I have a 1993 Toyota Liteace, the engine dies every few minutes
(Note: it only happens when im driving down the road, i can let it idle for an hour but not stall, only when driving )
The vehicle has approx. 200k kilometers, I have replaced the Ignition coil, High tension wires, spark plugs, but the problem doesn't go away.
I forgot to mention that the engine will only start back up if i let it rest for a few minutes after it stalled.
How old is the fuel filter? Air filter? Fuel pressure OK?
Fuel filter is around 1.5yrs old, air filter is around 1yr old, i forgot to mention that its carbureted not F.i. and it just has a mechanical fuel pump bolted to the block
Fuel filter is around 1.5yrs old, air filter is around 1yr old, i forgot to mention that its carbureted not F.i. and it just has a mechanical fuel pump bolted to the block
This does sound like a fuel delivery problem.
Carb may be plugged up internally, maybe time to rebuild it if it has not been done in recent years.
Also verify that the mechanical pump is working OK. Driving requires more fuel to be delivered than idling. A quick test of the fuel pump is to pull off the fuel line from the carb and put it into a container. Disable the car's ignition - if you have a distributor just take off the coil wire. Or, pull out the ignition fuse. Crank the engine and you should get strong pulses of fuel into the container. (There should be a factory spec for how much fuel it is supposed to pump, but if it looks strong it should be OK.) If fuel is just a weak dribble the pump is bad.
You can also check the pressure with a vacuum gauge since most of those can also be used to check low-pressure mechanical fuel pumps. On most carbureted vehicles you should see 4 to 6 PSI pressure. Also not a bad idea to remove the pump and check to see if it is leaking fuel into the engine oil as it would do if the rubber diaphragm inside is leaking.
If the pump is original (30 years old!) I'd probably just replace it, the thing couldn't have much life left in any event.
https://www.howacarworks.com/fuel-systems/checking-a-mechanical-fuel-pump
https://www.liveabout.com/common-mechanical-fuel-pump-problems-726177
The Carburetor has been cleaned not too long ago, i will check later how much the fuel pump will give as i'll remove the hose and with a clear bottle,
But the engine will only start back up if i let it rest for a few minutes
When it won't start back up try spraying some starting fluid down the carb. If it still doesn't fire up you have no spark, if it does fire up you have no fuel.
Actually, last time i started it, it just keeps on crankin, i checked for spark, there is spark, so i decided to dribble some fuel to the float bowl and deep to the carb itself, then its the only time it started.
So i am indeed convinced that im havin some fuel delivery issues
Regarding the testing of the fuel pump, i think somethin is indeed up with the fuel pump, first few pulses it gives a strong pulse of fuel, not much later it only dribbles fuel,
Most likely fuel pump failed or somethin is cloggin the fuel pump
Sure sounds like it. Either the pump has a problem or there's a clog. There's probably a nylon screen ("sock") on the fuel pickup in the tank and that could certainly clog up over 30 years.