pump is better designed to do this with a large digafram and a long action.
An electric pump is more efficent at pushing fuel. Smaller digafram with a more repetative action. They dont like to draw over a long distance.

Pump works OK, it moves plenty of fuel. Well it did on the van i got it out of mounted 6" away from the tank.
Its a different story now that its 6" away from tha carby.

Yeah fuel filter change might be a good idea. Will do that one day and move the pump to down next to the tank. Might just put a motor back in it that the mechanical pump can go back on. The 4ZB1 motor has no hole in the head for the pushrod so you cant use the 4ZD1 mechanical fuel pump.



Them Koala's aint bears. They are Koala's, thats it. Not from the bear family.

Im not goin anywhere near one. They are nasty suckers. Got big long claws for climbin trees. They are tempramental, they get that from living on a toxic diet of eucalypts leaves and are basically stoned all the time and sleep a lot. Hence why they get grumpy and are prone to be nasty.


Cheers, Bob.

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Current project, 1979 KB Isuzu Ute.

Daily driver, '86 Rodeo Spacecab.
Chasing parts for Isuzu Impulse.

Coinkadink, mine started doing about the same thing today, after a little "hot rodding" around last night. Started checking all the usual suspects, looked inside my distributer cap and arcs and burn marks all around it and the rotor was kinda scorched looking. Picked up a set at Autozone and replaced both, purring again. No more gunning it for me...well, maybe

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FIAA: Color Guard

I've got a dead cylinder.

#3.

Not sure why I didn't figure this out sooner.

I'm going to put this truck up for a bit, and start cruising CL for an A to B work car. Maybe throw a can of liquid head gasket in the '78.

Dunno' really, but I'm burnt on this for awhile.

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

I sure am glad you knew better than to mess with them koalas. I'd hate to hear you were down under typing wid your feet on account of having lost your hands to a kranky koala.

Egg, you can tell me where to access the filter on the pump right? I can't say for sure I've got the stock pump, but pretty much everything on this truck was original before I got it. I think I've got bad gas, but it's still running okay, just not as quick. 79, I'll take a look at my cap and see if it's got anything wrong, but it's like the best cap you can get, with brass contacts. I have another one with aluminum, ready as a spare.

Nuker man, what's dead? Is it the wire? The cap? The plug? Can't be the valves, can it? I hope you find out. I know those burns hurt.

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'78 1.8L 4-speed Fleetside

The only thing more beautiful than a sunset is a sunrise.

Theres also a mesh/gause filter ring in the banjo fitting on the carb right above the needle and seat. You need to hold the nut underneath to get the nut ontop undone.


Bob.

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Current project, 1979 KB Isuzu Ute.

Daily driver, '86 Rodeo Spacecab.
Chasing parts for Isuzu Impulse.

Nukeday, step back, take a deep breath, resist the urge to hit or kick something, ( the doctor bill you save can go on parts ) and give it a day. Working on stuff can be frustrating. It may turn out to be something simple like a bad wire or plug. I hope so. Don't give up, it's a nice looking truck and when you get it right it will be worth it.

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If you think no one cares, try missing a couple of payments...



FIAA!

SFPP!

Thanks mytmouz. I'll get this solved one way or another, but you are right, I'm frustrated.

When I changed the valve cover gasket, I didn't adjust the valves. At the time, I thought the miss was something a bit more minor than a leaky cylinder.

I'm wondering what, if any, relationship the valves have to this oily cylinder? My understanding is that if it's not blowing smoke out the tail pipe, and the plug is oil fouled, it's a cinch that the rings are shot. If the plug was firing at all, it should smoke. No smoke, no compression, right? I can adjust the valves, but I'm not sure the effort will provide any measurable results. I really should do a compression/leak down check, I guess...

I don't have much $ to put into this truck right now, and I'm waiting to hear back from luvprojects on an engine he's selling. I might just have to low buck it for now and go with a 'gasket overhaul'. This would be much easier if I can get my hands on a long block to prep, and then just swap them out when it's ready. I've got the '78 here, but I'd rather not pull two engines if I don't have to...

