My proud beast is acting badly. When I put the spurs to her as in going up a hill with it absolutely matted, it starts to alternately cut out and kick in rather like an exaggerated surging kind of thing. All the while it loses power, but it never dies. The plugs are fairly new and look good - no deposits and not black or white, really clean actually - and I just did a compression test which was a roaring success (152 on each cylinder, dead even). I've recently done the Sea Foam treatment (still have some in the gas tank) and checked the wires and stuff. It feels like a fuel issue. Any ideas what might cause this? I'm hoping to find the fuel filter clogged. Maybe water in the gas? I'm looking for the lowest-cost suggestions to start with
fuel filter is possible, also a good idea to test the exhaust for blockage with a vacuum gauge...the clean plugs suggest carb and ignition are good
How would exhaust blockage come to be? And how would a vacuum gauge tell you if that were the case? FWIW, sometimes the truck roars up the hill without difficulty. Doesn't seem to matter if it's warm or cold.
as an exhaust gets older the internal baffles and holes that allow exhaust gasses to pass through can corrode and collapse..looks fine from the outside but isn't flowing enough..you can test with a vacuum gauge...as you rev the engine the vacuum reading will drop to 0 if the exhaust is partly plugged and causing excess backpressure...very possible it is a filter issue
Caburetor. Adding methyl hydrate hasn't helps after 30-odd km. might take a while. I'm off to change the filter now.
Update: It was almost certainly the fuel filter causing my problems. I could barely blow through the old one except backwards wasn't too bad. That gives me confidence that I've fixed something. After a couple of days I'll know for sure. I used a NAPA #3204 filter as recommended somewhere on the forum here, and unless you're doing this in a panic I would recommend hunting for a better match. The spouts on the 3204 are at least 1mm larger than the stock filter, and the body of the 3204 filter is smaller in diameter so it doesn't fit snugly in the frame clip. So the big question: why is the filter so plugged up? Don't tell me the gas tank is next ...
20 or so years of junk can build up in the tank..also remember the tank gets drained before it gets shipped here so it is dry on its sea voyage...rust inside a dry tank is very quick to take hold
Yes, that fixed it. Didn't help much with the thrown rod bearing though The old filter was so badly plugged you could barely blow air through it. When the tank was full it worked ok but when the tank started to get low it was really bad. I'd suggest that might be a good indicator. when I got my "new" truck I changed the filter pretty much right away and it was starting to get filled with crud too.
I have had similar issues in the past, then all of a sudden it quit all together, had to replace fuel pump (expensive oem $165.00), on the second pump (only lasted 8-mo's) I investigated further and found sand in the fuel filter (before pump) so i installed a new filter there and added a new one up by carb. Its only been 3-months so I will have to wait and see, however I do have constant steady power and no faltering!!
Awesome thread guys i was having this same issue i am replacing the fuelfilter cant wait. I would shift into second and give it gas and it would almost die but would never do so.. It has no top end so lets hope this is the problem.. Rob
Lets just see if we are all having the same problem. Off a cold start the motor will bog down at higher rpm and (feel like it's) slowing down the transmission, so you shift up to the next gear and she will behave proper till the next gear gets into the higher rpm. So you find yourself in 5th doing 50 with your foot to the floor. Doesn't always have to be a cold start, but that's when I can put money down that its going to happen.
When the thing is not getting enough fuel it feels like it should just go, but it doesn't. At a certain point the fuel mixture becomes leaner. In my first Sambar this was informative because it would get a burst of power but then it would starve and suffer. When I was going up a hill I could do better if I backed off on the throttle until it had the best power. After a while it got worse and just wouldn't go enough to really drive it. The fuel pump on my '92 was loud and I could hear it rattling when I turned the key on. The one on my '94 is dead quiet. I kinda wonder if it is not as powerful because my truck has some symptoms that seem like low fuel supply at the carb, but the filter is new. Mine seems to behave a little like what Rob described - almost dies when shifting into second - but only when it is cold. It makes me wonder if the fuel pump is weakening or if there are a few rust flakes blocking the fuel line in the tank or something.
Andrew that is what i talking about you put it perfect. My truck is at a local garage now getting fuel filter, oil change, and im getting a 2 inch lift on it. My buddy is putting it on the lift to see if there is anyway we can lift it a lot more and put 15 inch rims with mud tires on it. He thinks he can make the cv joints extended. Sorry im kind of getting out of focus here for this thread. Ill let you know about the filter when i get it back. Rob
