97 5.7 fuel pump diagnosis
 

have the actual fuel pressure checked. 60 psi, with no less than 55 at idle. if you get these numbers, fuel pump is ok. anything else, replace it. however, based on personal experience from myself and many other members, buy the actual delco fuel pump. spend the extra few dollars now, or you will be back into the tank again shortly, spending more than the delco pump would have been. trust me.

It could be the pump which is very common on those trucks. Or you may have 2 different problems. A restricted fuel filter is just as common as the pump if not more. I probably do 2 fuel filters for every 1 pump when a customer has the same complaint in a GM truck. A lot of GM trucks have inop fuel gauges which is always the sending unit which could be replace separately from the pump. If you have a fuel pressure gauge you could check the pressure as stated above but if you do not you may want to try a $15.00 filter. As far as 13 MPG that could be pretty close too correct , my 2007 only gets 12.9 MPG. I know my old 2000 5.7 2wd Tahoe Limited got a LITTLE better than my new one but I am not sure how much.

Those two are on the money. ^^^^

tested fuel pressure is 61 with the engine off & 55 running, should I buy the Delphi pump? Could it be the injectors, or is it the pump for sure? She runs well until you try to pass or climb a steep hill.

Replace fuel filter first. A restricted filter does not always reduce pressure, it can reduce the volume enough to cause your problem.

Ok I replaced the filter & it runs the same as before...I'm going to buy a Delphi pump & have it installed Monday night...

The filter was good, he could blow through it, but we replaced it anyway, no improvement. It still only cruises smoothly & will not accelerate without stuttering

In the good old days a miss under load could be caused by the ignition system, (bad spark plug, bad plug wire, carbon tracked distributor cap,) But I assume yoou have checked all that.

My gas gauge is stuck past full. It creeps towards the F in full when I shut the Burb off, but does not fall left of the F. Today, we'll install a fuel pump & strainer, but not the sending unit. I cannot afford the sending unit and can estimate my fuel level. I hope the pump will make the Burb run like new again. If anyone tells me I'm stupid not to do the sending unit now, I'll borrow the extra money from someone. I'm being told that the pump itself is $75 & the strainer is $10. The sending unit complete with pump is $235. I already spent $95 installing a new filter & checking the fuel pressure last Friday. Again, the pressure was 61 off & 55 running. I have not checked the plugs or anything else, but my mechanic will before installing the pump. At first I thought it was only needing a fuel injector cleaner to run better. Then I added a BG trans conditioner to ensure she shifts smoothly. She runs well until you climb a hill or try to pass a vehicle. That is when she sputters like she needs better fuel pressure.