Suggestions?

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

Okie, so here is the diagnosis -

'78 - Rotten freeze plug on the back of the head. NOT the head gasket. Yay? I think it's a 40mm, that's a big 'un...40 millimeter = 1.574 803 15 inch. This one is available at Napa and expands 1 1/2" to 1 5/8", should fit, right?



'79 - Dead #3 cylinder. Non-fouler provided absolutely no relief, still kicking back up through the carb.

I'm working on either a complete engine or a just a head. Or maybe if I'm feeling like a lunatic, both. Swapping the head is less work, but that means I drive the '78. I'll see if I can't patch it for a while with the expansion plug...

I need to get this done ASAP, I need a (just one..hahaha) vehicle to get to work.

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

How bad is the freeze plug????

Leave the radiator cap off, no cap means no pressure = no leak.

A big dob of silastic and a self tapping screw has got me by before.



What you could do is pull the freeze plug motor out, do all the plugs with brass ones and put it in the truck with the dud cyl. Then sort out the dud motor or get another and put that in the freeze plug truck.



How long does a new spark plug last in the motor???

I cant remember if its cyl 3 or 4 in my ute, it takes about 6 months to clag up.
If its more than a week, carry some plugs and a spanner with you.
Im not sure if a hotter or colder plug would help it spark better, make that oil burn. lol.


You say no smoke, have you followed someone driving your truck??? You wont tell from the drivers seat if its smoking a bit. Needs to be real bad before you will see it.
I thought my ute didnt smoke, it does a bit high in the rev range (when it starts to rattle) found that out by following someone driving it.



You could try fitting new valve stem seals and giving the valves an adjustment.
You can fit the stem seals on the truck. Just need to be a little creative and have a compressor.

If you make up a jig to air fill the cyl before you even go a step further you could do a leak down test, that will tell you 100% if you got shot rings or a burnt valve or a blown headgasket.
All you need is an old spark plug. Bust the ceramic off it, you want the threaded bit at the end. (or get a bolt that thread and drill a hole down the middle.) Weld/braze a fitting to the threadded part. You need a tyre air guage and via a bit of tube or hose connect that to the fitting youve made. Now you can blow and hold air in the cyl.


I take it youve done a compression test with a hand held tester??? Cant recall reading about it. Could be a burn head gasket between two cyls. Strange about the plug if its this.


Cheers, Bob.

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Current project, 1979 KB Isuzu Ute.

Daily driver, '86 Rodeo Spacecab.
Chasing parts for Isuzu Impulse.

Of course, it would make a big difference if the valves are adjusted to the proper clearance.

With the engine cold, pull out the plugs, and turn the front crankshaft pulley nut clockwise with a 24mm ½"-drive rachet. Stop when #1 piston is on compression stroke. Verify that the ignition rotor is in the #1 spot and the timing mark is at 0°. At this point, the #1 cylinder's intake and exhaust valve clearances can be adjusted. The intake valve clearance should be .006", and the exhaust valve clearance should be .010". #2's intake, and #3's exhaust are also adjustable now. When those four valve clearances have been set, turn the crank 360° and do the others; #4 both intake and exhaust, #2 exhaust, and #3 intake. Put it all back together and notice the improvement.

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'78 1.8L 4-speed Fleetside

The only thing more beautiful than a sunset is a sunrise.

I tried that ^^^^^^^^^

Made no difference at all. lol. Guess its not the way to fix excessive piston slap.


Worth doing all the same.


You dont need to look at the distributor, use the timing marks on the crank pulley.
With the valve cover off when cyl No 1 is on compression, cyl No 4 will be on rock/overlap (exhaust closing and inlet opening). The rockers on No 4 will be tight. On No 1 they will be loose and should have clearance unless you have a tight valve.

Bob.

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Current project, 1979 KB Isuzu Ute.

Daily driver, '86 Rodeo Spacecab.
Chasing parts for Isuzu Impulse.

