Hi my name is Maurice

little history:
i bought my first Dodge 2 weeks ago and it was a SX2.0 Sport
clean , no engine light , couple things changed and 151k from the first owner.
everything worked flawlessly, i taught i had good deal for 1600$....

Anyhow..
yesterday i went in the garage to start the car and nothing...
the car cranked but woudnt start , just like that , out of no-where , no signs ,nada.

so i started diagnose ,
i started to check if the timing belt broke,that was ok.
then i check for spark , that was ok

**then i check for fuel , BAM ! no fuel coming out of the fuel rail while putting the key to on/off/on/off/on/off

So my buddy went underneath the car by the fuel pump , and we repeated the on/off procedure. my buddy couldn't hear the fuel pump.

so we figure the fuel pump was bad, so I changed the fuel pump.

Here is where it gets a bit crazy....

new pump in,try to start the car , same problem car cranks but wont start.

So we check if there was fuel coming out of the rail again, nothing.
So we checked if the fuel pump was making noise while turning the key to on, nothing.
So we hooked up a spare battery directly to the pump, the car started right away ! yay !
So we checked if they is power to connector , it says 11.8V

but when i connected them together , nothing works
we tried connecting direct ground to the fuel pump,nothing.

we are running out of ideas here, i suspect the harness my be the culprit.
but im a total noob with dodge , i did as much as i could, but im running out of ideas.

any input would be appreciated ! im so sad ! HELP !!! please .

Maurice.

 

if it started when you first got it i would rule out the harness,i would look at the relays under the hood may be a bad one.

 

Welcome to the 2nd Gen Neon forum.

Good trouble shooting feedback, too bad you didn't do the listen test Before replacing the fuel pump. Keep the old one as a spare, it's likely ok.

^+1 on checking/thumping/wiggling the fuel pump power relay in the under hood power distribution box. Also fuse #21 a 20amp.
Power relays are a common problem part, so try swapping out the fuel pump power relay for a Like one not needed to run the engine, like the A/C power relay. Sometimes the power relay contacts go high resistance & drop voltage under load & cause mischief.

Remove & check the relay & fuse socket/pin contacts for corrosion, bent pins, spread sockets, as with 11.8 volts it seems you have a B+ voltage drop at the fuel pump electrical connector.

Go here & scroll down to find the fuel pump wiring pictorial. http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=78943

Operating the pump with the battery & having the engine run, says the ASD relay is ok & fuel pump is ok but the 12 volt feed, & or the pump ground may be faulty/high resistance, such that when the pump is plugged in, it's load causes the 11.8 volts to drop so low it won't run.

If you have a ELM scan tool, hook it up & have it scan for trouble code clues & post All code Numbers, as they can help focus a trouble shoot.

More thoughts for consideration, let us know how the trouble shoot goes.

 

First thank you for reading this/helping me

I try to start the car this morning and it started quite easely.
it stayed few second idling but it was rushing,and it died almost immediatly.
i did it couple times and it dies faster everytime , but unlike yesterday it fires right up,it just dies right after.
pretty sure because I primed the system while putting power to the pump yesterday.

PawPaw its like the PCM is not sending ground to the pump under load. actually it cant even primed the system.

Also no blown fuse, one fuse didnt light up with the test light tho,fog lights.
they never worked, but i dont think thats relevant.
So no blown fuse in interior panel or engine bay fuse box.

i did notice a custom relay that was made by the old owner that connects the starter and coil pack, i checked it , clicking is good and no resistance.

So i decided to check more the fuel pump relay:

Current Car Voltage 12,4 Volt
i lose 0.5 volt to pin 86 which brings it to 11.9V (not sure if its relevant)
all the other is a 0.2 voltage drop.
i jumped pin 87 to 30 , same thing , carstarts but dies right after.

i was thinking of performing a fuel-pump re-wiring like on this website:
http://www.enginebasics.com/Advanced...p%20relay.html

I also bought this :
https://www.modernperformance.com/pr...-4-fuel-system

if all that doesnt work , i will be suspecting the PCM.

let me know what you guys think.
much apreciate the help, thanks again.

Maurice.

 

12.4 volts open circuit/no load, suggests the battery is only at about 75% soc. So maybe consider using your smart battery charger to put it on a slow rate of charge of say 4-6 amps overnight to top it up.

Looking at the wiring pictorial in the link I posted above, it doesn't show the computer switching the fuel pump ground.

