28th Aug 2007, 21:26

If you replace the fuel line it shouldn't bog at high speeds. Also it will seem to have more power. I had the same prob with my 1500k 5.7 and it fixed it. I also replaced the fuel filter.

14th Dec 2007, 09:33

I have owned my 97 gmc sierra for 5 years and I have changed the fuel pump 3 times already. Now my truck is sitting in the driveway and it won't start AGAIN... The truck never chugged out or anything, just went outside one morning and it had a hard time starting, that was 2 weeks ago, last weekend I woke up and tried to start it and it wouldn't start... Any suggestions???

17th Dec 2007, 12:56

If you arced the battery, you might have blown a relay or fuse. That or you might have fried the wiring to and from the starter. Check all connections with a multimeter and do the basic rundown first- cables, fuses, etc.

18th Dec 2007, 07:50

I have a 97 GMC Sierra. The transmission starts to jerk really bad at 55-60 mph. If I slow down or speed up it stops jerking. Can anyone tell me what is wrong?

14th Jan 2008, 19:39

It's not the transmission. DO NOT go replace the transmission. I have a '97 Chevy Cheyenne 5.7 1500 that's been doing the same thing, but it's gotten to the point where is gives up when I try to get on the gas. I've nickel and dimed myself to death hunting for the problem. Travelling through town is fine, just can't handle bridges or anything that requires a load of fuel to be dumped in or rapid acceleration. It's the fuel injector system on the Vortec. The Chevy design is prone to failure. Napa makes an after-market improved design that goes for less than half of what your going to pay at the dealership. You're still looking at about $500 though. If you have the Vortec TBI, I seriously suggest you look into the injector. You'll need the regulator ($52.90), gaskets ($28.59), injector ($288.87), and mounting clip ($8.27). Good luck! Oh yeah...change the fuel pump too...that's gonna fail on you as well. Mine happened during a thunderstorm!!!

30th Mar 2011, 23:35

Man, I just bought a used '97 GMC, which I love, as an ex Ford man, but drove a near 400 miles trip, and had strange engine lights, and still other small issues.

3rd May 2011, 22:35

Have a '97 GMC K1500 with 5.7 Vortec and 5-speed manual tranny. Similar problems every one else seems to be having. I had to replace the intake manifold gasket virtually fresh out of the factory. It has 89,000 original miles on it now, and I just replaced the radiator with new top & bottom hoses and the water pump. I have a theory that the corroding coolant gaskets is due to the DexCool coolant (the orange stuff, which is very corrosive). I'm seriously considering flushing out the whole system and changing over to the regular green coolant if my intake manifold gasket blows again. I get a faint coolant smell still after replacing the radiator and water pump, so I'm suspecting the intake again.

Early on, I had some fuel delivery problems too that nobody could seem to diagnose. I replace the fuel filter every 12K, and seems to be cleared up now.

The tranny is still going strong although I did replace the OEM clutch with a Centerforce dual friction clutch.

Other than that, K&N air filter, March underdrive pulleys, Hypertech program and converted to true dual exhaust with Flowmasters.

Love the truck, but it has nickel and dimed me over the years.

13th Jul 2011, 09:03

If you have to keep replacing coolant but see no leak, I think that you have a broken head gasket. Have it checked out as soon as possible, as you do not want to crack the engine.

11th Oct 2011, 14:40

Yup, I've had a '97 5 liter Sierra since new, and have had THREE transmissions go bad, intake gasket failed that mixed oil/coolant, fuel pump failed... all in the first 100k miles. I almost qualified for the California lemon law.

10th Dec 2011, 22:27

I spent 50 years working on GMC, Ford, and other makes as a certified mechanic, so, I speak from experience, not that I'm necessarily the sharpest knife in the drawer.

About failing or failed in tank GMC fuel pumps.

The fuel pumps on the 1997 GMC 5.7 and other years all have the same problem; the torpedo pumps generally fail within 2 - 4 years, regardless of whether you have a fuel pump strainer installed, keep the tank filled to capacity, and have a high quality fuel filter installed. Basically, they are junk.

I've read so many comments on this fuel pump issue over the years, and most are way off base with regard to fuel pump diagnosis, but the most ridiculous of all is, that one must purchase an Original Equipment AC Delco fuel pump, because the others are basically junk.

