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OT - CAT 3208 Diesel problems

Jager

Hot Rolled
Joined
Jun 20, 2008
Location
Yukon, OK
Sorry for the off topic post but I have a CAT 3208 that I need to get running asap and was hoping someone here had some experience with them. It is in a early 90's Ford F-8000 bucket truck.

If I give it a shot of starting fluid, it will fire up for a few seconds then quit. Recently we have been able to get it started after 7 or 8 shots of starting fluid. Now it will not start.. I tried about 15 times today and drained the batteries again. Air filter is clear and there is fuel in the tank.. It is also about 90+ degrees out today.

I dont have any experience with CAT's.. so any help is appreciated :)

Andrew
 
Forgot to mention... The last time it was running, the idle was hunting upo and down several hundred rpm. It ran fine, just hunted up and down.
 
Perhaps you broke something with all that ether. Been there, done that, on a Detroit 4-53 -- piston broke. Do you get white smoke or mist from the exhaust while cranking? That will tell you that at least fuel is coming out the injectors. You've probably got either no fuel or insufficient compression, or both.
 
I have only been giving it a quick shot of fluid.. not enough to pool in the intake.. so hopefully that is not a problem. It sounds fine while cranking. There is some white smoke when it fires up.. Not sure if this is unburned fuel or just the starting fluid burning off.

I have a feeling it is injection pump related.. but not sure how to go about diagnosing it. I am slightly familiar with Cummins and Detroit Diesels, but never worked on a CAT.

Thanks
 
The 1st thing to check is fuel filters and if they have not been changed in awhile might as well get it done.

You might also be having a drainback problem on your lift pump or intermediate pump. On a 3208 IIRC its on the drivers side of the engine. You will notice there is a little round knob on it that you can unscrew until you can pull the knob up about 1 1/2 inches or so. That is a priming pump. Next time you go to start it, pump the thing up till you are sure you have fuel pressure to the injector pump and then give it a try at starting. Make sure you push the pump back down and screw it down snug, seems I have had problems with that in the past too. If that makes the truck start better, chances are the check valve in the lift pump is bad or its just wore out. That might also be the cause of your hunting.

Of course there are other things that can give you problems, such as a rusted fuel line, collapsed fuel line hose, injector pump going bad, skipped timing, and/or pump timing has been fiddled with, etc. If the truck has run and does run decent once it has been started I am thinking my first check would be the lift pump.

CAT engines are pretty decent when they are newer or have been well taken care of but once they get to that stage of life when they are needing constant attention they can be a pain. They are also expensive to work on. I pretty much like for my diesels to be Cummins, IH/Navistar, or Deere.

tim
 
I should of mentioned if you do find you can easily pump fuel up to the injector pump it is almost inevitable you will have to purge the air out of the injector lines to get the injectors to function.

Let us know what you find.

tim
 
Like the last post the beast has a priming pump. If you lose prime in the fuel system it takes a while to clear the air out. Sometimes you need to crack(vent) each injector.

 
Thanks for the help guys. I will work on it again this evening once the batteries are charged again.

Andrew
 
Hi,

Been a bit since I worked on a 3208, but sounds liked it may have skipped timing. Seen it happen. Bring to top dead center, and pin the injection pump. If memory serves, the hole is on the top of the pump under a plug. I believe that it is 1/4, or maybe 5/16. Drill bit works fine. Next, check crank location. Again, if memory serves, there is a pipe plug on the bellhousing that you can pull, and thread a 3/8 NC bolt into the flywheel through. If you can thread this bolt in, timing is good. If not, I believe that the pump gear is on a taper, which may have slipped. If this is the case, and provided it hasn't torn up the tapers, it can be re-set by pinning the crank at TDC on the compression stroke, pinning the pump, and tightening the gear back on the taper. Hope this helps. Don't see too many 3208s around anymore.

John
 
I Googled "CAT 3208 Diesel" out of curiosity and found several forums.

If your problem is not solved here, that might help.

Paul
 
If you aren't getting white smoke when you crank it,, you ain't gettin fuel. As mentioned above, you need to go thru the bleeding process. I wouldn't even think about mechanical problems, out of time, etc. until you bleed the fuel system. The next problem you have is its 3208 Cat, lousy engines, expensive on parts, etc. If you don't get it running easy, I would just forget it and get a better truck or motor, like a I-H DT-466, 8.3 Cummins etc. In my experience the inline 6's were the best diesels.
 
If you aren't getting white smoke when you crank it,, you ain't gettin fuel. As mentioned above, you need to go thru the bleeding process. I wouldn't even think about mechanical problems, out of time, etc. until you bleed the fuel system. The next problem you have is its 3208 Cat, lousy engines, expensive on parts, etc. If you don't get it running easy, I would just forget it and get a better truck or motor, like a I-H DT-466, 8.3 Cummins etc. In my experience the inline 6's were the best diesels.

