Quote:
Originally Posted by tomtom72
Dennis, no problem. If you get a chance look at the hose that connects the MAP sensor to it's vacuum source at the rear of the plenum. Something is giving the ECM fits and I suspect it is an "input" signal.
Okay, humor me and my 1/2 a$$ed mechanical non-existent diagnostic skills! LOL I'm thinking that some blow by oil got from the plenum into the MAP hose, or the hose is collapsing under high vacuum conditions ( like closed throttle coast down?). Look to see liquid oil in hose or even getting up into the sensor itself. Or that the hose has become soft from oil and is collapsing under high vacuum. Either one would throw off the Hg reading to the ECM and proly mess up the fueling? Does she do this miss thing at WOT way up in the 6k rpm range also? Okay this is the only other off the wall thing I can think to write down here. Otherwise, yea the TPS voltage and look to see that the TPS voltage is responding from 0% to full wot. Yes to the IAC, and I have to vote maybe on fuel pump performance, but check the pressure regulator hose for gas.
See you in the spring, unless I figure something out that is worth while typing here! 
Tom |
Symptom being described sounds very similar to what I had experienced 2 years ago.
MAP sensor hose between the sensor and the back of the plenum is a hard plastic piece w/ rubber fitting at both ends. Mine were replaced with a soft hose. With age this hose got softer and at high vacuum during decelleration the hose would collapse cutting off vacuum reading for the MAP sensor. Trying to accelerate at certain condition would make the car buck.
Check and make sure you have a hard plastic hose.