Again, seeing as how you only had 11.9 volts open circuit/no load, at the fuel pump & it not running when you plug it in, it suggests you may have a high resistance B+ feed to the fuel pump.
Again, the fuel pump power relay contacts are a known problem in these kinds of no run woes, so swap the fuel pump power relay with a like known good one not needed to run the engine & let us know how it goes.

If the engine runs with the 12 volt source you wired to the pump, then the computer is ok, but imo the under load B+ feed to the pump, or it's ground connection sure belongs on your suspect list right now. So begin by swapping out the fuel pump power relay & if no joy, consider beginning a under load voltage drop test starting at the fuel pump power relay & work your way toward the fuel pump then to it's ground point.

When you ran the fuel pump with the external 12 volt source, if you provided both B+ & B- connections from the source Directly to the pump, to successfully have it run the engine, also put the fuel pump Ground connection & wiring on the suspect list.

If when you measured the unloaded 11.9 B+ volts at the pump, if you measured it across the pump electrical connector, using the pump ground lead, rather than a good clean unpainted chassis/body ground connection, count that as another reason to suspect a fuel pump ground problem.

The inexpensive ELM scan tool can query All of the vehicle computer/controllers for trouble code clues, that can help focus a trouble shoot, but if you don't have, or can't come by one, continue with the multi-meter Under Load voltage drop tests.

More thoughts for consideration, let us know how it goes.

 

little updates:

thank you PawPaw for the suggestions.
i did swap the relays multiple times already , i just didnt mention it.
i wish it was that easy.

i received the harness from ModernPerformance , quality is good.
its basecally a harness with

-2 fuel pump connector
-1 relay ,
-30amp in-line fuse ,
-Ground wire
-Positive wire that is hooked to the alternator post.

i installed the harness , made sure i had good ground contact,
checked the fuses , checked the relays , nothing.
No fuel in the fuel rail .

Just to be sure , I also got myself a new battery , even if that one was only 1,5years old by the sticker.

And I also got myseld a ELM327 reader like suggested.
im using it with the DashCommand app ,its pretty self-intuitive and im actually impressed for what i paid , its totally worth its money.

Anyhow, no active MIL light or stored ones.
Evertyhing seems alright. Im not expert on the case but if you want more info from the scanner just let me know what you need.

im really running out of ideas now.
this new harness is giving power to the fuel pump right away from the battery.....why woudnlt work.

help please!!

 

Ok good feedback. Lets think about this some more. If the fuel pump is now running, but no fuel is making it to the fuel rail, something is amiss with delivery. Like a clogged fuel pump filter, or kinked line, or faulty fuel pump.

Did this problem by chance begin after some "event", like filling up at a out of the way gas station you don't usually use, or was a tanker there filling the under ground tanks?
Have you hit, or drug on ice or snow, or had the vehicle sitting in below freezing temps where any water in the tank or lines could freeze & block flow?

 

To resume

i bought the car 3weeks ago, did a oil change the second day i bought it.
Drove it for about 200 maybe 250km's.
once on the highway at 110km/h(65mph) for 20min (10min each way).
Rest of the time was little things like grocery or store.

The car is kept in a heated garage at 10celsius (50 Fahrenheit).
I only parked outside once because it was over freezing temperature.
The car was running A1 /Excellent.

I forgot to mention that 2days ago i tried unhooking the fuel line to see if there was pressure & there was definitly fuel pressure,it was pissing everywhere. so i went back in the car to start it but it died right away , faster each times , to the point where there is not enough fuel to start the car.
checked the line again,dry.....

*i really wonder how come it had pressure, the only time it had pressure was when i hooked up the pump directly to a spare battery.

i rechecked the voltage
at the fuel pump relay , its normal 12.8
at the pump connector and this time it was at 9volt (~3volt) drop.

i have a huge voltage drain from the fuel pump relay to the fuel pump connector.

i was under there installing the harness and i inspected the fuel line,they are fine.
i taught the fuel filter was integrated to the fuel pump assembly, is there another fuel filter ? even so i dont think its the culprit.

anyhow
I decide to install a toggle switch , that hooked the battery to the fuel pump connector directly , BAM , it worked !!! i was able to go around for a drive.

its pretty ****ty that i have to turn on a switch before driving it and turn it off when shutting the car off, but for now at least i can get to work till i get her figure out.


