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No Start after a year off

EMSJEEP

NAXJA Forum User
Location
Long Island
Ugh, so the 2001 came off the road for a while as it got retired from DD. The gas in the tank turned and I didn't start it for a year because of that.

I dropped the tank and noticed a mouse nest around the fuel pump. They started to eat the insulation, I rewrapped everything there. Poured out 10 gallons of brown gas, refilled with premium, stabilizer and MMO. Pulled the plugs, MMO in the cylinders before cranking. Now, nothing. Cranks fine, fuel level is giving wonky readings. The pressure purge in the fuel rail drains good gas, so it appears to be pushing fuel in. Plugs looked ok when I pulled them. Only hint is an intermittent P0340. Fuses look ok.

Where do I start? Thanks!
 
air, fuel, compression, spark

have you tested fuel pressure with a gauge?

have you tested spark?

Almost noting in the way of specialized tools out here in the middle of nowhere where I parked the thing. If I can't figure it out this week, I'll start getting involved next week.

I'll pull the rail tomorrow and verify spark.
 
Autozone will rent/loan a fuel pressure tester for $150. Harbor Fright sells them for $20. Don't know if either of those are options for you.

Advance sells a Lisle inline spark tester for $15ish that's pretty good.
 
Autozone will rent/loan a fuel pressure tester for $150. Harbor Fright sells them for $20. Don't know if either of those are options for you.

Advance sells a Lisle inline spark tester for $15ish that's pretty good.

I've got an ACE hardware, a bait shop and a ratchet set. That's about the extent of it.
 
So, with the distributor rail off and a plug stuck into it, I see no spark while cranking.

Gonna go find the CPS and see what I can see.
 
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So, with the distributor rail off and a plug stuck into it, I see no spark while cranking.

Gonna go find the CPS and see what I can see.

Use a vacuum hose in your ear to listen to the injectors while cranking. Crank and Cam sensors (and ASD relay and the ECU) control timing for spark and injectors both, if you have one or the other then they are good.
 
Since it's been sitting so long, try unplugging the CPS connector in the engine bay, clean it up, and try it again. Maybe you'll get lucky.

I can't find the darn thing. This is an 01 with the pre cats and there is an O2 sensor connector where the CPS is supposed to be. Internet has been less than helpful in locating so far. Found one diagram that suggests it is passenger side on the engine? Dunno.

It has a permanent CPS code now.
 
So CPS plug sits below the vehicle next to one of the O2 sensor plugs rear and down from the sensor itself. Plug looked clean. Unplugged and plugged back in a few times. Code returned with each crank. Think I'm going to come back next week with a new sensor and the rest of the necessary tools.
 
Replaced CPS, no change. Picked up the fuel line disconnect tool. There is no gas in the lines, no less pressure. Pulled the fuel line apart at the first connection from the pump, bone dry. The gauge isn't doing wacky stuff anymore, just flat empty after adding 10 gallons.

Guessing fuel pump? The mice chewed the insulation off the lead wires from the pump, but they are still intact. All fuses look good.
 
Do you hear the pump run for a second or so when you turn the key to ON? Also, could the relay for the pump have gotten stuck/failed?

If you can work out which wire is which, try running 12V straight to the pump and see if it runs at all. If it runs, you can start working your way back along the wiring to the relay.
 
Do you hear the pump run for a second or so when you turn the key to ON? Also, could the relay for the pump have gotten stuck/failed?

If you can work out which wire is which, try running 12V straight to the pump and see if it runs at all. If it runs, you can start working your way back along the wiring to the relay.

When you say "on" you mean the position before cranking, correct? I'll be searching for a diagram....it's 4 pins
 
Yep, last position before crank.
 
So no noise from the pump when turned to "On" however, when in "On" I have constant 12v to one pin, assuming this is power to sending unit, and a 2 second 12v spike to another pin, guessing this is power to pump to prime. So, either the pump spontaneously died (would sitting in bad gas do that?) or the wiring was more chewed than I thought. Why would sending unit and pump die simultaneously if not the wiring I guess...

Anyway, if I'm taking the tank down yet again, I'm going to have a pump on hand. So question now is, what's the story on aftermarket vs MOPAR? Quadratic has the Crown part on sale status right now.
 
Looking at the 2000 FSM, not sure but it looks like Dark Green w/ White stripe is power from the relay, Brown w/ Yellow stripe is sensor ground (pre resistor), and Dark Blue w/ Light Green is sender output (post resistor). Probably a black wire on the pump that grounds to the tank.

2000_fuel_pump_module_conn.png


Have you tried jumping the relay in the PDC? or measuring it with voltmeter would be better if you have a potential short
 
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Looking at the 2000 FSM, not sure but it looks like Dark Green w/ White stripe is power from the relay, Brown w/ Yellow stripe is sensor ground (pre resistor), and Dark Blue w/ Light Green is sender output (post resistor). Probably a black wire on the pump that grounds to the tank.

2000_fuel_pump_module_conn.png


Have you tried jumping the relay in the PDC? or measuring it with voltmeter would be better if you have a potential short

So it looks like I have appropriate power at the harness side connection to the pump, no?

One of the four pins at the pump/harness connection is solid black and worked as a ground. I guess I could jump the pump from a battery if maybe the 11.8 volts is insufficient?
 
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^^ thats assuming you have solid wiring at the tank/sender.

I think chewed wiring is the culprit to both
 
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