Hi, When accelerating from a stop or from below 10 mph, I experience a hesitation just after the gas pedal is depressed. The engine stays running, but cuts out almost entirely for 3 seconds or so, and then picks back up again. Also, the idle runs in an uneven way, high then low, over and over. This sometimes evens out once the car has been running for a bit. The following has been checked: - throttle body cleaned out - throttle switch cleaned and then carefully reset by a dealership technician - jetronic ECU leads tested system grounds and throttle switch resistance checked out correctly - gasoline sample checked for water -- gas is good - replaced the blade fuse (25) that is near the ignition coil I'll also mention that I replaced the entire throttle body/throttle switch with one from my parts car which had been working just fine before it was a parts car but has been sitting dormant for 2 years. This replacement yielded the same hesitation, but with a slightly higher idle, as that car had had in its running days (I figure this is just where the idle adjustment screw was set). The spark plugs were replaced 2 weeks ago when the car was stalling, and I'm about to replace the wires, plugs, rotor/cap, air filter just to take care of that all. Does it seem like it could be the Idle Air Control Valve? Does anyone know of any way to trouble shoot this? I have one in my parts car, if necessary. Also, does anyone know how to troubleshoot/listen for the fuel pumps on the 240? I found info for the 700s online, about jumping terminals on the fuel pump relay and then listening for the sound of the pumps, but nothing for 240s. Thanks for your help!
so many possibilities, but give this a try: with the engine OFF, disconnect the Air Mass Meter connector, then re-connect it... do this 3 or 4 times to rub the contacts clean. Leave it connected and start the engine. See if there is still the same hesitation. I had a similar problem with my '89 240, and found that this would fix it. I eventually made it a permanent fix by using a little contact cleaner/conditioner on the connector, and by GENTLY bending the prongs in the connector inward, so they made better contact. Like you, I also replaced the throttle position switch (mine was actually defective!), but never found that to make much of a difference....
oops... hit the SEND button too soon! I also wanted to mention that a good possibility is an air leak, causing the air/fuel mix to be too lean. Check all the hoses to be sure they are connected at BOTH ends, and there are no splits or holes that would suck air into the manifold.
