Comanche won't start....no fuel.

[Disturbed]

OK I have been working on this truck for the past five months, finally took it off the lift, I put it up on the lift the week before Thanksgiving.

 

Tried to start it and it won't start. I didnt have alot of time to do trouble shooting but here is where I stand. It isnt getting fuel. The fuel tank, fuel lines and fuel filter are new. The pump isn't new but was functioning fine when I pull the truck into the shop.

 

I can hear the fuel pump run. If I turn the key on and off a few times you can hear it get to the point where it sounds like the fuel system is primed (pump doesnt run as long).

 

There is 5 gallons of fuel in the tank so I know it isnt just out. I hooked up a fuel pressure gauge to the fuel rail at the pressure port and there is no pressure. Just before I called it quits I did notice that the vacum line going to the fuel pressur regulator (on the end of the fuel rail) is broken. Would this cause a no fuel issue? I tried cranking while pressing the purge button on my fuel gauge and got no fuel.

 

I am going to pull a line off the fuel pump to see if it is pulling fuel from the tank, but I think it is because of the way it reacts when priming the fuel system. Does anone have any ideas? I really want this truck driving by the end of the weekend. Thanks for any help.

[Disturbed]

Also forgot to mention that the fuel strainer on the fuel pump is new.

[Geonovast]

Was the pump ever taken off the sender? When I replaced the pump in my 2.5, the new pump had the terminals switched from the original pump, and nothing was labeled, so the damn thing was spinning backwards on me.

[Disturbed]

Was the pump ever taken off the sender? When I replaced the pump in my 2.5, the new pump had the terminals switched from the original pump, and nothing was labeled, so the damn thing was spinning backwards on me.

 

Yes the pump was removed from the sender. The terminals were spade terminals and they were different sizes so there is no way, that I know off, that I could have switched them. I guess I can verify this if I pull the rubber line off the fuel pump at the tank and see if I am geeting fuel there.

[Geonovast]

Another possibility..

 

Could you have maybe switched the fuel return and supply lines?

[Disturbed]

Another possibility..

 

Could you have maybe switched the fuel return and supply lines?

 

 

 

Maybe, this truck was apart for months, I thought I hooked everything back up correctly but I could be wrong. I can answer this question by doing the same test I mentioned above.

[BORDENCOMANCHE]

I pulled my entire pump out without using anything other than a flat head screw driver and a hammer in my drive way, drive shaft on. For the future guys, get a set of grease pencils from your local Staples and colour code everything you disconnect.

 

Hope this helps for the future.

[Wildman]

Pull the in-put line from the frame filter, and see if your getting fuel out of the tank first.

 

If you have fuel, it could be the frame filter, or the supply line up to the fuel rail pinched/plugged.

 

If there is no fuel from the tank, then you'll need to pull the sending unit and check the pump, and the small soft line from the pump to the sending unit head.........and as in the pass......make sure the worm clamps are on that line.

 

Having the vacuum line off the pressure regulator, would cause the fuel rail to reach 39psi, instead of the 31psi you should have.

 

Also.......is the gas fresh???? and Not 6 month old varnish????

[Disturbed]

Pull the in-put line from the frame filter, and see if your getting fuel out of the tank first.

 

If you have fuel, it could be the frame filter, or the supply line up to the fuel rail pinched/plugged.

 

If there is no fuel from the tank, then you'll need to pull the sending unit and check the pump, and the small soft line from the pump to the sending unit head.........and as in the pass......make sure the worm clamps are on that line.

 

Having the vacuum line off the pressure regulator, would cause the fuel rail to reach 39psi, instead of the 31psi you should have.

 

Also.......is the gas fresh???? and Not 6 month old varnish????

 

The tank is new, the gas is new, the strainer is new, the flexible lines from the tank are new, and the fuel filter is new. I put worm clamps on all the lines inside the tank when I put it back together. I will pull the line on the fuel filter tomorrow, that was my plan, and see what happens. All things considered I am hoping I was a moron and hooked the lines up backwards.

[Wildman]

Well.......ya didn't post that every thing was new :hmm:

 

Yea, that's possible, but unlikely........

