Results 1 to 7 of 7
Thread: 1997 gmc yukon 5.7 fuel pressure
03-06-2014, 04:49 PM #1
- Join Date
- Mar 2014
1997 gmc yukon 5.7 fuel pressure
i have a 1997 gmc yukon that i purchased for my 17 year old son. figured be a great first truck for a new driver. been running great for 6 months till now .truck kept dying so i replaced battery .next day my wife drove it and died .started back up when i meet her to pick it up on way home i noticed my 17 year old didnt put gas in so was running low .as i proceeded up a hill the car would not exceed 30 mph and loud clanking noise coming from engine .proceeded to make it home put fuel in and it did get a little better .drove around and check engine light came on .bank 1 sensor 1 code and maf came up. all changed and still stalling every once and a while .oh and also changed fuel filter .today i changed iac valve running a little better .about an hour ago driving around will not exceed 30 mph but no clanking from engine .went to auto zone rented fuel pressure tester .numbers are as follows at prime 35
at start up 50
at 2500 rpms 52
holds at 50 for 20 mins then drops to 46
release air valve while running truck shuts off
please advise what to do next if you can thanks
03-06-2014, 11:38 PM #2
All of those numbers look low to me. If you cycle the key on and off a few times (to "prime" the pump more), does the pressure ever get near 60 psi? If you can find the "test lead" for the fuel pump (see a wiring diagram) so you can run the pump manually, can you run the pump so the pressure gets up near 60+ psi? If you carefully clamp off a rubber section of the return line, does the pressure increase? The highest pressure you list is 52 psi -- much lower than the spec of 60-66 that is usually given for these fuel systems. It suggests to me that something is wrong in the fuel system. At this point, bad pump seems most likely.'98 K1500 Suburban LS 5.7 L 4L60E NV246 ARB
'92 Ford Explorer XLT 4x4 4.0 L A4LD BW13-54 Trac-loc rear
"My toys were the greasy cogs and springs and pistons that lay around all over the place, and these, I can promise you, were far more fun to play with than most of the plastic rubbish children are given nowadays." Danny in Roald Dahl's Danny The Champion of the World
03-07-2014, 10:00 AM #3
Fuel pump problems are common with these; so are fuel pressure regulator problems. If the truck is holding pressure then the regulator is probably not the problem. Neither is easy to fix.
If you want to be sure you can duct tape your fuel pressure gauge to the windshield so you can see it while driving.
You will have to drop the tank to fix it, I think, unless maybe it's possible to cut a hole in the floor. Not that hard to drop the tank, be sure there's no fuel in it and then use a floor jack to support it.
I replaced mine with a cheap fuel pump and had to do it again three years later. Don't make that mistake.Minneapolis area - 1997 K2500 regular cab long bed + 8.5' Western Unimount plow + modified transmission + 2nd battery + modified camper charge circuit + 1971 Cayo camper -and- 2004 4x4 Suburban 2500 8.1 + Maxbrake controller + 2nd battery + modified trailer charge circuit + Reese receiver, pulls 30' Airstream trailer
03-07-2014, 10:21 AM #4
Yeah I would say fuel pump.. And if you still have problems check the pressure on the new one.. I have gotten a bad fuel pump(and sending unit) before and paid big money at autozone for it. I bought the replacement pump only(no sending unit) off ebay for less than $100. It came with a one year warranty (better than the local auto parts stores which were only 90 days) That one lasted.... yup you guessed it.. 1 year and 3 weeks... I actually bought another from the same guy only because of the warranty. They were AC Delco pumps too.
2011 Silverado CrewCab 5.3L*Ram Air Look Cowl Induction Reflexxion Hood*6" Pro Comp Lift*Flowmaster Dual exhaust*Perfect Launch Rear Diff. Cover*Led Smoke Taillights*L.E.D.Smoke 3rd Brakelight*60" L.E.D. Tailgate Bar*Rearview Mirror Reverse Camera and Sensors*Smoke Headlight Covers*Front Bumper Grill Insert*Deezee Black Alum. Diamond Rail covers*20" Ultra Motorsports Rims wrapped with 35.5"B.F. Goodrich Tires*Inchannel Raingaurds*CAI*Bullydog GT Tuner*Alpine Amp*Boss 6x9's*Boston Acoustic Subs*Terrantula Tweeters*Custom Sub box*Red Led Interior Accents*5% Ultimacool duo tint rear window and doors, 20% front doors*Custom Vinyl Graphics*Demolded*Debadged*Painted drums and calipers*
Future Mods Include: Custom Interior Hydrographics, Electronic Rollup Toneau Cover, 4.56 Gears, Painted rear bumper
03-07-2014, 03:52 PM #5
- Join Date
- Mar 2014
03-08-2014, 05:57 AM #6
You said you "almost" changed the fuel filter,,,well,, you "almost" might have had it fixed! That would have been the first thing I would have changed!
03-08-2014, 08:16 AM #7
Tags for this Thread