Fuel Supply Problem

[Morphious]

Had a problem with the dog today, can't quite explain what was the cause, at first thought that the mallory had gone out, but after limping back home and doing some checking, don't think it was the problem. Here is what happened. Driving in town, the truck starts stubling and dies, get it running again by double clutching it. Got pulled over to the side of the road and noticed that I didn't have any fuel pressure during this. I have about 60k or more miles on the mallory. I killed the truck once I got it pulled over and did a quick check of things, all seemed to be ok on looking it over. I started the truck back up and had fuel pressure so I headed to the house. Got to the house and unhooked the fuel line at the filter and turned the pump onto prime, got it to prime once, but that was all. I wired the pump to run off the stock power for the old stock fuel pump. I then ran wires from the battery to power the pump and I pumped about 2 gallons out of the tank, worked like a charm. I am wondering if the power coming from the ecm might be what is failing me. Has anyone else had similar problems?



Morph.

 

[Bigsaint]

Morph, my guess would still be with the Mallory as I had inconsistent readings for about one week before it completely died. Might be a good time to pull the pump and clean the gerator, etc. Real easy job to do, once the pump is off the frame. Actually, you could remove the gerator assembly from the pump while it's still mounted, just remove the two screws on the bottom of the Mallory. Even when mine was 'dead' and after I removed the pump, it still worked somewhat. I attached a hose to the intake of the Mallory and stuck it in a container of diesel, touched the wires off on the battery and got a good bath in diesel , guessing that it just didn't have enough life left in it to work under a load.



Did you notice any sporadic readings on the FP gauge before this happended ? Mine was jumping around from 3-12-1-15, etc. , as if the gerator was sticking and then releasing.



Hope this helps, if you need to get it rebuilt, you can contact the people here, mine cost $50. 00 and is now seating in the toolbox as a spare, if you needed to borrow same.



http://www.centuryperformance.com/index.htm



Scott W.

 

[Morphious]

It's the mallory, got to thinking last night, I now have over 80k on it. I installed it at around 40k on my truck, the odo reads 106k and I have oversized tires and the speedo don't work under 35 miles an hour. It failed again this morning out on the highly traffic inter dispersal loop in Tulsa, so I scrounged for some wires and did a quick wiring up to the battery with a toggle switch at the battery to ensure that it was not the power coming from the ecm. It is the pump. Was able to get it working again by banging it with a 5lb sledge and get the rest of the way to work this morning, with a stop every once in a while to "prime" the fuel pump. So I am going to have to track down another pump and get it ordered. It sucks that noone around here stocks them.



Morph.



BigSaint - who do I need to contact at century to get it rebuilt?

 

[Bigsaint]

Morph, I don't know the owner's name, but I get the same guy whenever I call. Also, I purchased my second one from him, I believe it was $186. 00 for the 4150. The century shop is close to Mallory, he drops the pump off and it's usually repaired by the next day. Let me know if you want to borrow my re-built pump, I could next day to you if you want to use it.

 

[MCummings]

Psst, Hey,

I know why your speedo doesn't work right. . It the Rear Wheel Speed Sensor (RWSS) Mine was going out exactly the way you say yours is "working". Mine got to the point that it would not register below 55MPH.

The Sensor is on top of the differential, and is an Easy Do It Yourself Job.

The sensor should be less than $50, but depends on the dealer you are dealing with.



MerrickNJr



EDIT: another RWSS gets replaced

 

[Bigsaint]

Any news Morph. ???



Scott W.

 

[Morphious]

Scott, sorry it took so long to get back to you, been to north carolina and back. Man is that a long trip. I bought another mallory thrusday at the local speed shop and replaced it in their parking lot, so I am back up and running. I am going to send my other one and get it rebuilt though. Thanks for the offer on the use of your rebuilt one, but amazingly enough the speed shop actually had one in stock.



Morph.



ps. Once I get the other one rebuilt, thinking about plumbing both into the truck and having a backup I can switch to in case of failure that way I am not down again like that.

 

[Bigsaint]

Glad to hear that you are back up and running, no doubt a stroke of good luck locating one at a local shop. I've though about doing same with my re-built Mallory, not sure if the pump would act as a restriction when not in service ??? If nothing else, it would save some time if I mounted it next to the existing Mallory, when I wired up the 2nd pump I soldered a spade fitting on the end of the hot lead, would be easy enough to solder up the spare so that all I needed to do would be to screw in the -AN/NPT adapters and plug in the hot lead, would have the ground already in place of course. Your thoughts ??? Are you going to wait for a failure analysis before/if you add a pre-filter??



Scott W.

 

[Morphious]

I have a feeling that mine is just worn out, Alot of hours with that pump running constantly. I chose not to run the prefilter mainly because I buy 99% of my fuel at the same location and it runs through a good micron filter there, plus on my tank I also have a filter before my pump spigot on my home tank.



What I had planned on doing is wiring it into a double pole double throw switch in the cab where I could switch between the two pumps. I figured I would Y the supply line out of the tank and put a check valve after each pump to ensure no flow back from the main line.



Morph.

 

[HVAC]

Brushes

My Mallory became inconsistant so I opened it up for a look. I replaced the brushes ($13) and cleaned it up with brake clean. It's fine now