I have some stupid question....

is it possible that the PCM in not engaging the relay under load ?

would other things that the PCM controls be wrong if it was malfunctionning ?

is this a symptome of a bad PCM ?

is it bad to have the fuel pump hook straight to the battery via toggle switch with a 30amp fuse?

sorry for the noob question.
thanks again,very apreciate the help

 

We have a "return-less" fuel system.
The fuel pressure regulator is integral with the in-tank fuel pump assy.

At KOEO, the computer commands the fuel pump power relay on for about 1 second to run the fuel pump & prime/pressurize the system for the upcoming engine crank for a start.

When the ignition switch is turned to "Start" to crank the engine, current flows to the starter power relay solenoid winding to cause it to close it's contacts, which then sends power to the starter solenoid winding that's integral with the starter motor. The starter solenoid pulls in to engage the Bendix with the flywheel & close the high current starter motor electrical contacts to run the starter motor & crank the engine for a start.

When the starter power relay gets it's ignition switch start power signal, the computer also gets power from this connection, to wake it up, that we're about to crank the engine for a start, so the computer begins looking for a CKP sensor signal that tells it the crankshaft is turning, so the CKP signal triggers spark & turns on a transistor in the computer to do it's thing & turn the fuel pump power relay on again, to restart & keep the fuel pump running & to ground switch the fuel injectors, timed by the cam/CMP sensor PID, so they'll squirt the right amount of fuel at the right time, to start & keep the engine running.

SO, for a start & continue to run scenario to happen, the computer run transistor needs those two inputs to restart & keep the fuel pump going. (The ignition switch start current signal & the (CKP), crankshaft sensor (PID) output signal).

Once the engine is cranking, the computer looks for a crank shaft sensor (CKP) PID signal so it knows the engine is turning, so the computer run transistor keeps the fuel pump power relay solenoid energized, to keep it's power contacts closed to run the fuel pump.

On 2001 & later models the fuel pressure should be 54-64 psi, (delivery rate is about 1/2pt-15 seconds pump run time) controlled by a fuel pump assembly located fuel pressure regulator relief/dump valve, that keeps the fuel rail pressurized between 54-64 psi. When fuel pressure exceeds the max value, the pressure relief valve opens to limit line pressure & returns the excess fuel back to the tank. Once pressure drops below it's setting, the dump valve closes & the pump builds pressure again & the scenario repeats as long as the engine runs.
So, once the engine is running, so is the fuel pump. The pump is immersed in fuel to keep it cool & lubricated. This is why it's a good idea for us to keep 1/4 tank of fuel, so to keep the fuel pump covered, cool & happy. In hot weather it's a kind thing for us to do for that puppy.

9 volts to the fuel pump under load is a serious voltage drop & needs to be put right without delay, as the fuel pump & it's electrical delivery circuit are having to handle a lot of extra current flow the voltage drop is causing. The extra current draw will make them run Hotter than designed for. So finding & fixing the under load voltage drop root cause, will likely put your problem right.

EDIT: SO, on the voltage drop between the fuel pump power relay & fuel pump electrical connector, look for fuel pump power relay internal contact resistance, relay plug in socket corrosion, loose/spread relay distribution box socket connections, faulty wire crimps, damaged wire run/broken wire strands, loose inline electrical connector, bent pins/spread sockets, or corrosion on the pump wiring run socket connections. Try a wiggle test on the wiring. Swap the fuel pump power relay for a like known good one, not needed to run the engine. Whew!!!! lol
A bunch more thoughts for consideration, let us know what you find.

 

Hey guys , im back with my car 30 clicks later , she's been good to me , im happy .

so last time I was here I installed a toggle switch between the fuel pump and the battery .

Haha couple people taught I had Nitrous because of the red switch 😂.
To be honest I was getting sick of turning off/on the switch , plus if I would forgot , the car would be dead in lile 5hrs..

Anyways , I decided to tackle the problem again this week ,

soooo
i checked the voltage at the fuel pump again , it REALLY got worse 1.10 Volt !! (Green w/ white stripe)

we decided to remove the rear seats behind the driver seat and check the voltage there, same 1.1 V.

We removed the fuseblock in the engine bay and decided to run another wire from the fuel pump directly to the relay.

BAM ! It worked !!!!

So no more toggle switch , finally !
Its cool at first but it really gets annoying.

i suspect the problem is between the fuel pump relay and the fuel pump (green and white wire).

thank everyone for helping 👍👍👍