I have a 1994 4X2 3.9L Dodge Dakota that won't start. (It was running fine until this past Saturday afternoon.)
It will turn over but it won't start. Actually, that's not perfectly accurate. I did start it on Sunday but it immediately died.
On Monday of this week, a friend of my son's came over and they got it started. I don't know how long it ran but I'm sure it wasn't long.
This friend of my son's then put a fuel pressure gauge on the fitting near the throttle body. My son read the gauge while his friend tried to start the truck. My son said he never saw the pressure go over zero. His friend said the fuel pump was probably bad.
However, I've seen some posts on this board that indicate that there might be some relays that could be causing this. Obviously, I would like to check out the relays first since that's *much* easier than replacing a fuel pump (since this pump is in the fuel tank).
So. Here are my questions.
1. What is the best way to proceed with troubleshooting this?
2. Which relay should I start with?
3. I saw a post that indicated the poster used a relay that was apparently working to substitute for a suspect relay. Is this OK for troubleshooting purposes? Are these relays the same?
4. My local Advance Auto Parts has a pump for $169.00. I thought this sounded high. However, I've seen prices all over the place on the Net with this. Is that a reasonable price for the pump? If not, where can I get a better price?
5. I've heard conflicting information on whether or not the replacement pump comes with a filter. Advance says yes but a mechanic friend of mine says no. Which is correct?
6. If the filter doesn't come with the pump, wouldn't it be a wise idea to replace the filter while I was in the fuel tank (assuming I have to replace the pump)?
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Had a similar problem with my 96 Dakota, 3.9. Turned out to be the vacuum Surge Solenoid failed. To test this, remove your PCV valve from the right side valve cover and remove the PCV valve. Start the engine, then plug the hose. If the engine stalls it is the Surge Solenoid. (Also I found out that if the battery is not taking a full charge it will effect the Solenoid. After replace the Surge Solenoid the truck ran good for a few days, then it would not start again. I tested the volts at the Solenoid and it was only at .75 volts at idle- Should be 4.5 volts. The voltage disappeared at 2500 RPM once I got it going, it should of been 1.5 volts. Found my alt. was putting out over 14 volts but after running a while I check my battery and it was only around 10.5 volts. Change the battery and trucks been running great since) Checked my old Solenoid and it had no continutiy, new one does. Maybe because of the floating volts it quit - who knows. I had made a previous posting under the Dakota forum "Vaccum Problems" that may explain it better.
If this does not help - try your Auto Shutdown Relay in the Control Center under the hood (If this had failed your truck should of never started the second time) but it is worth a try and yes you can swap any of the six relays in the control center. I usually use the fan or A/C relay when I am trouble shooting.
To check your fuel pump is easy. Turn your ignition to the on position and have someone listen to the pump in the tank. Mine makes a distinct sound. Then remove the relay from the control center. When the sound quits, reinstall the relay and if the pumps starts making noise right away the pump is still good. (when reinstalling the relay be sure to push it down squarely and smoothly - the ignition should still be in the on position, this way it will not spark. Haven't had one spark yet but just so you do not get nervous) If the pump did not start right away I would suspect the pump or wire.
As for the filter it is located on the frame and you can not buy a jobber. I went to NAPA for the one on my 96 and they said was a protected design. Had to buy right from the Chrysler Dealer. $129.00 CDN. Took it an Auto store in town to match up, found one close but the ends were unique.
Sorry to keep babbling - Hope this Helps -- Darrell
Hello, Last summer my 93 3.9 Dak about drove me nuts. Running fine one day, next day would not start. Some trouble shooting found no spark, no voltage to the coil or injectors etc. After spending lots of $$$ on computers, sensors, etc., here is what I found. Under the hood is the fuse and relay block. Remove the bolts holding the block in place. Take a nice sharp knife and start cutting away the black wrap around the wiring harness. Somewhere around 6 to 8 inches down into the harness you will find a splice of four or five red wires. I can't remember how many right off hand. Over time this splice corrodes and breaks apart. It will jump right out you because it is all green and corroded. I found this info somewhere on the net, and it seems that this is a very common problem on this generation of Dakota. I spent over $500 on a broken wire!!