 

The supply line is larger that the return line. They could be crossed at some point.

 

Or, even thought the terminals on the pump are different, you still could have reversed polarity :dunno:

[Disturbed]

Well.......ya didn't post that every thing was new :hmm:

 

Yea, that's possible, but unlikely........

 

The supply line is larger that the return line. They could be crossed at some point.

 

Or, even thought the terminals on the pump are different, you still could have reversed polarity :dunno:

 

I actual did mention that some of the parts were new, I didn't go into quite everything BUT I really don't have much faith in new parts anymore, I have had more than my share of parts new out of the box that were bad from parts stores, so I have quit thinking just because itis new it is good.

 

If I remember correctly the spade terminals were different enough in size that I could have put the big connector on the small terminal but not the other way around.

 

I had the lines marked but then ended up changing out the flex lines so maybe I mixed up the tags I had on the lines when I put the new lines on. Hopefully I can put the thing back up on the rack today and see what is going on.

[CWLONGSHOT]

Just throwing this out there... Disturbed is spot on, "NEW" doesn't immediately remove all doubt to the functionality of a given part.

 

I agree, it should, but sadly, it doesn't...

 

My first thought was the ground, but you say that you can hear the pump prime. I didnt catch the year, but is the ceramic resister good?

 

then I thought of the filter. You say new, did you check to see the fuel flows that far?

 

CW

[Wildman]

Yes, New parts are a hit and miss in some cases.........or they don't last 20 years and 200K like the OEM part :headpop:

 

So, it you got it on the lift today.........let us know what ya found

 

:popcorn:

[Disturbed]

The truck is running but I can't tell you what was wrong with it. I pulled the flexible lines coming out of the tank and got no fuel. Pulled the pump and submersed it a buckets of gas, put 12volts to the pump, it ran but I got no fuel. Reversed the polarity, again it ran but I got no fuel. Removed the strainer, now I got fuel, reinstalled the strainer, now I am getting fuel. The strainer is new so it is not gummed up. Put the pump back in the tank, cycled the key, now I have fuel pressure on the fuel pressure gauge. Cranked it over, and it fired right up. 39 psi at the rail which is right since the vacum line is broken that provides vacum to the pressure regulator. Wish I knew what was wrong but at least it is running. :dunno:

 

I have to fix the vacum line, torque the lug nuts, tighten the rear DS bolts, fix a bad ground in the front turn signal, and empty out the bed. I should be able to it inspected and be driving it by the weekend. I hope to be able to drive it to the RC Rocs comp at Rausch Creek on Saturday. Look for the blue short bed that is lifted 4" on 31s.

 

Thanks for everyone help. Now that this project is done I can get my CNC Plasma table set up and start cutting parts. If you are going to be at Rausch on Saturday look me up. I will probably be hanging out with Randy Wood from Adventurous 4x4. He will have a tent set up there. My name is Kris.

[1tonMJ]

Just wondering if you ever figured the problem out? Seems like such a simple cause to the problem. The answer seems to elude you. Best of luck, Mate. :smart:

[CWLONGSHOT]

Good show Kris!!

 

I'm thinking it was air bound... SHOULD be self priming and shouldn't happen... but I think it did....

 

CW

[Disturbed]

Just wondering if you ever figured the problem out? Seems like such a simple cause to the problem. The answer seems to elude you. Best of luck, Mate. :smart:

 

No, I never figured out what was wrong. I don't like fixes like this, the no fix fix, because if it comes up again I don't know what to do to fix it except what I did before. But since it is now working I can't really diagnos the problem.

 

I can't wait to drive this truck. I bought it the weekend before Thanksgiving (yep, November 2009) and what I was told was wrong with it should have taken a few weekends to fix. Needless to say most of what I had to do not mentioned by the PO. The good news is I am now very confident that the truck is in good shape. The only thing that I am not 100% sure about is the Renix EFI. But I have a 4.0 with Mopar EFI on it, an ECU, and a wiring harness sitting in my shop with no real plans for it, so if the Renix becomes too much of a hassle I will just do a little swapping.