98 Blazer with 100K+, bought with 85K - no idea what service done prior.

Due to the common faulty fuel gauge, I ran the tank lower that normal for a day (usually keep above 1/2 at all times, has always been sluggish below 1/2). Went to start in driveway, and noticed the silence (no high pitched whine from pump). Put a few gallons in, hoping to simply be out - but still no whine.

Checked the relay - Good.
Fuel Filter - 1 month old.


Need to know if there is anything else to check or if the silence is a clear sign its died. ( have read the 98+fuel system diagnosis tread, FPR treads trying to diag the sluggish engine response, and the GMT370 Fuel tank removal tread. )

If dead, what pump is recommended, any additional parts recommended to replace during job (including parts to fix the bouncing fuel gauge issue), and any tips, warnings, guidance, req. tools, and prayers would be greatly appreciated.

Must do @ home if possible, medium skills - just seeking done-it-before wisdom and/or solid way to verify its dead ( again its dead silent - no whine).

Thanks

Job Update:

Finally died on freeway, no whine, dead pump. Dropped tank, and broke of vent valve removing hose. ARRRG! Of course I had the plastic tank with build in vent valve. Had gone back to parts store, got new vent valve, realized at home that the plastic tank vent valve is not removable, also new valve is much smaller. So, next ordered new 18gl dorman metal tank, waited my 4 days, valve went right in - but the pump I had bought earlier did not - ARRRG part 2, - -now had to order pump for metal tank, only one around was carter. It also went right it. Went to install back under truck, and although they look similar, the metal tank has a 1-2" lip around it. So ARGGGG 3 --- the straps for the plastic tank do not fit the metal tank, so had to find straps for the metal tank. Thankfully, after 13 calls found a store that could have it later same day.YEA!!! Again under the truck with my new straps found one of the two bolts inches to short. At this point I went in to load my 9mm. Went again to a hardware store, got same thread bolt but longer. Pushed it into place, bolt caught, (but there is at least 3 inches between strap and frame - with plastic had been touching) - concerning.

Refueled, opened cap, started up instantly. runs amazingly better. Also just did a bad front wheel hub, so everything is smooth and quite, engine response seems clean.

NOTE: be very careful with the vent valve hose ( actually all of them) - it breaks easy

 

AC Delco or Delphi for the replacement pump.

About the only thing I would check over first is that you are actually getting a good power & ground to the pump itself. You only need to drop the tank down a little bit to be able to disconnect the connector from the pump and test for power/ground. I added the wiring identification to the fuel pressure test DIY thread.

 

if you got a spare tire under the truck drop that and see if you can get to the plug on the pump.

 

Yes, I can drop tire and access pump. Assuming I can use my multi-meter to test current and ground.

When searching for part, a few places ask "with ENG code". Anyone know if that's standard in a 98 LS 4 door, or how to check?

Any feedback on Spectra pumps ( cant afford delphi - $150 more) I recall some brand in the forum that people were installing, and having to remove, return for another trying to get one that works.. Cant find thread again.

Also, to simply replace module & harness, do you need any specialty tools, fuel line disconnectors, etc.).?

 

you mean the 8th digit of the vin correct?

 

From experience with my '97, I can tell you, spend the extra $$.
I had put a Carter in mine. It lasted 14 months. (it had a 12 mo. warranty).
AirTex is equal to the Carter.
I also has a Delphi pump go bad after 20 months. A small hole in the feed line from the pump to the top of the housing assembly caused low pressure. I have that as a backup in case the latest Delphi goes again (installed in 2008).

The complete fuel pump assembly will have a new level sensor on it, so that will take care of your gauge problems. You'll probably have to splice a new harness connector onto the old harness (if it's the original pump).
If you do splice them, be sure to solder the wires together, don't rely on a crimp only.
The fuel feed line, and return line have pinch connectors on them. Pinch with a finger and thumb while pushing in, then pull out. The vent line will twist off with a slight push (it's round).

No un-ordinary tools required. Just metric wrenches to drop the tank cover, tank straps, screw-driver to remover the filler hose and vent tube (I had to cut the rubber joiners from the tubes to the tank due to old age, got replacement rubber tubes at parts store, ~$10.00.)

 

i say go with the ac delco or delphi if your gonna get cheap parts there gonna fail on you later on and then you gonna end up paying twice the price

your choice

 

Waited another day, tried to start. Whine was there, blazer started. Quickly drove to station and put in more gas. Drove 20 miles to get new fuel pump, restarted many times. Anyway, strange behaviour, relay's are either good or bad, not intermittent. Ground connect could be culprit, but suspect its still a pump failing. Float could be failing or got stuck down causing the initial pump off condition, and prior gauge issues.

Not going to overthink it, still proceeding with replacement to play it safe.

Just hard to tear into a hairy job, when its actually working ( ie..don't fix it if it ain't broke).

 

Just replaced my fuel pump today... it was a little harder than I had figured due to the fact that I wasn't thinking and filled up my tank the other day so it was quite heavy for one guy to do alone, especially when you don't have a lift and have to do the entire job laying on your back in the drive way! Grrr. Lol. The good news is its now done And runs like it was brand new. I used a delphi pump, I wasn't going to take any chances... its amazing the troubles one little pump can cause.

 

The fuel level sensor is a separate circuit for the gauge only, and has no shut-off circuit to interrupt the pump.

Do you know if this truck has the original pump?, or is it after-market.
The Carter pump I had in mine would be intermittant. Would run fine, all of a sudden, nothing. Let it sit for a day, would run fine again, but not restart 5 minutes after turned off.