Mechanics

CHEVY 98 HESITATES ON ACCELERATION WHEN

1998 Chevrolet Blazer

Engine Performance problem
1998 Chevy Blazer 6 cyl Four Wheel Drive Automatic 175000 miles

I have a 98 chevy blazer. I have been scouring automotive repair websites and have seen many blazers running into this problem. When the truck is cold it hesitates badly sometimes almost to the point of stalling out it seems but never quite gets there. I just had a full tuneup and have taken it into the shop 2 times already and the mechanic cannot figure out whats going on. As soon as it warms up (About half an hour of driving) it runs great. I just had my fuel pressure checked and it read at 55. The weird thing is that the computer is not throwing any codes at all, had it scanned twice. Cleaned the maf sensor and that didnt work, also had the Idle air control valve cleaned but not replaced, thinking about the coolant temp sensor but Im not sure if thats it. Please can someone clear this up for me once and for all!
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JaredWilske6185
February 24, 2009.




Fuel pressure for your vehicle should be from 60-66 psi, anything less wont run properly. Does the pressure change when you rev the engine?
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Tiny
Jack42
Feb 25, 2009.
Im not sure if it changes on rev, but from what youre telling me it sounds like my fuel pump might be going bad? I just had my fuel filter replaced so that cant be it. Anything else to try before I start into my fuel pump?

Tiny
JaredWilske6185
Feb 25, 2009.
Low pressure is the pump, if the filter has been changed. The pressure should increase a little on therev if the regulator is working right. I do suggest an A/C Delco pump though

Tiny
Jack42
Feb 25, 2009.
Is there any kind of test I could do to make sure that my fuel pump is going out before I go spending the 300 dollars to buy a new one?

Tiny
JaredWilske6185
Feb 25, 2009.
Basically if the pump doesnt put out the pressure and the filter is new, the pump is all that is left

Tiny
Jack42
Feb 25, 2009.
Ok, so would this be something that a weekend warrior could do or would this be a shop only deal, because I know that the pump is in tank so. I wouldnt even know where to start.

Tiny
JaredWilske6185
Feb 25, 2009.
Have to remove the fuel tank from the vehicle to get to it. Not too hard, but would need to be able to lift and support vehicle high enough to remove tank.

Tiny
Jack42
Feb 25, 2009.
Is there any way to make sure that its not my injectors that are going bad rather than my fuel pump or are you pretty sure that the fuel pump is whats causing the problem? Its so weird because it runs good on the first gear shift when you first start it up and then after you start driving it for a minute it start accelerating roughly. It makes me wonder about the fuel pump because it never dies when accelerating, just pops like its not getting enough fuel. ERRRR UH ERRR UH UH UH ERRRRUH ERRRR. Thats how it accelerates if that makes sense to you. LOL

Tiny
JaredWilske6185
Mar 1, 2009.
When the injectors start going bad you get single cylinder misfires, not necessarily lacking overall performance. It probably cant hang with the volume/pressure needed to run the engine, that is why it fades when you get going, lack of volume/pressure

Tiny
Jack42
Mar 1, 2009.
Ok, last question for you. I have found some fuel pumps and they are around 200-300 dollars. Do I also need to replace my plastic tank or can I just replace the pump? I ony plan on having this car for 2 more years and I dont want to dump a bunch of money into it. I found this one for 75 dollars and I was wondering why it was so cheap.

Tiny
JaredWilske6185
Mar 4, 2009.

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