Hi Guys,

I have a 92 b2200, carb, manual. Ive been searching all over the web. I found a post that described exactly the same issue, but unfortunately no one responded with the solution. Any help much appreciated

Background: 7 year ago, 40k miles ago i did a big overall. Filters, fluids, cap, rotor, plugs, wires. About 3 years ago the original mechanical fuel pump began leaking so i put in a new one from autoz.

Problem: Truck starts, idles, and revs just fine. I can down shift engine break whithout issue too. The issue just started to happen avout 4 days ago after 8 years of ownership. Issue occurs in all gears 2nd, 3rd, 4th and 5th gear, when engine is cold and warm. The issue is when im driving and accellerating it bogs down randomly. At times i can push the pedal to the floor with almost no acceleration. As if im going up a big hill in to high a gear. I can drive for 10 minutes accelerating just fine, then it will start acting up. The odd thing is i can push the clutch in while its bogging and the engine revs up just fine.

its so strange. Any help or diagnosis recomendations and questions are much appreciated.

 

Check that distributor/timing is advancing.

 

Thank you cusser! What is your prefered method to check? I havnt worked with timing before

 

Timing light on #1 spark wire. Should be about 6 BTDC at idle, about 30 BTDC at about 3500 rpm. See B2200/B2000 Timing Check

Check fuel filter under the air cleaner too.

 

I am having the same issue. does fine until about half throttle or pulling a hill not matter how small or big. Does it in any gear. Seems to be more prevelaint in higher gears. Anything more than half throttle begins to choke and act like the engine is shutting off. I back off throttle an picks right up again.. like nothing happened. Truck won't pull itself faster than 65 to 70 without going down hill. I've checked multiple times for vacuum leaks. I found one large one where the feller who owned it before converted to the Weber manual choke. Retimed the engine. Adjusted carburetor and it seemed to help with idle an gas mileage but still won't perform under any load at all. I'm completely stumped. New wires plugs rotor cap. Could this be a vacuum advance issue?

 

"Could" be a timing advance issue, like timing OK at lower rpm but not getting full advance of like 30 BTDC at about 3500 rpm. But that should be easy to check with a timing light after painting a 30 BTDC mark on the crankshaft pulley.

I'd also check fuel FLOW, your issue fits symptoms of fuel starvation. Change the fuel filter, might be clogged and preventing full gas flow, should be passenger side of engine compartment on 5-speed truck, cut open the old filter and check for rust inside it. Often on these trucks, there is rust in the fuel tanks, so the fuel "sock" gets clogged, cutting down gas flow, and filter gets clogged too. Yes, the truck bed must be removed, pushed rearward, or tilted for access to top of the gas tank (unless one wants to drop the fuel tank). I like the tilt method myself, see my write up of how to do this here B2200 Fuel Sender Replacement

I also have a Weber carb on my 1988 B2200 5-speed, about a dozen years now, but mine's electric choke which plugs into rear of alternator.

 

Thank you, sir. Since my previous post I have found a small vacuum leak underneath the choke cable where it attaches to the lever. When I sprayed some carb cleaner near that area the truck idles down significantly. I will definitely look into some fuel issues. I'm pretty confident in the timing and and where it is set right now. The fuel filter I have some questions about though. The only fuel filter I can find is a clear plastic one that's an inline fuel filter that is about a foot from the carburetor on the intake line. I replace that already with a new one the old one didn't seem to be very dirty at all it had some rust color and the gas was yellow so I could imagine the truck was sitting for at least a short period of time. and I check the timing with a light and it seems to be advancing just fine. I drove the truck from Helena to Boulder Montana today which is about a 30 mile drive just to see what would happen. When the truck is cold it seems to run pretty well but as soon as it warmed up a little bit as when it started doing the chuggin real bad and it's almost to the point where I can't pull any Hill at all until I'm in second gear and it's wound up tight. I suspect you're right in saying that it is a fuel issue I'm just not sure where to start. I guess another question I have is the the leak in the carburetor where it is sucking in air right beneath the choke lever can it affect the engine that much. And make it want to die under any load? This truck has a mechanical fuel pump on what are the symptoms of a bad fuel pump?

 

Does the fuel sender still apply with the mechanical fuel pump? Sorry sorry if my questions scene obvious but I am no mechanic. Thank you again

 

With a mechanical fuel pump, there still is a fuel sock inside the fuel tank, next to the the sender float. It should be attached to the steel fuel tube, but on my truck it was simply on the tank bottom, it had fallen off (I bought a factory replacement sock).


Most times a vacuum leak causes bad idle and low rpm operation, masked with higher rpm.

I'm wondering about what you said about running decent when cold and getting worse as it warms up, like maybe your choke butterfly is not opening. 1. Is the choke (choke heater) plugged into the rear of the alternator like it should be?? 2. When warmed up, take off the top of the air cleaner housing; the choke butterfly should be essentially vertical.

OK to attach pictures here too.


My B2200 truck has gone through a few mechanical fuel pumps in the 24 years I've owned it (lifetime warranty); those all leaked gas externally and I could smell gas. But I suppose a pump could deliver less output. Remember - there is a plastic spacer under the mechanical fuel pump.

 

i’ve replaced fuel pump, both fuel filters, added injectors cleaner to the gas tank, replaced ecu, and replaced fuel pressure regulator, spark plugs, and new injectors.

my problem is when i drive i have to ease on the gas to get up to speed and even then i feel like i have no power. going up a hill was a struggle. also when i press heavy on the gas the car bogs and wants to stall and back fires. i’m at loss as to what else it needs. please help !!