Question-------------------------Question - Hey and thanks for getting back to me . the car has a 3.5 and will not run at all ! was running and I truned it off and hasn't run again and not sure what they have checked . It don't show any codes but it did run fine till now . two plugs fire sometimes but not like it should . It will backfire sometimes but thats it
Followup To
I have a 1993 Chrysler Concorde that truns over but don't start. It's not firing right . Took it to dealer and they don't know what it is computer says it's ok . Didn't jump timming so what can I do ?
Answer -
Hi Barry,
I am unclear about the exact starting behavior of the car. It sounds like you sometimes can get it to start, but sometimes not, or does it have some other pattern of starting/non-starting? I ask this because you were able to take it to the dealer under its own power and that you either left it there, or drove it home, I can't be sure.
So please clarify that for me, and also do you have the 3.3 or the 3.5L engine?
The no start or hard start without any codes requires some greater finesse. I had such a situation where the problem was one of the sensors was inaccurate but not so much as to set a code (specifically the MAP sensor), which was diagnosed properly by a Chrysler tune-up mechanic using the detailed sensor value readouts via the Diagnostic Readout Box II (DRB II). So I guess one question is did they just do a quick and dirty code readout, which you can do yourself by the way, or did they look at the details of what the sensors were reading? Here is how to do a code readout for future reference (my boilerplate response):
"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.
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."
So please let me know where things stand with the dealership and the car's behavior. If you can limp along for awhile you might try that and check for codes periodically until one pops up. There are also parts of the engine operations that aren't monitored by the engine controller code system (exhaust system, fuel pump, vacuum leaks, spark plugs, valve/compression situation, for examples) so it may have to be checked over by a skilled Chrysler-experienced tune-up mechanic equipped with a diagnotic readout box that shows all the details of operation not just the codes.
So let me know what is going on with a little more detail and perhaps I can give you some more suggestions.
Roland
AnswerHi Barry,
If you have the car at home (rather than it is still at the shop) then I suggest that you take a look at the spark quality by pulling one of the plug caps, inserting an insulated screwdriver so the tip touches the center contact wire inside at the bottom of the cap, then hold the handle and cap assembly so that the shaft of the screwdriver is 1/4" from the cylinder head or other grounded metal surface while a friend tries to crank it over for 5 seconds. See if the spark is consistent and strong. If not, then further checking of the spark coil is called for (write back if that is an issue).
The second area would be to check the egr valve to possibly be stuck ajar which will prevent the engine from starting or idling. You will need to remove the valve to check it. Finally some sort of vacuum leak via one of the hoses attached to the intake manifold being disconnected or cracked, or a PCV valve hose crack or valve stuck open. You can use the underhood sticker as a road map to follow all the lines checking at both ends and beyond each attached component to the end of the vacuum chain.
If the spark timing is o.k. then those are the most likely reasons for what you describe.
Roland
