crawl4l

so here is my situation: i recently installed a weber carb on my yota(its a "ca legal" one cause i live in ca) and alot of the vacuum lines and pcv hose and whatnot are rerouted or removed cause of the new carb. after a couple days it now acts like it wants to keep running after i turn the key off but it dies in a few seconds or so. i probably didnt put a hose or line in the right place? if anyone has heard of this i need help!

82blueyota

It's called dieseling,multiple things can cause this. It is verry bad for your motor.You probably have a hot spot in one of your cyllenders,causing fumes to ignite.

82blueyota

I stole this
This condition can occur for a multitude of reasons:

Built-up carbon in the ignition chamber can glow red after the engine is off, providing a mechanism for sparking unburnt fuel. Such a thing can happen when the engine runs very rich, depositing unspent fuel and particles on the pistons and valves. Similarly, non-smooth metal regions within the piston chamber can cause this same problem, since they can glow red. It has also been suggested that an improperly rated spark plug can retain heat and cause the same problem.
A carburetor that does not close entirely can contribute to running once the engine is off, since the extra fuel and oxygen mixture can combust easily in the warm piston chamber. Similarly, hot vaporized oil gases from the engine crankcase can provide ample fuel for dieseling.
Incorrect timing.
An engine that runs too hot or too lean may produce an environment conducive to allowing unspent fuel to combust.
An idle speed that is too fast can leave the engine with too much angular momentum upon shutdown, raising the chances that the engine can turnover and combust more fuel and lock itself into a cycle of continuous running.

crawl4l

alright looks like i got a checklist for tomorrow. thanks a bunch

algranger

I bet its the fuel cut solenoid in the new carb.

peow130

this is usually the case, 99% of the time.

crawl4l

so are you saying weber carbs come with bad solenoids? or does it need to be adjusted?

peow130

Not necessarily, but is yours hooked up properly?

crawl4l

that'll be the first thing i check tomorrow and i'll report back. thanks guys

SC81YOTA

Make sure your engine timing is not set to high. Also make sure your distributer vacuum hoses are hooked up correctly. Once I checked mine and corrected the situation all my problems went away. I had to switch one vacuum line then I corrected my timing. All good now. Read to see which ports do what on your new carb and compare it to your distributer. Its frustrating but an easy fix

crawl4l

so today i took the carb off and look at everything to make sure there wasn't any lines i missed. i didnt see any other ones but i rerouted where the hose from my pcv valve went. i also pulled the plugs and theyre nice and black. but the choke was out on the stock carb and i know the p.o. played with it to get it running good. anyways the dieseling problem seemed to go away but i didn't drive it just warmed it up to operating temperature and turned it on and off a few times. need to get a new timing light and check vacuum leaks tomorrow. also now when i tune the carb to the directions settings, when i start to back the idle screw out it wants to die. i'm lost on that one