2000 4.3 Blazer
She is sluggish, and very hesitant. Backfireing through the intake sometimes but not always.
The converter was tested and is fine, EGR is kept clean, Tune up last year made it idle smoth, but didnt fix the problem.
The gas guage quit shortly after I bought it, I kept up with the milage so I wouldn't run out. But my wife drove it for a week about 3 years ago and ran it out. The issue seemed to start from there, and has gotten worse. Do you guys think it could be something else? Cause I really don't wanna dive in that fuel tank haha.
I know I need to have the pressure checked, I just hate to pay someone to do it cause my money is limited at the moment.. Is there a way I can do this myself?

Thanks for reading!

 

id do a fuel pressure test to diagnose the problem

heres a link that shows you how to diagnose it

https://blazerforum.com/forum/tech-a...agnosis-23038/

you can always go to a local auto parts and see if they lend fuel pressure gauges or just buy one there so worth having

 

Thanks for the reply, I just printed everything on the link including the picture and PDF format looking pages. I'll probably read over this several times tonight and try to paste it in my mind.
My wife is driving home from a baby shower tonight and she called a little while ago and said it wouldn't make it up the driveway. I had her put it in 4L to use the tourqe to get out.. pathetic huh?
I assume number 7 on that diagram of the engine is where I would check the pressure.
Thanks again man!

 

xgiovannix,

I took it to a mechanic that a friend of mine knows well, and we checked the pressure.
We turned on the switch, the needle jumped fast to about 63psi and held.
He had me crank the engine, and it came down to 58-59 at idle. Gave it gas and the needle went up as far as 65 and back to 59 when the RPM rested at idle.
Even when the engine was popping and starting to act up a little at low RPM, it didn't change the fuel pressure.
We killed the power, and waited about 10 minutes, the needle just barely went down not even one psi in that time.

The Mechanic said it was performing as it should.
After telling him about the converter and EGR, he said it may be one of these: Computer, Spider Injectors, TP Sensor.
I left without asking him, but wouldn't the TP Sensor spit a code at me?

 

New symptom...Well, old but I just never noticed it:

I played around with it some today and noticed that when sitting still in park/neutral. If you jab the gas petal, it pops and starts acting up really bad. If you gradualy give it gas/rev however, it doesn't do it hardly at all.. The thing is, is that if your climbing a hill at even a good speed of 55mph, if I push on the gas more it actually will slow down. So I'm better off just holding what throttle I do have and creeping up the hill.
I'm stumped, I just hate to take it to the stupid dealer..

Thanks for any suggestion's, I'm taking any advice I get very seriously.

 

TPS should throw a code, but it's possible it won't..... anything is possible. Look in the DIY's for TPS testing procedure. Basically you hook an ohmeter to it and check resistance across the throttle range. It's easy to do if you know what to look for.

Could be MAF as well....have you cleaned/tested the MAF?

 

Thanks for the input!

The MAF is clean, and seems to be doing what it should. I took off the K&N intake today to see if maybe I could get lucky and spot something stupid in the throttle body, and the engine nearly cut off when I removed it. Then I remember reading on here to remove it before cranking the engine.

There looked to be a fair amount of carbon build up inside the throttle body, not sure if all that is normal or not.

Thanks for the tip about the DIY threads. I'm gonna go there now and check it out.

Thanks again!

 

Throttle body buildup is normal. Egr dumps right under it (on my 98 it does at least). it's possible that you've got a significant amount of buildup in your intake but for it to be THAT bad would take a LOT. Plus i don't think it would be a (warm only) issue.

Did you recently (just before the problem started maybe) clean and oil your K&N filter? If you did and you accidently over oiled it it's possible the MAF is getting fouled with oil coming off the filter.

 

funny you mention that about over oiling the intake filter, cause I thought about that erlier today. I haven't cleaned it in a while, but the last time I did, I know I over oiled it. Perhaps it is the MAF and I just cant see it, cause it looks real clean. However, I know next to nothing about a MAF. I'm not sure how sensitive they are or anything like that. Perhaps I should clean it and see what it does.. Is there a cleaner you recomend?

 

that stuff right thurr will work.