3208 engine runs but not good

Check the fuel return line back to and into the tank(blow air into tank with cap off).
This line is a constant bleed line to take care of any air the pump picks up.
Later Bob

seems like a logical answer, i wasnt able to blow that line out, but i will tomorrow night. right now its blazing hot out there and i just started my laundry haha 😊 i did notice that the return line wasnt putting much back into the tank. just a few drops at a time. thanks for the advice!

Hi jaker65,
I posted a possibility on this thread linked below a while back.
Hope this helps.
Cheers,
Eddie B.

http://www.acmoc.org/bb/showthread.php?18284-Cat-225-fuel-trouble&highlight=sleeve+metering+injection+pump+air+bleed

Hey Eddie
The post did help out some. I got the aair out of the fuel lines sand fired up almost sad soon as I turned the key. It ran fine, I opened up the bolt on top of the pump and got the air out there. But after running half throttle for 5 min I let it idle, then wafted a min the rpm's started to jump again. I made sure the fuel return line was clean and got a nice steady flow goin back into the tank. seems like it is running out of fuel or starving itself. When the rpm's start to jump, I go and prime the engine with it running and it smooths out. But only for a little bit. I took the main line off and blew it back out and made sure it was clean was well. So far what I have done seems to have made it run better I can say that. Thanks again for the help

Hi jacker65,
good job there mate.
Seems like you may need to check for restriction in the fuel tank return line fitting and stand pipe at the tank itself as you still seem to have the problem to a lesser degree.
Next make sure there is no restriction to the fuel supply as, the fuel transfer pump is bolted onto the front of the injection pump so the entire inlet side fuel lines, screens and the fuel filter itself are under vacuum-low pressure- any leaks here will cause aerated fuel that will slowly build up again in the pump body.
Maybe put a clear section of fuel line at the pump inlet to observe for aeration.
Failing that the pump will need to be removed and the front bush checked for wear also to reseal the transfer pump section bolted to the front of the pump itself.
Cheers,
Eddie B.

Hello jaker65
Yer as edb said the fuel supply upto the fuel injector pump is under low pressure (vacuum),
subject to line and filter restrictions.
The higher the restriction the greater the possiblilty on air entering the system resulting in
low power, unstable engine revolutions and hard starting.
As edb said I to had a clear plastic tube to test for air entery before the fuel pump.
Found on many occasions that fuel lines and fittings were loose or holed and at one
time CATERPILLAR were getting filters through another manufacture and the filter head
seal was under size and alowing air to enter.
Goodluck
Gary

I had a poor running Louisville once that had a 3208 in it and initially i got a drum and plumbed it straight into the fuel transfer pump. The engine then ran fine never missing a beat, so i then sorta knew where the issue wasn,t!!

At the rear of the RHS head there is a block where a couple of fuel lines are and turned out there was a small piece of what looked like rubber maybe from a hose or something like that and it was caught where the 90 degree elbow was at that block and while you could blow it with air and it sounded wide open when it had fuel being drawn through it it would jam and restrict the flow.

hey everyone,
well i am back with more results. i got the engine running pretty good now. yesterday i went through rechecked all the fittings and lines and the breather line on the fuel tank itself. everything was okay. i took the filter back off, dumped out some of the diesel fuel and filled it up full of injector cleaner. re primed the fuel system, and it started up. i threw a brick on the gas pedal and let it run at 1,000 rpm for a good hour. took the brick off and let it idle. so far so good, i let it idle for a good 30 to 40 min and it never sputtered once nor jump in rpm. i also did bleed the air from the injector pump once again. i must not have got all the air out the first time. i then hit the throttle and quickly released it, the rpm went back down to the normal 500 range and didnt jump at all. i went back out today, started the truck up, let it idle again with no problems, i hit the throttle and held it up for 5 min, came back down and didnt jump. so i let it idle again, then it did jump the rpm range so i held the throttle down for 3 min, and turned out okay. didnt jump anymore. so am i safe to assume that most of the problem is gone or might there still be some air in the system? also is the fuel filter suppose to be full of fuel when running or only half full? last time i took it off after running the engine, it was only about 3/4 full of fuel, but i did hear it suck air when i broke the seal and did hear some of it drain back down into the tank.

Hi Jake,
the fuel filter should be full of fuel.
By your description you may have a part blockage down stream from the filter as the only suction should be from the head of fuel from the filter location to tank fuel level.
Check the tank breather system as a blocked breather will cause big suction in tank similar to your description.
Can you get to see the pick up in the tank. Sometimes fluff or rag, grass etc can wash against the pick up and block/restrict it and then clear away if you back blow with air etc.
Some pickups can have a sock type strainer fitted and this could be part clogged with lint/crud.
Not the first time a stand pipe/pickup tube has part fractured from vibration and cause air leaks.
Can you remove the stand pipe and check its integrity at the upper end--could also be rust holes in this pipe.
Cheers,
Eddie B