I have had bad acceleration on my 2000 chevy blazer LT, it's 2wd 4dr, with 188,500 miles on it. I just recently did ton of work on it, but still doesn't seen to acceleration as i was expecting. i just did the following maintences things I replaced last month or earlier-
Oil change- i have used 5w 30 full syn MOBIL one for years
fuel filter
transmission drop pan and flush
spark plugs and new wires
new pcv valve and new pcv elbow fitting
new mass air flow sensor
new distr cap and rotor
complete new raditor with all new hoses- old one cranked
cleaned egr valve today, and put in new gasket.
i seaformed engine and fuel system, plus run in through the brake booster.
Not sure what else can be done, it runs, but not as great as i would like, i also have a power spacer in it, with k&n air intake, plus i have it hypertech power programmer in it also, which lets me run a colder temorsat 160 instead of 195. It shakes a little when i stop, and just doesn't have that kick of acceleration it use to have, it also has hard starts in the morning at times when it sits for over 5-6 hours. I was thinking it could may be my fuel pressure regualtor, and one of my injectors are clogged, but not to sure of how to properly unclogged an injector, or properly diagous if an injector is really clogged. any advice would be great thxs.

Any advice would be great! I also have JBL headers

thxs guys

 

Nobody has any in put, so have i just done all I can do for now, i cleaned out my throttle body today, didnt remove it from engine little advance for me to figure out but i clean alot carbon inside of with with toothbrush, and am planning on cleaning iac valve tommorow.

 

You dont mention codes so I assume there are none. The power programmer would be the first place I would look. Do you have any way to do a live data stream? At that milage personally i would be trying to get my truck to be more reliable instead of trying to get max performance out of it. Have you checked fuel pressure?

 

No I haven't tested fuel pressure, I will do that next. I agree am not trying to max out engine anyone, I just want it to run smooth without hard starts and slow accerlation, with high idle. I have kept it up reg with all maintance since I bought it from my dad 110,000 miles ago. I am just wanted it to last other 100,000 miles or more.

 

I would test fuel pressure next. But one thing that might not show up would be poppet nozzles that are sticking and/or just not spraying properly. This is a known issue with the CPI & SCFI engines. GM released a new spider that moved the electronic injectors from the central injector housing out to the intake runners, eliminating the pressure actuated poppet nozzles. This removed the problems associated with the poppets. Run a search for "MFI+upgrade" without the quotes and you should find more than enough information.

 

Thanks SWARTLKK you seem to have great knowledge of engines, as myself not as much. Ill look into the info you gave me, and keep everyone updated. thanks again.

 

Another thought. The cooler temp youre running your engine at.....Educate me what the power gizmo is doing to allow you to run cooler engine temps. Is it tricking the engine into thinking its warmer than it actually is? I had a truck that wouldnt start at all if the air intake sensor was disconnected. just curious.

 

My opinion is to ditch the 160F t-stat and run a minimum of a 180F if you want to, but there isn't much of anything to be gained by doing so. At least not on these engines. See if that impacts the sluggish nature of your truck.

The Hypertech programmer should lower the minimum temperature for closed loop operation and fuel enrichment mode in the PCM. No tricking of sensors, just lowering the threshold where closed loop operation and fuel enrichment mode start/stop. But that doesn't mean that it is going to run optimally given the lower engine temperatures.

 

Thats what I hear also SWARTLKK, I have am guessing an older Hypertech Prower programmer I purchased when the first one can out. It explians that lowering thermostat produces a cooler, dense intake charge the helps produce more power, plus it adjusts the operations of electic cooling fan. Not sure if it did whole lot change in my blazer, Ive had the program in it for couple years now. The only thing I didn't adjust was the fuel option for high octone programming gas to high now a days.

 

My personal humble opinion....Snake oil. Take it back to original.