Truck dying- fuel pump? Please help :)
#22
I had the exact same problem with my 99 2500 5.9L 360 government truck from AZ too... thats really weird... anyways, i swapped out the fuel pump and it did no good. it was a clogged cat. to swap out the fuel pump/regulator/filter/float assembly, it will cost you around $250 at autozone for the complete setup. its stupid that you have to buy the whole assembly and not individual parts (unless i'm wrong then someone correct me PLEASE). just unbolt the bed and place blocks of wood between the frame and bed bottom to prop it out of the way then just get in there, unplug the connectors and hose, unscrew the plastic ring around the pump assembly, take it out, put the new one in, have fun with the PITA plastic ring that holds the assembly to the tank cause its a bitch to get back on, then reconnect the hose and connectors, bolt the bed back on, and go! the easiest way to check the cat is to take out the O2 sensor and start the truck, or what i did was unbolt the exhaust at the flanges to let out the maximum exhaust to make SURE the cat was the problem. if it is your cat, just get a sawzall or hacksaw and cut that sucker off, break all of the honeycomb out with a piece of pipe, then weld it back in place (unless you have emissions control, then you have to get a new cat).
#23
You can't go by O2 voltage at WOT to determine anything as far as fuel is related. At WOT the PCM ignores O2 voltage and the narrowband sensors our trucks use go from .5 volts to 5volts but only measure A/F ratios somewhere between 12 and 16.
I have heard that Airtex is not the greatest brand and that a Delphi pump is of much better quality. I have not had to replace one yet, but several mechanic friends of mine have told me that the earliest they've seen problems with the Dodge pump is about 130K. The Chevy pumps are an entirely different matter.
Do you have a schrader valve on the fuel rail? You can test the pressure at the rail and it should be 49psi +/-5psi according to the FSM.
I have heard that Airtex is not the greatest brand and that a Delphi pump is of much better quality. I have not had to replace one yet, but several mechanic friends of mine have told me that the earliest they've seen problems with the Dodge pump is about 130K. The Chevy pumps are an entirely different matter.
Do you have a schrader valve on the fuel rail? You can test the pressure at the rail and it should be 49psi +/-5psi according to the FSM.
#24
I had the exact same problem with my 99 2500 5.9L 360 government truck from AZ too... thats really weird... anyways, i swapped out the fuel pump and it did no good. it was a clogged cat. to swap out the fuel pump/regulator/filter/float assembly, it will cost you around $250 at autozone for the complete setup. its stupid that you have to buy the whole assembly and not individual parts (unless i'm wrong then someone correct me PLEASE). just unbolt the bed and place blocks of wood between the frame and bed bottom to prop it out of the way then just get in there, unplug the connectors and hose, unscrew the plastic ring around the pump assembly, take it out, put the new one in, have fun with the PITA plastic ring that holds the assembly to the tank cause its a bitch to get back on, then reconnect the hose and connectors, bolt the bed back on, and go! the easiest way to check the cat is to take out the O2 sensor and start the truck, or what i did was unbolt the exhaust at the flanges to let out the maximum exhaust to make SURE the cat was the problem. if it is your cat, just get a sawzall or hacksaw and cut that sucker off, break all of the honeycomb out with a piece of pipe, then weld it back in place (unless you have emissions control, then you have to get a new cat).
The regulator is sold separately, but parts stores normally don't have them on hand. The "fine" filter is embedded in the regulator. There is a "coarse" sediment filter on the end of the pump's pickup. Autozone didn't even show one, but NAPA and O'Reilly's did.
#25
The issue, though, is it's not getting back into open loop when I floor it, as it runs out of fuel (it seems) well before that.
Tried running with the oxygen sensor out- no change in how it drives. The metal area around the sensor inlet is red, by the way- rather bright. It's just past a rust color, I'd say. To clarify, I do not mean reddish, I mean RED. Burnt siena, dark rust red.
