QuestionHi Roland,
Do you have any more good advice I can try so far it all checks out, I did order a ignition coil so I will try that next. Also I did notice today as it started to die while driving if I gave it more throtle it would still lose rpm but it would not die completly. If I did not give it more gas it would die and I would have to crank it again. I have checked the fuel pressure while driving and it did not change when the engine dies.
Thank you
Urban-------------------------
Followup To
Question -
Hi Roland, Thanks for the prompt reply, I will check those items tomorrow. It is a 3.8L, we have also checked for codes and there is no codes, that is what have stumped my mechanic friends, any help is greatly appricated.
Thanks again
Urban-------------------------
Followup To
Question -
I have a 1996 Town and Country that stalls when it feels like it, most times it will start up right away, maybe I have to start it a few times.Then it will run fine for a while again.It seams to happen more when it is hot, If I drive 10 miles and then shut it off, come back a few minutes later it will almost always stall right away. We have replaced the cam and crank sensor, disconnected the knock sensor and replaced the computer,and auto shutdown relay.
Thank you for your help.
Aloha
Urban
Answer -
Hi Urban,
I surmise that you have the 3.3 or 3.8L engine, correct?
My inclination is to suspect the coolant temp sensor might not be accurately reporting the temp to the engine controller and thus giving an incorrect mixture. You can check the resistance across the terminals of the sensor: it should be 7,000 to 13,000 ohms when cold, and 700 to 1,000 ohms when cold. Another possibility is that the egr valve is sticking ajar which will prevent a restart/idle situation. So look at the stem inside the saddle on the valve that has the slot in it for visualizing the movement and use a flat blade screwdriver to open and shut the valve manually to see if it moves reliably in and out. You might want to spray some WD-40 on the stem to assure smooth movement. Lastly, I would want to see if any trouble codes have been stored in the engine controller.
The most useful thing to do would be to try to get the fault codes that may stored in the engine controller memory to readout. Try using the ignition key: turn it "on-off-on-off-on" and leave it "on" (doing this quickly, no longer than 5 seconds). By "on" I mean just the normal position when the engine is running, not the cranking position. The 'check engine'light will remain on when you leave the key in the "on" position with the engine still not running. But then watch the 'check engine' light to begin flashing, then pause, flashing, pause, etc. Count the number of flashes before each pause and keep track of the numbers. Repeat the readout and verify the counts are correct. Then group them in pairs in the order that they came out, thus forming two digit numbers. You may notice that the pause is shorter between the digits of a given number, and longer between the numbers themselves. Then send me a 'follow-up' question telling me the results of your readout. By the way, 55 will be the last number (two groups of 5 flashes each) and that is the code for "end of readout".
I have the troubleshooting manual for several engines and we can look up the possibilities of what is wrong based upon what fault codes you show. When you write back tell me what engine you are driving.
There is also an essay on fault codes at the site:
http://www.allpar.com/fix/codes.html
which gives the meaning of the code numbers. But then you need to get specific info for what exactly might be the diagnostic tests or parts to replace to complete the repair. If this approach doesn't produce fault codes at all*, not even a 55, then you will have to go to a good tune-up shop where they have a more sophisticated code reader in order see if there are any codes. You should be able to get a readout for under $50.
So those are some ideas for you to consider. Let me know what happens and how I might be of help.
Roland
*The ability to get the codes yourself with the ignition key was eliminated when the OBD-II system came in, around 96 or 97 so you can't be sure until you give it a try on your 96.
Answer -
You are welcome, Urban.
The "no start without codes" is a tough one. One other possibility is a flakey coil pack. Have you checked for spark when it won't start?
One experience I had might be relevant. I had a similar situation with my 2.5L 4 cyl engine. The problem turned out to be a MAP sensor that was reading inaccurately but not so much as to set a code. It took a Diagnostic Readout Box II in the hands of a tune-up mechanic at a Chrysler dealer to detect that one.
I would appreciate knowing what the answer is when you find it.
Roland
AnswerHi Urban,
I hate to see you throw more money at parts that may not solve the problem (e.g. the coil pack). Why not check the resistances of the primary and secondary coils at the time the engine is acting up? Carry an ohmmeter with you and when the problem begins remove the electrical plug for the coil pack. The 12V supply comes in on the upper right pin. So measure the resistance between that pin and each of the other three pins. Zero the reading of the ohmmeter to get an accurate reading. Then see if you get 0.51-0.63 ohms on each of them. Then remove the spark plug wire pairs, one pair at a time so you don't get them mixed up, and measure the resistance between the pairs of spark towers. It should be 11,600 - 15,800 ohms for the Diamond brand, and 11,500 - 13,500 for the Toyodenso brand. If it passes that test when it is hot and acting up, then presumably it isn't the coil pack.
I still wonder about MAP sensor not being reading accurately. Maybe if you took it into a Chrysler dealer after driving it enough to get it warm and you had an appointment their tune-up mechanic can put a DRB box on it and see what sensor looks bad. When you don't get a code there still could be a specific voltage or other physical measurement that will be the clue you need to solve this one.
Roland
