I just picked up a 2002 blazer with 130k a few weeks ago, my friend has a 2001 blazer xtreme and he seems to have way better off the line power, pep, response out of his blazer with the stock CPSI and 200k miles and his seems to work way better as a towing rig; aware that multiport doesn't increase performance at all but orignial spider with 200k and still running good, no clogs or minimal on his part and mine brand new MPI spider. I understand I have 4 wheel drive and am about 400 pounds heavier,

The only conclusion I've been able to come up with is a lot of torque is lost through the transfer case or I have lower compression in one or more cylinders.

I only tow a small fiberglass tri-haul 15 foot boat and a 2 place snowmobile trailer but the truck seemed like it was struggling a little bit to pull the boat and he pulls it no problem with the xtreme.

Mine seems like it has a decent power band but you have to get into it a little especially on the freeway even without a load, I figured I should be able to feather it to keep up to highway speeds, it seems like something is wrong with it. I am not trying to beat on the thing but for testing purposes I tried doing a brake stand and couldnt brake the tires loose, I had a hard time spinning the wheels. It seems like when I stomp on it there is like a 1.5 second delay, Should I be able to break the tires loose easily with a stock 2002 blazer 4x4 running in excellent condition? The truck could be perfectly normal and I could just be paranoid, that is why I came on here to ask blazer owners alike.

I have done many things to the truck,
new fuel pump, fuel filter, multiport spider, cap, rotor, plug wires, maf and the P.O. said a lot of the other sensors were replaced. Tech 2 says cam retard is at 0 degrees.

I ordered a CAI and thinking about a throttle body spacer for a little more power while towing. Are there any differences between the xtreme and my blazer; we figured this much.

Blazer and Blazer Xtreme share these properties, Engine Vin W, Transmission 4L60-E (different tail shafts because of 2x4 and 4x4), 3.42 rear gears. Suspensions obviously differ. other than that what could be different, he drove my truck and said it should have more power, grant it is a 4x4 and it will loose some but not that much?

The previous owner said he did a tuneup recently but the plugs look a little rusty so I am going to perform a compression check on all of the cylinders when I swap the plugs anyway.

Transmission is great, fluid is good, shifting is excellent.

Sprayed the motor down around all seals with carb cleaner and no increase in idle.

My 2000 Jimmy always reads anywhere from 40 psi - 65psi.

Oil pressure reads low around 5 at idle sometimes and only goes to about 35 on the freeway, I read elsewhere on this site the gauge is junk and buy a mechanical guage if you want an accurate reading.

No lifter clang, well I hear a noise and think its the assessory drive I dont think its the lifters but I still plan on pulling the serpentine belt off of the crank for a better listening experience.

What brand of cap/rotor did you use? These trucks can be somewhat picky when it comes to plugs, cap, & rotor.

Also, is the tire size the same? Likely not and that can have an impact on acceleration, all else being equal, as it will change the effective final gear ratio.

I would continue with your next idea, pulling the plugs & running a compression check. That will likely tell the tale.

Another idea would be to go over everything else in the drivetrain to make sure that there is nothing dragging or out of alignment. Things like having the front axle engaged all the time, brake calipers sticking, clogged/restricted brake flex lines not allowing the calipers to release, etc can all make the truck seem slower than it really is.

There are much better things to spend your money on than a throttle body spacer as well. :icon_wink:

+1, if you really want the full potential from the 4.3 then get your pcm tuned. I got mine from blackbear and it was a night and day difference.

I pulled the serp belt and hear a little bit of a knocking, nothing too clanky or bad, im going to replace the crank bearings.

I think it was a wells, I bought it about 6 months ago for my 00 jimmy and swapped it over.

Just spoke with a friend that has been a tech at gm for a long time and metioned that he seen a lot of blazers with cam bearing failures after the intake gasket failed.

the p.o. overheated the motor but had the whole top end rebuilt he said, my buddy said they probably didn't touch the cam journals and to check for oil pressure with a mechanical gauge from the bottom of the motor at the oil filter and the top of the motor from the sending unit port.

I did not know this but Googling '2001 Chevy Blazer Extreme', your buddies Blazer has a 5 speed manual.

You have an automatic with 4wd.

I didn't even know GM sold a 2nd Gen S-10 with a stick. That's why your Buddy kicks your rear at launch. I bet money he also has a better rear axle gear ratio since he has a Manual Tranny.

Buy your buddies S-10. You'll never get your Auto S-10 to match his take off. He has Gear Superiority in Gear Ratios. My wife had a 2002 4wd Blazer and we towed a car Coast to Coast across America and we couldn't even tell we were pulling anything. Tons of power. Took 4 gas tanks to cross each State. :(

He does not have a manual trans, same 4l60e as I stated above, also he has the same rear gear ratio minus the transfer case, I checked his rpo codes, I installed acdelco plugs and wires over the previous taylor wires and autolite plugs and it made plenty of difference. My tech 2 was showing no misfires before I changed the plugs and wires but I did because I usually only use oem. I never checked oil pressure, it is running great now and I think the oil pressure is probably faulty guages. Just got back from a 500 mile run up north and it is running great. I could probably pull on my buddies xtreme now after everything I have done (new parts) but racing blazers would just be moronic unless a LSx block was dropped in or a typhoon/syclone engine.

I have a manual and its got the 3.42 gear ratio, I don't think it has very good take off speeds.

Have you checked your exhaust and cat. Converter?
If one of them is clogged you will loose power.
I have had a clogged cat. on my 305 tbi in my caprice and it felt like i lost half of the original power.

post up, truck runs great now.

I used my infrared temp gun, fuel trim and o2 readings to diagnose the cat good.

What did the trick, or was it good as it was?