First of all, the majority of all these fuel pumps are all manufactured in China, the only difference being that they have their name or logo stamped on them... "Original Whatever Name" that is stamped on the pump means absolutely nothing. As long as the pump is assembled in the U.S. it can be identified as original equipment made in America, when in fact all the piece parts were manufactured in China. So, you can pay $100.00 or more, or you can pay $19.95 plus S&H from Genesis Auto Parts and get the same quality, (I don't work for anyone, I'm retired).

Bottom line, I've replaced three (3) fuel pumps in 11 years on my GMC 5.7, and I've listened to 100's of complaints about GMC failed fuel pumps; you can find this information all over the Internet.

So what is "Original GM Equipment" anyway?

Here's one example, I recently replaced the ignition control module on my 1997 GMC. When I was removing the defective one, it was stamped "GM" on the front, implying that it was original equipment made in America of the highest quality... BULL, when I removed the module, on the back of the device, it said "Singapore".

Back to the pump issue.

The bottom line, you're going to have to live with this fuel pump aggravation and replace the pump numerous times over the time you own the vehicle. I would suggest that you replace the fuel filter at intervals of no less than 10,000 miles. Also be sure that you install a gas strainer on the pump when you replace it. These pumps overheat easily if you keep your gas tank too low.

You also need to know how to perform a proper test to determine if the fuel pump is beginning to fail or is actually dead. Spend $30.00 and get yourself a fuel pressure gauge; most come with adapters for both GM and Ford vehicles.

Here are the tests that you need to perform.

Be absolutely sure that you inspect your fuel filter for restrictions before performing the following tests. Some fuel filter brands are known to have filter elements that can actually swell and restrict flow. Be sure that your coolant temperature sensor has been checked and known to be good, that's the one that generally sits up front near the thermostat housing, it can also cause hard starts. Having verified the above, we move on.

Perform the following tests when the vehicle is STONE COLD, let the vehicle sit overnight, then perform the tests. This is important, because if the vehicle is warm, it may start, but when cold, it won't start.

1. If your vehicle starts hard, or when it's stone cold, it fails to start at all, or requires numerous cranking attempts to get it started, or requires that you spray starting fluid or pour a few drops of gas into the throttle body, your pump is on the way out or DEAD.

GMC vehicles have a fuel pressure port on the fuel line under the hood, it's a Schrader Valve port where you can attach the gauge. Now have someone sit in the vehicle and turn on the key (DO NOT CRANK THE STARTER/ENGINE), now observe the reading, it must read at least 60 - 65 PSI; if it reads "0" the pump is dead, if it reads below 60 PSI and does not drop to "0", you have a fuel pump issue that's in the beginning stages of failure. Assuming the fuel pressure met the 60 - 65 PSI requirement, go to step two (2).

2. If the gauge does read 60 - 65 PSI, now have your friend crank the engine, and read the result. If the gauge drops below 50 PSI but does not go to "0" when cranking, your pump is on its why out and will either cause hard starts, or not start at all without a priming assist with starting fluid or a few drops of gas poured into the throttle body. Anything below 50 PSI when cranking, you are going to have to replace the pump. Most fail to perform the cranking test and misdiagnose any fuel pump problem.

Obviously, if even with priming, the vehicle won't start, the pump IS COMPLETELY DEAD.

YES, there are other things that can cause hard starts or failure to start at all, however, 99.9% of the time the tests noted above will reveal a fuel pump problem.

Hope this helps.


25th Dec 2011, 04:32

I have the same problem with my '97 Sierra with the 5.7 in it.

14th Aug 2012, 18:19

Try looking for any signs of a head gasket leak. Explains a lot of your problems. Just a suggestion.

29th Jan 2013, 20:53

What was the cause of not starting?

23rd Sep 2015, 01:58

Hi... I have a '97 GMC Sierra 7.4. I have the same issue... could it be just a regulator problem or filter issue? I'm trying not to have to replace the pump... NOT an easy job! :-)

Thank you! Cassie Barner.

7th Oct 2015, 14:36

Hello, I have a 1997 GMC Sierra 1500 3 door with a 5.7 motor (a V8). I cranked the truck and water started pouring from underneath. I looked under the hood and it looks like it's coming from behind the alternator. I don't know what that is called or what it can be. Any help PLEASE? It has 212200 miles.

16th Mar 2016, 23:21

Replace cap and rotor.

20th Mar 2016, 02:50

I sand the burn marks off of the rotor and reinstall it. This saves a lot of money. Same as spark plugs. For fuel filters I rinse them through with brake cleaner. There is no need to buy new parts.