But I know a lota boats with singles and twin engine sportfish boats with turbo chargers on the 3208 pushing the HP rating up to 375 or 430 or so... and they dont have the problems.

Another friend has a 53 ft with twin C 13 525Hp Cats... they just purr along pushing him out to the fishing grounds off North Carolina and New Jersey.

This is from the Cat spec sheet..
Durability
Laboratory tests and engine disassembly analyses indicate Cat® C13 engines are expected to have a B50 life of one million miles with Cat's recommended maintenance.
So how long does it take to run that far? Why so critical of Cat?
 
Remember the key has to be on while you bleed it or you're pumping for nothing. There is a small t-handle valve on top of the pump you can open to pump up through the filters, then close it when you get fuel out the drain tube and crack open all 8 fuel line nuts where they go into the heads. When you get a decent flow close them off and try to start. That is as close to the nozzles as you can bleed it.

The hunting is definitely not right, maybe a bad buffer spring in the pump. Bad governor shaft seals are a possible place to suck air if it's nothing in plain sight. 3208 should never need starting fluid.

Another thought, does it have one of those phony Cat/JD type clear water separators just before and below the hand pump? 3 tubes in back that push through o-rings in the base, tin retainer, they're junk, famous for losing prime, if you do rip it out and put in a Racor.
 
Quick poke in the dark here. My neighbor has an Oliver with a 6 cyl GM/Detroit engine. Lets just call it a noise converter (converts diesel fuel into noise)
So, the thing kinda wanted to start, not a lot of white smoke but a puff once and a while, this thing shuts off with a cable, you pull the cable to shut off fuel thus killing the engine. The cable slipped in the lever and wouldn't let fuel into the injectors. Your Cat probably has an electric solenoid valve that is possibly failing or now has just failed, I think a failing valve like this "might" account for the hunting issue. On the other hand, my Case skid loader hunts when it's running low on fuel.

Just .02
Dave
 
Your Cat probably has an electric solenoid valve that is possibly failing or now has just failed

It does have and they do fail but loss of prime is much more common. Easy to check the shut off solenoid, 2 bolts and its off. Then try to start it, if it does just poke down the hole to shut it off.
 
I agree with GaryE - that's akin to saying chevy 350s are lousy engines.

Nope, that's like saying apples come apart just as easy as oranges...

3204, 3208, 3116, 3126 are all lousy engines. They often break before their time, give trouble, need special tools, don't make much power, eat more than some other engines, and cost a LOT to repair. And that's coming from a cat lover. 3406 and C series all the way, and for a toy I'd love to have a 1693:drool5:
 
in my opinion the 3208 was a throw away engine by design, bore type block and all. that is not to say that they could not be used in specific
applications to good effect, just mostly in trucks they were a 100k mile engine and then exchange the little joker.

3406 was probably their most successful truck engine, before that
the 1693 was a monster that would make a million miles without issues if it had decent maintenance, although the 1693 was heavy as hell, and we used to call them the 5000 dollar wonder.

everything seemed to cost 5 grand, a head? 5 grand, and injection pump? 5 grand, etc etc. luckily unless you were an idiot they didn't seem to ever need parts.

back to the 3208, i doubt seriously it has slipped time, the drive gear fits on a taper and is very tight, only way for it to slip is a siezed pump.

check the shutdown solenoid as alluded to earlier, and because the engine has not been in production trucks for a great number of years it is very likely you have a bad fuel supply line somewhere, or have something caught in a fitting or sediment somewhere blocking between the tank and lift pump.

lift pump is also something to look at, as a previous post.

basically you got very good advise, so far

just start with the simple stuff first

check the fuel solenoid
check for prime
check all lines and hoses for obstruction
check the lift pump
check filter housings
crack a few injector lines while bleeding

also the injection pumps themselves had their issues with failures as well, i used to go out and replace them with some frequency.

bob g
 
I was able to purge some air out of the injector lines earlier and get it to start finally. Once started it was actually running pretty smooth for a few minutes then starting hunting again.. not much.. maybe 100 rpm fluctuation.

I shut it off and tried to re-start a few minutes later and it would not start. I also noticed some fuel dripping down the bellhousing so I think we have a leak. I will have to take a better look tomorrow in the daylight.

Thanks to everyone for the help and I will update tomorrow if/when I find out more.

Andrew
 
I was able to purge some air out of the injector lines earlier and get it to start finally. Once started it was actually running pretty smooth for a few minutes then starting hunting again.. not much.. maybe 100 rpm fluctuation.

I shut it off and tried to re-start a few minutes later and it would not start. I also noticed some fuel dripping down the bellhousing so I think we have a leak. I will have to take a better look tomorrow in the daylight.

Thanks to everyone for the help and I will update tomorrow if/when I find out more.

Andrew

What leaks fuel out can also let air in. Fix the leak and you should be good to go. At least you know you don't need to keep hitting it with ether to make it run.
 








 
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