Hi all! I'm new to posting, though I've been lurking for quite some time. We're having issues with my fiancee's Blazer and I've decided to seek the advice & general opinion of some of the forum-goers.

We have a 1997, 2dr 4x4 Blazer LS. Since January we've replaced the ignition and all electricals in the steering column due to a crazy electrical problem (intermittent starting, power windows stopping, no brake lights, no dash lights..ect), the starter and the radiator, thermostat & heater hoses. ALL that being said, there now seems to be an issue with the fuel pump.

The Blazer runs like a champ. Never acts starved of fuel or stalls. But, it's gotten to where sometimes the fuel pump will turn on and sometimes it won't. All day yesterday - nothing. Today - primes and fires up every time. Is this an indication of the pump going bad or could it be electrical? The ECM BATT fuse is fine and the relay in the glove box is switching on. I'm at a loss as to what it is as I'm no expert on fuel systems. Any thoughts/help will be greatly appreciated.

Thanks,

Greg

P.S. Fuel consumption has gotten progressively worse and the fuel gauge itself is prone to freak-outs where it will spin like mad. Also, the filler neck has been removed from the body once before (missing screws/bolts) as well as the glove box where the relays are (missing screws/bolts) I can only assume that either the fuel pump has been replaced once or that this was also a recurring problem for the previous owner.

 

Hmmm... Well if it was mine I'd be inclined to toss in a new pump-BUT you are relating some other issues which are probably a factor as well! This has been addressed on this forum-do a search! Also wait till some of the other members chime in: their knowledge is usually spot-on! Remember that the pump for the 2 door is not the same as the 4 door! Please provide mileage on the unit as well,thank you and good luck!

 

Thanks for the response! I've searched numerous times and haven't come across any threads that are helpful to me. Maybe I'm just not looking right? Who knows? I'll do some more searching later today. The Blazer itself has about 140k on it, not sure how many are on the fuel pump. I removed the gravel shield this morning under the tank and it appears the bolts for the tank straps have been removed at some point so I'm willing to bet it's not a stock pump. Is there any way to tell what brand pump it is once I get it out?

Thanks again!

-Greg

 

You're dealing with a 1997. You'll be thrilled to know that year is an electrical nightmare {aka Cluster____}.

That said.. it's possible the problem is indeed the fuel pump, or the harness connector especially if it's a 2x2 contact arrangment.

You only want Delphi FG 0072 or AcD MU 1755
both for 2dr and both should have the 1x4 connector included which you should SOLDER in, NOT use butt splices.
Check ebay.. but read desc closely and only buy from 99% feedback.
Some pumps read like they're ACD but arent.

IIRC, the wire from the FP relay socket to pump is gray same as later models. Ohm there to grd when it doesnt want to run. If less than ten ohms, pump probably stalled. Verify with smacking tank with board while key-on {withiin 2 secs}
If higher than 15 ohms likely bad connection. But, again at the FP.

 

Thanks, pettyfog. To say 97's are an electrical nightmare is an understatement!

I've got the tank unbolted and the hose clamps loosened. How far down should the tank drop when I lower the jack? Do the hoses cause it to stay elevated until they are completely removed? Every tutorial I find has a long tank down the side, this is a square tank in the very rear of the blazer just behind the tow hitch.

 

They will, so be careful of breaking the hoses or something even more expensive to fix.

Most tanks on any car will only drop a few inches without disconnection of everything. Hoses and tubings giving less leeway.

 

I dropped the tank successfully and removed the fuel pump. Hardly any room at all to remove those hoses and fuel lines. Crazy tight under there. I'll be purchasing the one mentioned above from Advance online with a 25% off code so it'll be roughly $100 off. Not bad. The old pump is an ACDelco that's about as yellow as the sun...this thing has to be the original. Gonna go out in a few and clean the tank itself out and dry it with the air compressor. Thanks to everyone for all the help so far.

Edit: Advance is trying their best to sell me on Airtex. Even going so far as to claim Airtex now makes all ACDelco fuel pumps & that when you buy Airtex it's ACDelco without the ACD badge. Is this guy for real? Sounds like b.s. to me.

 

OK. I'm thinking of going with a Walbro fuel pump. I've read good things but would like an opinion or two.
Walbro TU411 OE Replacement Fuel Pump Kit from Fuel-Pumps.net

Delco and Delphi are just not in my price range and I've read Airtex is the spawn of Satan, so this looks like the most viable option for me.

 

Dunno man its up to you

I have never heard of these pumps ....

 

Walbro has been around since the 50's maybe even before that. Typically their quality is pretty good, but why take a chance when you can an AC Delco for less?

ACDelco MU1755 Fuel Pump Module Assembly 25344816 25178732 | eBay