Sluggish Acceleration

[brentb08]

My '02 Blazer is sluggish at times when I try to accelerate quickly. It takes off pretty well, but it feels like it bogs down between 25 and 30 mph and just doesn't seem like it has the power a Vortec V6 should have. It also feels sluggish when going up hills. It is really bad when the A/C is on. The engine temp even got pretty hot yesterday when I was running the A/C. I have also experienced a delay in acceleration when taking off from a stop...not all the time, but some times.

[taillight]

Tune-up? fuel pressure?

[brentb08]

Not had a tune up lately. What about the fuel pressure? How do I check that? I did have the fuel filter replaced 2 weeks ago.

[MT-2500]

Originally Posted by brentb08

Not had a tune up lately. What about the fuel pressure? How do I check that? I did have the fuel filter replaced 2 weeks ago.

4.3 V6 ?
Any Hard to start cold ?.
There is a fuel pressure test port on rear of fuel rail.
You will need a fuel pressure gauge.
Rent borrow or buy one.
Some parts places will rent them to you.
Check cold start fuel pressure.
Check engine running fuel pressure.
Check engine running on the road fuel pressure.
Then shut it off and watch for fast leak down.
Pinch off at rubber part or block off return line and check full pressure.
Later V6 and V8 gm engines should have 60-66 fuel pressure.
Cold start should be 64-65 lbs of pressure.
If you do not have full fuel pressure on a cold start the injectors will not squirt fuel.
Do not leave home without it.
Engine running should be 60-66 lbs pressure depending on engine load.
Full pressure with return pinched off should be 75-85 or more.
And if it has a fast leak down after shut off you have a leak.
Post back fuel pressure readings.

Also check engine vacuum at idle and at 2K and post back readings?

[brentb08]

Yes, 4.3 V6

No, it is not hard to start cold. It starts right up. I was out of town and it set for 3 days and when I started it, it started right up.

If the pressure is low it means there is a leak somewhere? That will cause it to be sluggish?

Do I need my mechanic to check my engine vacuum? I know that on a '94 Explorer I had, a vacuum hose was loose it caused the engine to be a bit on the sluggish side.

[MT-2500]

Originally Posted by brentb08

Yes, 4.3 V6

No, it is not hard to start cold. It starts right up. I was out of town and it set for 3 days and when I started it, it started right up.

If the pressure is low it means there is a leak somewhere? That will cause it to be sluggish?

Do I need my mechanic to check my engine vacuum? I know that on a '94 Explorer I had, a vacuum hose was loose it caused the engine to be a bit on the sluggish side.

Even if not hard to start cold you need to run the full fuel pressure test.
Low pressure does not always mean a leak or bad fuel pump.

The engine vacuum test /gauge is a cheap fast test for restricted exhuast and other engine running problems.
It picks up on late timing and engine miss low vacuum bad valve and restricted exhaust just by reading and watching the gauge.

Vacuum gauge is about 10 USA $ and you can test the engine vacuum yourself.
Ever DIY and mechanic/tech should have one and learn how to us it.
It will tell you many things about the engine running conditions.

Have you noitced any check engine lights or flashing check engine lights.
A flashing/blinking check engine light points to a engine miss.
MT