I have a 97 Dodge B1500 3.9 V6. It won’t start. I’ve changed; the plugs, Coil, Cam Sensor (bottom of D-Cap), Ignition Switch assembly , Battery, Fuel Pump, and cleaned the IAC.
I have 60 psi Fuel at the rail, Good spark, 130 psi Compression across the board, and no ideas left. HELP
So, it’ll run for a few seconds if you spray ether into the intake?
It’s sound like it wants to start, but no. Spraying fuel in the throttle body does nothing.
I have also replaced the Auto Shutdown Relay and the Fuel Flow relay.
Any Check Engine Light or codes present?
If it won’t start with fuel in the intake then you need to verify there’s a healthy spark present at the plugs.
How many miles on this thing? That 130 PSI of compression could be a cause for concern as it is too low. Ideally you want up in the 180s so 130 points to a looming problem.
No Check Engine light. I did pull a P0320 code with the ignition switch on. I am getting spark so the crank sensor must be working. There is 166,532 miles on it.
Broken timing belt?
It almost sounds like the car is flooding. I pulled the plugs out today and they were a little black but wiped off easily
Barkydog - But I will check it.
If worse comes to worse, you might consider pulling the plugs, giving each cylinder about a tablespoon of motor oil, reinstalling the plugs, and attempting a start then.
If the engine fires up then the problem could be due to the lowered compression. In theory a 130 should run but that’s not always a given.
I’m reminded of the Dodge a dealer I worked for had on the lot that would not even cough one morning. Compression on 8 cylinders varied from about 90 to 125. The vehicle was given the motor oil treatment and it fired right up with compression returning to the normal 175-180 and never a problem again.
The lot porter had fed the vehicle too much ether one very cold morning while trying to start it and the starting fluid had washed the cylinder walls down which in turn lowered the compression.
Have you checked the valve timing and spark timing?
Sounds like the timing chain jumped a few teeth. The 3.9L timing chains are known to stretch, there is a guide/tensioner available so the replacement chain won’t slap the timing chain cover as it wears.
Align the crank to TDC on the #1 compression stroke and check if the distributor rotor is aligned with the terminal for cylinder #1. If not the timing chain may have slipped.
sounds like timing chain to me too…
Ok Sorry for the delay. Just checked the TDC and its right on the money. I also added oil to the plug holes. It started for about 15 seconds and died. Ran really rough though.
do you have an electronic ignition box?
Not Sure. I just replace the ignition switch assembly .
no this would be a box under hood somewhere, may be called ignition module or something. just has a plug going into it. they can cause all kinds of weird problems then eventually you can t even sart up. can be hard to diagnose and they will sometimes test ok at the parts store even if they are bad. make sure they test it a few times. if you find one they can be removed easily and many parts stores can test them
I always just called it electronic ignition box
my manual calls it the electronic control box
The coil is triggered by the PCM on the firewall.
Good spark or intermittant spark? Have you replaced the crankshaft position sensor? There are still a number of possibilities but the CKP sensor is the simplest.