I thought it sounded like Nukeday hadn't done it at all. I did it the other day, and it made a lot of difference. The engine ran smoother, and was a lot quieter. Of course that was the same time I changed the plugs (per your advice Bob), and also changed the coil. I think it's easy to make a mistake on the valve adjustment if you don't follow the correct procedure. The result could be disaster, gouged pistons, and bent valve stems.

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'78 1.8L 4-speed Fleetside

The only thing more beautiful than a sunset is a sunrise.

You would have to get extreemly out of shape to break something.

Bob.

_________________
Current project, 1979 KB Isuzu Ute.

Daily driver, '86 Rodeo Spacecab.
Chasing parts for Isuzu Impulse.

Let me ask you Bob, how do you feel about a camshaft losing the locator pin into the sprocket, and the engine stopping, then pushing the pin back into the camshaft and continuing? Do you think the engine would suffer much, i.e. the valves and pistons?

Maybe Nukeday's engine is out of shape, I haven't seen it. The stories are haunting though.

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'78 1.8L 4-speed Fleetside

The only thing more beautiful than a sunset is a sunrise.

The freeze plug is done, it's rotten from the center out. I picked up a couple of expansion plugs this morning, but I'm going to get some sleep before I get started. Yay, mid shift.

I adjusted the valves, no difference really. A bit more clatter actually, but no improvement in driveability. The plugs last about 5 minutes in cylinder #3, and are so oil fouled I can barely use them in another cylinder.

I'm changing tack, and am going to concentrate on the '78 for now. It needs front end work, but not as badly as the 4x4. I'll put the electronic dizzy back in it when I'm sure it's not leaking coolant. I may put the weber on too, when it arrives.

More later. Thanks guys

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison

Hang in there nukeday!

Look at it this way...at least you aren't bored in your spare time, or out roaming around in the streets of your town getting into trouble....lol

Sounds to me like you really need a compression check on that dead cylinder. If it is good or similar to the other cylinders then it isn't rings and your oil issue is from the valve stem. Sorry to say tho, but my gut says you've got a broken ring or something.

Another trick I've used on changing stem seals is putting a length of soft rope into the cylinder through the spark plug hole. I used about 4ft of cotten rope with a big knot on the end. Then turn the motor over by hand until it compresses the rope into the head and valves. Remove the springs, replace the stem seals, put the springs back on, and the valves never move. I actually had to bang on the spring keepers to get them off the stem the last time I did this, and air would not have kept the valve from pinging into the piston.

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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good

It didn't come peacefully, but I got that not-so-rotten freeze plug out of the back of the head, and I only bled a little. I ended up pushing an allen wrench through the hole that was in it, and then leveraging that to get the hole large enough to get a brake adjusting tool down in there. When the hole was big enough, I put one leg of an open end crows foot in the hole. Then with a 12" extension, and my jack handle on the end of my little 3/8" breaker bar, it eventually popped out. I worked my way up my whole set of crows feet as I tore the hole in the plug, until it finally came out with the 3/4". Good thing, anything larger wouldn't have fit between the firewall.

Of the two expansion plugs I picked up. The 38mm unit slid right in the spot for the old freeze plug, and the 41 mm didn't. But guess what? Without any way to keep that 38mm bugger from spinning while tightening it, I just went and got the crowbar and put the bigger one in. I'd have liked to have seated it another 1/4", but I ran out of time. I'm not 100% sure it's going to hold, but it's not leaking now. The rad cap is rated for 16lbs (?) so it doesn't have to hold any more pressure than that, right?

I'm going to try to pick up an engine for the '79 (from luvprojects) this upcoming week, now that I have the '78 up enough to go get it.

Thanks 800xl for visiting my mess of a thread. I was looking over ctmandu's post about blow by, and my '79 makes A LOT of blow by. Is it possible it's just the valve seals? I've always used clothesline cord too, for stuffing in the spark plug hole...

Compression check is pretty straighforward, but can someone remind me on how to do a leakdown?

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"If we did the things we are capable of, we would astound ourselves" - Thomas Edison