Jeepin'_Aint_EZ

^^^ hit the dash or what I do and push the button for the trip reset when the gauges act up

CCKen

Hitting the dash sometimes reseats the cluster pins in their pin cavities. Normally if things return to normal, there is a problem with the connections.

Pushing the Odometer trip reset button has no bearing.

BlueRidgeMark

Replace all that assuming with some thinking about cause and effect, and some question asking, and you'll be a lot better off.


Fuel pumps don't cause lights to flicker and tachs to go to zero.

DeJay126

I noticed this time that the speedometer also drops to zero, although not every time the tach does. It drops to zero about every other time. So yeah, it's definitely not the fuel pump causing it. I tried scanning for codes and didn't get any codes. I'm so Damon confused and i just want my car to run.

CCKen

First, it looks like you just replaced the pump and not the fuel pump module assembly - correct? If so, the fuel pressure regulator wasn't replaced - correct? If so, did you check the fuel pressure at the fuel rail after you replaced the pump? Remember you had 10 psi before.


The Part Time light on the instrument cluster has 12 volts to it and the light is looking for a ground to illuminate the bulb. The Mode Switch on top of the TC provides the ground when in Part Time. It looks like the Mode Switch is bad (damaged?) or the wiring to it has been chafed and is shorting to ground intermittently. Climb under the Jeep and examine the wiring going to the Mode Switch and the Vehicle Speed Sensor. Also, examine the downstream O2S wiring while you're there.


The TC Mode Switch is grounded at G101 (stud at one of the coil mount studs). So is the TCM and PCM grounded there. See pic. Examine the wiring at the coil mount studs.


It would appear as though some wiring or a sensor was damaged from rocking the Jeep back and forth getting it out of the mud, or mud/water has entered a sensor/module electrical connector. You need to really look closely at all engine sensors and wiring and all wiring under the Jeep for damage.

DeJay126

So, basically what you're saying is it could be something as simple as some dirt in a connection causing it to not have proper connection.

I don't have a fuel pressure gauge to check the pressure again, I need to get one from someone or see if any stores will let me rent one.

I'm hoping that you're right and maybe just a good cleaning of all electrical components will solve the problem.

As far as then question about the pump, yes I only replaced the pump. What module are you talking about?

CCKen

The Module is the entire fuel pump assembly as shown in the pic below. The fuel Pressure Regulator/Filter Assembly plugs in to the top of the Module and is part of the Module. See pic below.


As far as connectors goes, yes it could be a connector, but it could also be damaged wiring. You should check everything in the engine bay and under the Jeep.


Fuel Pump Module Assembly:





Fuel Pressure Regulator/Filter Assembly (the filter is inside):

Cane

people have mentionned the cps a couple times and I don't see you addressing it. did you replace it? if not go ahead and try that, crank-no start sounds a lot like a cps to me also. if you do replace it, go with mopar and not aftermarket. it's worth the extra bucks

BlueRidgeMark

+1.

I just had a cam sensor fail after 9 months. It was not Mopar, but it came with a new distributor put in by the dealer. Cost me $50 in labor to have them replace it under warranty.

Do not buy cheap fuel pumps or sensors. You will pay more in pain and money.

And a fuel sending unit is still not going to make your tach go crazy.

DeJay126

I haven't replaced the cps yet, that will be then next issue I address. that stands for cam position sensor, right? what exactly does that do, and I'm guessing it's going to be an expensive part

lol

BlueRidgeMark

It's either the Cam Position Sensor or the Crankshaft Position Sensor. Same abbreviation for both, which is confusing. I have seen some places where CkPS is used for the CranK sensor to avoid confusion. Seems like a good practice to me.

Having just priced them, I can tell you the Cam sensor is going to run in the $150 neighborhood from the dealer.

Cane may have been referring to the CkPS, which is a common suspect for a no-start, no-spark condition. I don't remember the cost on those, but it's easy to look up online.

On the other hand, the cam sensor can ALSO give you a no-start, no-spark condition.

DeJay126

Does anybody have an exolanation as to why the tach drops to zero while the problem occurs? Is this common with the CPS going bad?

I'm going to attempt to drive it - back to my house and go over all of the wiring harnesses and see if one came loose or has dirt in the contacts and then I'm going to purchase the CPS.

Jeepin'_Aint_EZ

For some reason mine likes the trip reset button pushed lol. I know, I know, weird. But I've had more luck just pushing on the button (firmly) and it must be putting pressure in the right spot to reseat the pins. It's actually been quite a long time since I've seen the ol "check gauges" light turn on.

DeJay126

So, here's an update. I replaced the throttle position sensor. Since replacing it, when the Jeep stalls it will now start back up instead of sitting there dead. I guess that's progress?

Well, I broke down about an hour ago and ended up outside of a mechanics house. He had a fuel pressure gauge and I checked the fuel pressure. While cranking it was at 10 and when I turned the key off it jumped to 19.

Considering I replaced the fuel pump first, I'm not real sure what to do. I'm going to hope that Advanced Auto is cool and honors their lifetime warranty. Anybody have any clue?

CCKen

Looks like the fuel pressure regulator/filter assembly should have been changed as well. This is why most folks change the fuel pump module assembly as opposed to just changing the pump. The pump you installed is probably doing its job but the regulator is defective.


Down comes the fuel tank again.