So, a quick history of fuel pumps in my van. When I first bought the van I needed to turn the key to the ACC position to prime the pump every time in order to start without cranking for several seconds. After some testing, primarily a fuel pressure test, I determined the fuel pump was bad and replaced it with a cheap one because I couldn’t afford the more expensive ones at the time. Then a few years later (this was probably March 2025) I went to move my van and it would not start because no fuel was making it to the engine. at this point I was in the middle of rebui9lding the interior of the van because it was a camper conversion. in that process I unplugged the rear wires below the tail lights on the interior, I was unaware that this is where the fuel pump power or ground came from. so I ordered a new Delphi fuel pump, from my understanding this should have been one of the better quality pumps. I found out during that install that all I had done was unplug the fuel pump, but I figured I already had the new higher quality pump and the tank dropped so I might as well put the better quality pump in there. Fast forward until April 5th of this year, I was driving into Colorado springs when all of a sudden my engine shut off. after some diagnosis I determined the only cause could be a bad fuel pump. the only one that any parts stores around had was a precision brand pump. so that’s what I got and replaced it on the side of the highway. the day after I replaced the pump, I all of a sudden had no power going up hills and was constantly dropping into second gear in order to make it up hills that I would barely call a hill (maybe a 1-2% grade). shortly after that I noticed when I shut the van off I could hear all the fuel drain back from the engine to the tank. actually it was draining on top of the tank then rolling down the sides onto the ground. so, I ordered a new pump and went to get it the next day. when I got to the parts store I dropped the gas tank and noticed 2 things. one, that the bottom plate on the filter had fallen off the pump and therefore wasn’t filtering fuel and 2 that the pressure regulator had popped out of the socket. the pressure regulator problem told me why the fuel all of a sudden started draining from the system once the van was shut off, and why it was draining on top of the tank. as for the filter issue, the tank overall was relatively clean, but there were a few bits of debris in the tank. these were my fault as when I was building the interior I drilled through the floor and at the same time though the top of the tank, I had since patched that hole, but it looked like the debris was plastic shavings from when I drilled the hole. I pulled some of these plastic shavings out of the pump, presumably this is why I wasn’t having much power the day after I replaced it. my best guess is that bottom plate fell off and the pump sucked up debris that damaged it. also the fuel pressure test on this pump was reading ~42PSI which is low but not critically low, I’m pretty sure the spec for this pump is minimum 49PSI with an operating range from 40-60 or something like that.

So I pulled the pump, the only one I could get that day was also a precision brand pump. as I installed that I tested it before reinstalling the tank and it produced 0PSI of fuel pressure. I then id the pressure test at the pump rather than at the fuel rail, and I used a jumper wire in the relay socket to supply c0onstant power, the pump turned on and produced still 0 PSI. so I went back into the store and traded them back for my old fuel pump, because at least with that one I could drive the van. I used some fuel safe JB weld Steel Stick to glue the bottom plate back on the filter so I could drive it while I searched for a new pump. and since that re install (yesterday) it now makes 35PSI, which I would consider critically low. Also I can now only drive for about 10 minutes at a time before the pump starts to cut out. my guess is with the low PSI the pump is working harder to maintain fuel pressure and overheating, because I can stop and shut the van off for about 5-10mins and it will run fine again for another 10-15 minutes (depending on speed and hills). tomorrow I will be limping the van ~45 mins up to another parts store that could get any fuel pump for this van in less than 2 weeks. unfortunately the only options were more precision brand pumps. so I had them order 2 in case another is bad out of the box, and I will be replacing that tomorrow.

Looking at everything else in the system, because it seems strange to me to going through so many fuel pumps, I cant seem to find anything wrong. it is possible I guess that a fuel injector is clogged or not spraying correctly, but I’m not sure if that would cause pump failure so quickly, and also when the new pump was installed it worked great for the first 10 miles, this would lead me to believe the injectors operate normally when the pump works. there’s no breaks int he fuel line to reduce pressure, and there are no leaks at the fuel rail or any other signs that indicate the fuel line/ rail system is compromised. I also recently replaced the Spark plugs, cap, and rotor after the Colorado springs pump to make sure the lack of power wasn’t fouled plugs from he old pump failing or some other part of the ignition system that could be the reason I had no power up hills, so I’m fairly sure that the ignition system has nothing to do with the low power, just that pumps keep failing.

With that information I have 2 questions. first, is there anything I can do to the precision brand pump to upgrade it or make it more durable than the out of the box option? I would like to make this one last longer than 3 weeks if I could. Second, I would like to buy the absolute most reliable pump I can to carry for when the precision pump fails. that way I already have the good replacement on hand for when I break down in the middle of nowhere. so what is the best quality pump for these vans? form my understanding there aren’t many great options. from what I can tell the original one I replaced was the factory one that lasted ~150k miles (I have nearly all the service history of the van after 20k, so unless the pump was replaced in the vans first 20k miles, I’m really sure it was the original pump). the Delphi only lasted ~10k and the of 2 precision ones I’ve had, one was bad out of the box and the other lasted about 10 miles before I had no power.

As a secondary question, is it worth considering trying to find a way to mount an external pump, filter, and regulator system. I know it doesn’t seem to be a common thing to do, but I live in the van and on the road, its difficult every time I have to drop the fuel tank to change the pump. is there a feasible way to install a high pressure external pump system in a van like this so I can change the filter occasionally and if the pump goes bad is a couple high pressure fittings and the screws that hold the pump to the frame that I have to replace, or is that not really an option?

 

For the most part, the Delphi pump *should* be pretty reliable. They are an OEM supplier after all. (for GM at least....) When I was having fuel pump issues, I went thru three of them before I finally figured out what the actual problem was. Bad Ground. I drive a truck though, so, not sure how much different the Van is going to be. But, on mine, the fuel pump grounded at G100, along with a selection of other systems. As it turns out, more than half the wires going to that ground had corroded away, or only had one or two strands of wire left making a connection. I addressed that issue, and have not had a problem since.

 

I just got the new fuel pump, again. I tested the ground with my multimeter to the chassis and got a continuity of 0.00, I don't think I'm able to access the ground lug location for the fuel pump because of the rv tanks installed under the van.

The new pump does actually pump fuel but at my fuel rail I'm getting almost no pressure and when I release the pressure from the tester it's all air. I'm sure the pump reaches the bottom of the tank, and I have about 1/4 tank of gas in the tank. It does send fuel up the line and to the rail but for some reason it doesn't seem to make it to the pressure tester and the engine runs like it's not getting fuel with the new pump either. Any ideas what could be going on here?

 

Continuity does not imply that there is enough wire to carry the current load to maintain proper fuel pressure. Depending on what year your van is, min fuel pressure may be 39PSI, or, if it's 96 or newer, 49PSI...... The PCM can compensate to an extent, but, an engine that wants 49 PSI, you'll be lucky if it starts at 35......

On my truck, the fuel pump grounded right behind the radiator support...... drivers side. Don't know where it would be on the van.

 

Unfortunately it was a simpler solution than that. When the tank was on the ground I failed to notice that the ground sloped back more than the tank would sit in the straps of the van, once I shimmed the tank up I had not problems and it shot straight to 49 psi. Haven't road tested yet, will update once I do to make sure that was the problem lol.