my truck worked when i drove it to work then when i went to go on lunch it wouldn't fire it started and cranked but not run i replaced distributor cap, rotor and pick up coil by time i replaced all of those things i got frustrated and took it to a shop the shop then suggested i replace the ecm because they said i was getting all power no ground so i replaced my ecm and still having the same problem now they are suggesting to replace a couple other things such as ignition switch but they aren't sure thats going to work. and i don't want to keep throwing money into it for guesses so i was just hoping someone could help me out on what to try next.
my 93 dodge dakota will start crank but won't fire on 1993 Dodge Dakota
by stephanieanne in Waterford, MI on November 05, 2013
3 answers 5 comments
ANSWER by pushrod , November 05, 2013
We will start with this; Does it have spark from the plug wires to the spark plugs? Pull a wire off of a spark plug, stick a screwdriver tip into the end of the wire and hold it about 1/4 inch away from a metal part of the engine and have someone crank the engine, do you see spark jumping that 1/4 inch gap from the screwdriver shank to the metal part of the engine??
COMMENT by stephanieanne , November 05, 2013
nope there is no spark i did that and used a tester that came up with no spark also
COMMENT by pushrod , November 05, 2013
★1993 Chry. product; find and repair open circuit, broken wire or a burned fuseable link, probably near the battery. Do you know what a fuseable link is? I assume the shop checked the basic componets, coil, coil resistor, crank sensor asd relay etc.... It aint going to be easy to find! They are hidden pretty good, wiggle test and a schematic diagram sure would be handy! FIND THE BROKEN WIRE!! Let us know what you find out.
ANSWER by ProfessorG , November 05, 2013
Are you getting power to the coil, injectors, fuel pump? that all is powered by the ASD relay. The computer has to read the signal from the pick up, (stator), in the distributer, (which you replaced), before it will keep the relay engaged, to power the coil, etc. It will momentarily engage when you first turn the key on to prime the fuel pump, then shut off until the computer has it's readings to re-engage it for operation.
COMMENT by stephanieanne , November 06, 2013
They bypassed the asd and when they did that there is no ground still going to the ignition coil or injectors
COMMENT by ProfessorG , November 06, 2013
You need B+ to coil, if you have voltage to them the computer will furnish the ground to activate the coil and injectors. That will happen very quickly, you need the right tools to monitor the ground. If you have B+ voltage to these parts and they still don't function, you need help from a mechanic/technician. The PCM needs to be checked.
COMMENT by stephanieanne , November 07, 2013
Ok i will ask the shop that my truck is at about doing and checking these things thank you and hopefully it will work
ANSWER by cardocIII , November 06, 2013
#s 1 and 2 have it right, this is nothing but the basics. The trick is the basics have changed. If you don't have spark cranking, you should then use the bi-directional tests (ASM Tests on Chryslers) and command the PCM to fire the coil and see if you have spark then. If you can get spark with the ASM tests, but not cranking then you are looking at the PCM and its primary inputs and their circuits. If you don't get spark, then you are looking at the PCM and the primary ignition circuits. This is where a fully functional scan tool, a digital oscilloscope and tools like the low amps probe come in handy. If your shop isn't using these kinds of tools and techniques then its time for a different shop.