Having an annoying issue with my blazer. When I go to accelerate after I have been driving it for a good half hour or more, it stutters, really bad. It all started after running my tank dangerously low (my fault, I thought I had more but it dropped quicker than I anticipated). I thought it was stuttering because of how low on gas I was, so I thought nothing of it and topped off the tank. It was good for another 150 or so miles. Then, in a traffic jam on the freeway, I accelerated back up to 70 after traffic cleared, and it stuttered again! But this time I had just over 1/2 tank.

Basically, when I hit the gas to accelerate, it begins normal and then it jerks and bucks violently, the rpms jump from 1600 to 2400 and back to 1600 very quick. Its like it wants to go, but it gets choked off or something. It will continue stuttering until I let off the gas. If I cruise gently for a few miles and then give it gas, it accelerates like nothing ever happened. Also, When it does begin to stutter, If I turn off the ac It seems to help. Maybe just because it takes a load off the engine?

I have no hard starting issues (except for winter, where instead of taking 1-2 seconds to start it takes 2-3. Also when really hot outside, if I stop at a rest area and then start it up again, it starts kind of 'weak' for lack of a better term.) It does seem just a little sluggish to me when driving as well. It takes more pedal than I would like, just to keep of with traffic. The part that concerns me, is that the fuel pump has been whining lately, really loud. The whining also changes pitch, even while idling. Something's a miss here. Anybody have any ideas?

 

Any check engine lights while this is happening?

sounds like it's time to do a fuel pressure test. That will at least tell us if the problem is fuel related or not.

 

That completely slipped my mind. It came on the second time the truck acted up. Luckily I always have my code reader. The code was for the catalytic converter (Which I don't have at this point in time, the code was p0424 I believe). I have had that code a few times before, but the truck always acted just fine. Also I keep getting p0442 (small evap. leak) which I have had for about a year now. I will do a fuel pressure test and see what happens.

 

Just a little update.. I have driven it roughly 40 miles since the troubles, and I haven't had one issue. The fuel pump is still very loud (high pitched whine), so I have decided Im going to repair/replace it anyways, since that's most likely the issue.

Has anybody had good experiences with these? Clicky
Its an ACDelco fuel pump repair kit. Lots cheaper than the whole acdelco unit, Im sure I could do it myself. The trouble is, I have no idea if my fuel pump is original or not, so I have no idea what brand pump is in the tank. Is there a good way to tell without dropping the tank? I have noticed that the pump that's in there now has two 1x4 connectors, but I keep hearing that original pumps had one 1x4 and one 2x2 connector. Is that correct?

 

running a pump dry has the risk of burning it up and damaging it. These fuel pumps tend to be noisy anyway so dont worry about that too much.

What I think is more likely is since you ran it so low it sucked up trash and it plugged up the fuel filter, some how it may have worked its way free or at least not blocking flow any more. Change your filter. I would do that before the pump. Dont buy a repair kit, just get a pump. You "may" be able to see the wires if you look in between the frame and body from the rear wheel well.

 

Well I put in a new fuel filter, no change. Also, the fuel pump was starting to drop pressure intermittently and cut out sometimes.. So I ordered a new pump the other day (ACDelco). Got it in the mail today, and now I have a new problem!! The fuel tank strap bolts were very rusty.. The front strap bolt completely snapped, and the rear strap bolt is spinning in place.. Its not stripped, but the stupid nut that they weld in the cross member that the bolt goes into decided to break its welds. Is there any other way to get the bolt out, besides cutting it?

I swear, its ALWAYS something with these trucks!

 

For me all 4 strap bolts spin so I put a size 18 I believe wrench on top and spin it till it gets wedged and go from there with a socket wrench on the other side. I recently just went through bad pumps and a regulator. I agree, one thing after another, lol

 

Well I ended up cutting that bolt. Autozone has the replacement bolt/nut so I bought that. I also ordered a new front strap (with the bolt sticking out of it.. I ended up snapping the old one anyways) from my local Chevrolet dealer, ended up being around 17 bucks.

Got the new fuel pump put in today anyways. The old pump indeed was in need of replacement. the pickup hose had a small crack, and the sock/strainer was FULL of sludge and dirt. Its a wonder it even pumped gas anymore!

While I wait for the part, I 'spruced' up the tank. Got it clean and ready for installation. Going to pick up my new strap tomorrow, install the tank, and hope for the best!

 

Bet you`ll be fine and comfortable that the tank wont fall off!

 

Yeah definitely. Might as well get it done right the first time!

Nice Blazer by the way