calliesman576

I'm smelling a light gas smell after I drive my 1986 Toyota 22R. As well in 5th gear I'm noticing a slight shutter while accelerating up hills. Could this be a sign that my fuel pump is beginning to go out. I have not looked it yet for signs of leaking. I plan to do that this afternoon.

the_supernerd

The shuttering could be many things. If your fuel pump cannot produce enough flow anymore, then the carburetor could run lean at full throttle, but it could also be a carburetor problem, ignition system problem, or timing. If the timing is way off or the truck is running really rich then you might also smell fuel. The smell could be old fuel lines, evap system lines, leaking carburetor, fuel pump, fuel tank, or filler neck. I would immediately pop the hood after driving the truck and try to sniff out the fuel smell before it goes away. That will tell you where the problem is, but check all of the fuel hoses anyway. Take off the air cleaner housing and check the carburetor for leaks and cracked hoses. There are vent holes in the bottom of the fuel pump, and in my experience it will usually start dripping fuel out of those holes while the truck is running.

calliesman576

Thank you. I'm also experiencing back firing through the tail pipe when letting off the gas pedal. Could this be connected to the gas smell as well?

the_supernerd

It could be, but I would start by checking your timing and ignition components. Make sure the vacuum advance is holding vacuum on both diaphrams. If the spark plugs, wires, cap, and rotor look old or you do not know when they were last replaced, replace them. A valve adjustment is usually a good idea at this point, also. A fuel cut solenoid not working properly can also cause the popping. Most older vehicles that I have purchased over the years smell like fuel as the fuel hoses and evap hoses need replacing. They are almost always overdue for a tune-up also. If the carburetor has never been rebuilt, then that could also be a possible source for all of the problems, but I would start with the simplest things first.

wyoming9

iTrader: (1)

Might be one plug or more not firing dumping unburnt fuel into the exhaust that is what you may be smelling.

It would also explain the poor performance .

calliesman576

Thank you. I'm planning on replacing the plugs next weekend. Any suggestions on type. This truck has 211,000 original miles. I bought it from the original owner who is now 65ys old. It was garage kept. He told me he kept all maintenance performed from the day he bought it. I just don't know about the plugs. Not sure when they were last changed.

the_supernerd

If I remember correctly, the manual for my '87 recommends either Denso or NGK, and I want to say the NGK number is BPR5EY. I have had good luck with those, gapped properly. Take a close look at the old plugs, as that could help tell you what is going on in the engine. Look up pictures of spark plug wear and compare your plugs to the pictures, or post pictures on here.

ChinkTruck

Back firing when you let off the gas on carb trucks is almost always a vacuum leak on the intake side. With the truck running take a can of carb cleaner and spray around the intake manifold, if theres a leak you will hear the rpm change as it sucks in the carb cleaner, pin point the leak and repair. this is where i would start. Also check your exhaust recirculation pipe, located on top of the exhaust manifold, it injects hot exhaust gasses back to the intake and a leak here will act the same as a intake leak. Dont forget the reed valve and its components located under the intake manifold.

calliesman576

Thank you. I will do that this weekend if time allows.

ChinkTruck

also I should have added, this is a symptom of running too lean, so its also possible its a bad or way out of tune carburetor so if you can't find a leak it's probably the carb.