Chrysler Repair: 98 Plymouth breeze: uneven when coasting,dieing at high speed, throttle position sensor, exhaust gas recirculation valve

Question
Roland,
I have had fault codes checked and nothing has shown up at all. I am lost and everytime i take it to a shop they say they cant figure it out. the engine size is 2.0 and its a 4 speed transmission. It doesnt always happen its random, so could it be the throttle position sensor just be misfiring once in a while. please help

Answer
Hi Matt,
Uneven coasting dieing at high speed, with no fault codes, is a challenge. There are about 18 different sensors and systems that might be checked over according to the '98 powertrain troubleshooting manual that I have. One component that I am always suspicious about when you have trouble coasting with the throttle valve closed is the exhaust gas recirculation valve. You will find it at the rear of the engine on the corner that is closest to the driver. It has a pipe that comes to it from the exhaust manifold and a pipe from it that runs around to the air intake manifold near the throttle body.
So locate the valve in between those two pipes, it has a round top with a vacuum hose attached to it, then a saddle-shaped spacer and then the valve body proper. If you look inside the spacer you will see a rod with a groove in it. That is the valve stem. Take the tip of a screwdriver and insert it in the slot to use as a lever to move the rod in and out of the valve body against spring tension in one direction. See if the spring is firmly pushing the stem all the way "home" which is the valve closed position. If it seems to stick partially ajar then take some WD-40 or other spray lubricant and spray the valve stem at the point where it enters the valve body. Then lever the rod again to make sure it moves freely. Finally, start the engine and rev it several times while observing the slot in the stem to watch it move and to make sure that it opens when you rev it to 2500 rpm, and then that it closes promptly when you close the throttle valve. Then drive it and see if that helps solve your problem. That valve will cause the engine to run too lean if it sticks ajar either when you are accelerating hard with the throttle open or deceleraating with the throttle closed.
If not, then the best thing to do is to check thru all the 17 other items in the list. I can copy several dozen pages at 8 cents per side and postal mail them to you if you want to try and go thru those tests. But see how the egr valve is working and whether freeing it up solves the problem.
Roland
 


Question:  When I am driving my car and i am coasting at about 35 mph car jerks like im slamming on brakes any ideas? one other thought, recently as i get to anywhere from 60-75 mph i will totally loose gas then eventually stall out cant find any answers to the problem except possibly throttle position sensor  please help....
 
Answer:  Hi Matt,
The best way to approach these issues is to do a readout of the engine controller for fault codes, and you might also do that for the transmission controller. You might be able to get if for free an an Autozone or other parts store. Or a shop will likely do it for under $40. These codes begin with a P and have 4 digit numbers. Get those numbers and any suggestions as to what they mean and what is the proposed repair and costs. Then write back and we'll compare to the manual and I can adise you on doing it yourself.
But getting the fault codes if the only efficient way to move on these problems. Tell me which engine and transmission you have when you write back.
Roland