Also, with a catalytic converter, until it's completely clogged, performance would have degraded. Every time I've seen one clog up, it always starts to sputter when the truck/car is hot, then after sitting a while, cools down and runs decent for a little while. This ran like poop from cold start on. Won't hardly get above 30 MPH up a SLIGHT hill.
My theory is that the pump is dying due to the extra load placed on it by the suddenly increased performance (not huge, but relatively a big change) by the new parts, most notably the added fuel needs due to the extra air pulled in by the intake. My other problem is the nearest auto parts/tools places that are open on the weekend is about an hour away (hooray for the boonies), so I am trying to make it all in one trip.
I'll check for a Schrader valve on the rail when I go out next- Mark W.
Tried running with the oxygen sensor out- no change in how it drives. The metal area around the sensor inlet is red, by the way- rather bright. It's just past a rust color, I'd say. To clarify, I do not mean reddish, I mean RED. Burnt siena, dark rust red.
Also, with a catalytic converter, until it's completely clogged, performance would have degraded. Every time I've seen one clog up, it always starts to sputter when the truck/car is hot, then after sitting a while, cools down and runs decent for a little while. This ran like poop from cold start on. Won't hardly get above 30 MPH up a SLIGHT hill.
My theory is that the pump is dying due to the extra load placed on it by the suddenly increased performance (not huge, but relatively a big change) by the new parts, most notably the added fuel needs due to the extra air pulled in by the intake. My other problem is the nearest auto parts/tools places that are open on the weekend is about an hour away (hooray for the boonies), so I am trying to make it all in one trip.
I'll check for a Schrader valve on the rail when I go out next- Mark W.
Last edited by thaduke2003; 02-21-2009 at 02:44 PM.
#26
can I have you check something? It's a longshot, but it sound similar to what I did once. Do did say you were fixing the intake right?
I had a problem like you're describing and I recall that the throttle linkage that is on the side of the TB (the one of 3 linkages that connects from the front of the engine,) runs under a spacer. I took my throttle linkage off and when I reconnected it, I didn't run the cable under the spacer and the truck wouldn't rev up and used a lot of pedal to even get going. Check to make sure that cable is run under the spacer. It's on the passenger side under the airhat that comes in front the front side of the vehicle.
I had a problem like you're describing and I recall that the throttle linkage that is on the side of the TB (the one of 3 linkages that connects from the front of the engine,) runs under a spacer. I took my throttle linkage off and when I reconnected it, I didn't run the cable under the spacer and the truck wouldn't rev up and used a lot of pedal to even get going. Check to make sure that cable is run under the spacer. It's on the passenger side under the airhat that comes in front the front side of the vehicle.
#27
I didn't remove the cable when I did the intake.
Next up, is there a trick to putting the locknut (big plastic ring) back on? I'm having a devil of a time getting it back on there. Patience being the one thing I lack, figured I'd ask you guys- see if there's an easy way.
Tested the pump- flow rate should be measured in DPH- Drops Per Hour. Lots of AZ dirt and crap in the filter, all over the housing, and in the bottom of the tank. Spent all morning cleaning that sucker out!
Thanks, Mark W.
Next up, is there a trick to putting the locknut (big plastic ring) back on? I'm having a devil of a time getting it back on there. Patience being the one thing I lack, figured I'd ask you guys- see if there's an easy way.
Tested the pump- flow rate should be measured in DPH- Drops Per Hour. Lots of AZ dirt and crap in the filter, all over the housing, and in the bottom of the tank. Spent all morning cleaning that sucker out!
Thanks, Mark W.
#28
The easiest way that i found for getting the ring back on the fuel tank is to spin it so that it starts to catch on one side, then hammer the crap out of the other side with a rubber mallet and a thick bladed screwdriver or something that isnt very sharp. this will snap the ring over the threads and from there you should be able to screw it all the way on. sounds stupid, i know, but i'm not kidding. i did this. i would advise running a bead of silicone around the ring and the pump just to keep sediment from getting in there if you do a lot of off-roading.