You are here:

Chevrolet Repair/fuel system

Advertisement


Question
QUESTION: I have a 1999 chevy blazer 4wd 4.3l 6-cylinder. When I first start the engine my rpm reads 900. As the engine gets warmer, the rpm drops down to normal idle speed. Why is this?

ANSWER: HI CHRISTOPHER, THIS IS NORMAL,WHEN THE ENGINE IS COLD THE COMPUTER WILL RAISE THE IDLE SO IT WILL NOT STALL OUT..IT PUTS MORE FUEL IN THE ENG BY ALLOWING THE INJECTOR PULSE TO STAY OPEN LONGER AND AT THE SAME TIME RAISES THE IDLE.. BEFORE FUEL INJECTION WE HAD CHOKES,THIS WOULD ALSO RAISE THE IDLE UNTILL THE OWNER HIT THE GAS AFTER IT WARMED UP AND THIS REMOVED THE CHOKE DROPPING THE IDLE....YOU SEE IF YOU START A COLD ENGINE UP AND THE IDLE IS NOT RAISED UP IT WILL STALL UNTILL IT GETS WARMED UP..THIS IS A GOOD FEATURE.. HOPE THIS HELPS YOU ,,TOM...

SORRY I FORGOT TO ASK YOU WHAT EVER HAPPENED WITH THE TRANSMISSION PROBLEM  ????

---------- FOLLOW-UP ----------

QUESTION: I have a 1999 Chevrolet blazer 4wd 4.3l 6-cylinder engine with code Po452 that was scanned by Autozone. It reads fuel pressure sensor low input, check connector and wiring and hose and fittings. The question is where is this sensor located and how to fix it?

Answer
HI CHRISTOPHER, THIS SENSOR IS ON TOP OF YOUR FUEL TANK. THE TANK WILL NEED TO COME DOWN TO GET AT THIS SENSOR...THEY DO GO BAD. CK THE WIRING TO THIS SENSOR ON TOP OF THE TANK AS WELL. I HAVE FOUND SOME CORRODED WIRING HARNESSES THERE AS WELL. GOOD LUCK TO YOU,,,TOM.....

Chevrolet Repair

All Answers


Answers by Expert:


Ask Experts

Volunteer


TOM SHEETS

Expertise

PLEASE READ ALL OF THIS BEFORE ASKING ANY QUESTIONS. IF THIS CHEVY SECTION IS MAXED OUT.YOU CAN REACH ME IN THE OLDS/BUICK SECTION. Will answer questions from 6:00am to 10:00pm all days [EST][[[ NO DIESEL OR PAINT QUESTIONS]]] will answer all 1965 to present QUESTIONS ON ALL GM'S on mechanics of these cars. Keep in mind i am not there in person i am going on what you are telling me !! PLEASE IF ASKING A QUESTION GIVE ME AS MUCH INFO AS POSSIBLE. THE MORE THE BETTER. SUCH AS YEAR,MAKE,MODEL,ENGINE SIZE. THIS WILL HELP ME HELP YOU. I will not be able to answer all questions because of some situations that i would really need to be there and see things for myself,such as electrical issues. In many cases i would need wiring diagrams. I can also give you an estimate on what the cost would be at our repair shop as an idea to help you. Keep in mind that my answer is ONLY MY ADVICE,ck with your mechanic as well.. >> THANK YOU, TOM..

Experience

I have been a ASE certified master mechanic for over 30 years and certified IN ALL 8 CATEGORIES,[engine repair,engine performance,auto trans,manual trans,clutches,steering and suspension,brakes,electrical systems,heating and air/cond. I am also a state CERTIFIED inspector for over 30 years. I do computer work [pcm]fault codes,pcm flashing,state inspection monitor readiness,repairs on exhaust,fuel service,[injection and carburetor,] charging system problems, running issues,alignments,frame problems,tire balance,struts and of course standard and anti-lock brakes.

Organizations
nys state auto repair industry and ase group.

Publications
N/A

Education/Credentials
high school,4 years of tech school,and many many hours of auto training with many gm classes and aftermarket training classes..

Awards and Honors
ASE MASTER TECH CERTIFIED IN ALL 8 CATEGORIES.NYS INSP LICENSE AND A/C CERTIFIED

Past/Present Clients
MANY CUSTOMERS IN OUR BUSY SHOP.

©2016 About.com. All rights reserved.