What causes a 1993 Ford E150 custom van to shutter and buck when giving gas after slowing down when it idles and takes off good and sensors and plugs and wires are new?

Answer 1

EVAPORATIVE EMISSIONS CONTROL SYSTEM: If you smell fuel vapors after stopping the engine, outside of the vehicle. Check your EECS system, which consists of 1. Purge control valve: check operation and hoses 2. Canister for fuel vapors: check for cracked case and cracked vacuum lines. 3. Fuel tank vapor vacuum line: from canister to tank. Blow into it, you should have very little flow through it after the tank is full of air. (DONT SUCK ON IT, LIKE POISION) 4. Fuel tank vent line: from tank to gas filler pipe. This is very hard to check, and is probably your biggest problem. If you smell fuel vapors after stopping the engine that are very strong after filling the tank, back by the fuel tank, this is probably your problem. Use a mirror and a flashlight to check the vent hose. Check where the tubing connects to the tank. Look very carefully and move the tubing when checking. Also feel around the tubing for cracks. This hose is 3/4" rubber tubing, you will probably have to use heater hose to replace it. There is a hose clamp, with a 5/16 hex head on them. Very hard to remove, use an old fashion spring clamp to replace it, much easier. I had the same problem, and it almost drove me nuts. Joedi