Hi guys,

Been reading every fuel pump, regulator post for the last couple of days, haven't quite got this one figured out yet. Here goes.

2001 rcsb 5.3 85k miles

Last thursday was driving through a parking lot at slow speed, hit a sharp speed bump(truck has z85 quite stiff rear suspension bed was empty) and the truck for the first time since I bought it a year and 10k ago sputtered, rpms fell to 100-200rpms and pressing on the accelerator didn't allow it to catch. It reacted like this for maybe about 5 seconds, so I let off so as not to flood it and it picked itself back up to its usual 500 idle rpms.Tank was 3/4 full. Weird.

Of course it's in my head now there is a problem here, so later idleing in traffic I'm almost certain the truck has the slightest shaking on the brake and on light acceleration and maybe has lost 3-5% power(been crazy humid too).

Can't sleep that night thinking about it and I'm leaving on a trip on Sat so I go for a 30 mile ride small streets but mostly hwy and eveything works fine.

Friday decide to test again going out for icecream, 20 min drive not a hiccup again.

So Sat morning friend shows up we load two streetbikes in my truck, truck starts perfect, top up tank starts perfect again and hit the road for a 3hr drive to some awesome roads up north. Not 20 minutes into the trip I'm heading up the span of a bridge and I loose major power, same as thursday, give it gas, feels like it's on 20% power, rpms are down not dead yet ,sputtering and just as I crest the top the engine dies. I roll down on momentum in neutral, and manage to restart and exit off the bridge still sputtering a tiny bit. It all happened so fast I'm not sure if it came back fine itself while running or if after I restarted it, but it ended up running smooth and I returned without incident to the house to reload and take his truck.

Got back sunday night turned truck over in driveway started fine, didn't drive it. Didn't touch it tues, but today I went out to have a go on some of the stuff I read about. Started it and it was doing its low rpm sputter, tried to back it up the incline and it couldn't take or was not getting enough fuel I imagine to back up. I spent a couple of minutes stalled in the street trying to get the truck back up and managed by getting revs up and dropping it into reverse. Seems to occur at only at low rpms 200-1500rpms. Once past this seems to rev pretty good. Once I made it to the top of the driveway, it starts working fine and revved perfectly through all the range. Weird.

Starting the cheapest way, picked up and installed new fuel filter this evening, old one looked good and was certainly not the original, it came out pretty easy. Checked fuel regulator for gas coming out of vent tube, and none seen. No codes showing up.

Truck started perfect this evening after the fuel filter change, I took it for 30 minute in town drive alot of stop and go, and it ran perfect again. SO.......

It's killing me that is occuring intermitent. While I am not closed to other possibilities, I believe it is fuel pump related, just by the way it went out on me on the bridge. I've had a car with a faulty distributor harness go out and that occurs instantly. Doesn't feel electrical. Electrical is usually more abrupt. While the speedbump would propose possibly a short circuit or something, it did the same just starting it sitting in my driveway.

I do not have pressure gauge and I have a feeling if I show up at a garage with the truck running fine, I'll be out the money for the test reading fine. Pump cycles upon key twist and does not make any abnormal noises. I do not often drive with low fuel level, try to maintain 1/2 a tank.

Dealer here wants 516cdn for a replacement pump and part store wants 450cdn for off brand unit. Its killing me to put this in without knowing for sure if that is it. If they were 100-200 I would do it as an elimination factor no question. I also don't really want to install the wahlbro style units and have to cut and splice and modify the bucket and have to crank several times because of check valve missing. I would prefer to do a plug and play replacement(oem style).

Seen some ebay complete modules for 80-200usd listed but I dunno, they all have connectors to splice in outside harness, and one even listed said runs at 44psi(don't we need 50-60 min!!), so are the other ones the same. Has anyone tried a cheaper aftermarket and gotten good reliable service from it?

Let me know what you guys think, which direction I should take, this money was for a cam purchase but I guess I have to fix this first!

Thanks in advance for any ideas you can throw my way.

 

A lot to read up there, but why not get a fuel pressure gauge and test the pressure, shoul be a constant 58psi.


Tuneup lately? old plugs and fuel filter will cause headaches

 

I know, didn't want to leave out too many details. Helps you guys have a better feel for what has been happening. Fuel filter changed tonight, no plugs done yet but engine runs well at times and drastically not at others, so I can eliminate plugs, though I agree they will be due after this.

I think I may have to break down and buy a pressure gauge but I haven't seen much under $100cdn around here.

 

I would like to know whats up too. My brother is having the problems as you but a little worse. His truck is having the symptoms all the time tho and getting kinda dangerous, He jumped in a turning lane the other day and trying to beat a yellow light and cars coming, the truck sputtered in the middle of the intersection and he was almost hit in the pass door (where I was sitting) Scared the out off me. lol We've replaced plug and wires, fuel filter, coil packs, We are at bad fuel pump or injectors clogged.

 

I think its the fuel pump. My 04 denali did the same thing.

 

off brand fuel pumps are available for like $300 bucks. No sense in spending 450 or 550

 

get a walbro 255 and put it in the stock bucket with a few small mods I think. do a search for it. 255 is ~125.

 

Hey Bowtie, have a feeling we are experiencing the same thing for sure.

Just went to a buds house to swim and truck did the exact same thing in the intersection as well. Nothing oncoming, but the others waiting to cross weren't too impressed. I think I am going to bite the bullet and change the fuel pump.

Just need to figure out which one to choose. I'm so-so on the wahlbro because of spliced wires in the fuel tank as well as them not having check valves to hold pressure. I prefer an OEM style but not OEM prices. On top of it I have to figure out which pump I have. It would seem there are 2 versions available for my model truck.

 

Well if you buy oreillys off brand pump for 300 like I did (twice in 160K) then you will still have to splice the wires, they utilize a better connector design that requires you to splice.

Open the box of whatever you choose and check to see if it needs to be spliced

 

im about to order a new fuel pump..mine kinda does the same thing..but i have extended cranks on start, have to prime it twice and then its fine..sputters when im low on fuel etc

I dont really want to spend the 350 on a pump either..

Anyone tried anything off ebay? are they guarenteed to fail or what?
something like this?

http://cgi.ebay.com/ebaymotors/FUEL-...ht_2245wt_1165