I have a 1997 blazer 4x4, earlier today I filled the tank up with good gas.. took it for a little drive and went home. The drive went fine and it was running great. I went home and cleaned it out and went to go to a friends house and this problem has suddenly come up, When I press the gas the engine bogs down and does nothing. not stall but bogs out, if I very very lightly press the pedal the truck while rev up to high rpms but sounds weaker, almost higher pitch than usual. You can still drive it but not at freeway speeds 45, 50 tops after 2 rpms the truck gets quiet and does nothing. A couple times It did respond to the pedal but it was stuck at the speed I was going and just revving up. This is my second blazer and the last one I had did this EXACT same thing. When I had a diagnostic done it said is was the O2 sensors, but the check engine light isn't even on in this. I'm really worried becuase I had to junk the last one after chasing ghost forever, any help would be GREATLY appreciated

 

change out the gas filter, even though you may think you got good gas, you may have gotten gas at a gas station that just had a delivery and all the junk in their tank was flaoting around and it got sucked int your tank, a gas filter is roughly $10 , cheapest thing i could think of right away to try and help fix it. if you df decide to change out the filter, when you take the old one out shake the filter to see if theres any rattling inside, i actually had a FRAM filter come apart inside.. I cut it open carefully with a hacksaw and the insides were all moving around..good luck and let us know what happens.

 

Thanks for the tip, after reading around a bit on here I'm suspecting multiple things, I guess theres a ground that could be causing allot of the quirks the truck has, I'm going to try changing the filter and checking that ground wire tomorrow (if weather permits) I'm really hoping this is a easy fix, I can't afford to put anymore money into this car. Next on the list after that is MAF and MAP sensors I guess, and from what I hear maybe the CAT? but I'm not sure.. It does rattle in the CAT but would that cause the engine to bog down do you know?

 

Please dont start guessing what is wrong and just installing parts without knowing they are actually bad!

Are there any codes? Do you have access to a scan tool that has live data capabilities? If not, I would buy one. Its cheaper than buying all the parts you just listed that youre planning to replace!

Logically troubleshoot the problem...dont guss...guessing is EXPENSIVE!

 

It's odd, I don't have a scanning tool. But earlier today the MAF sensor came up, Last week I got a EVAP code. I went back to Autozone and had the rescan it before I bought the sensor and the code was gone. theres no check engine light either, but the car will hardly run. The check engine light won't come on at all so i never really know when its throwing a code. I've been looking at a 50 dollar scanner from autozone but I don't know if it will do what I need it too

 

Dont get it from autozone. I dont like their scanners. I have one...I dont use it. I got a $150 from walmart online. It does the live data scan. Many codes wont pop up instantly. The computer need to see the failure several times under certian driving conditions to set many of the codes.

Be sure to use the DTC troubleshooting charts like that a certian generous individual put up on this forum. He saved me hundreds of dollars and many hours by making this info available! When you pull a code, go through the chart. There are several MAF and MAP sensor codes that mean several things. I wont get too detailed, but one sensor was setting codes for a different sensor. It was practically killing the truck and I had a bazillion codes. Only way I found it was with a live data scanning tool and the DTC troubleshooting charts he provided! I really really urge you to get the live data scanner. You will see exactly what the computer sees!

Good Luck!

 

CarMD.com I have one , have used it, and i think it works GR8..

 

When you say "The check engine light won't come on at all..." does that include when the key passes through the RUN position when starting (i.e. are you sure the bulb works)?
O'Reillys (where I live at least) will loan code readers so that you can get one for a weekend and not have to run back to the store every time you try a fix. (Requires a deposit but I just "put it on the card".)

 

Yes, for some reason just before I went for a Echeck last month the check engine light stopped coming on even in the run position when starting, I'd think it was a bulb but it was on.. I took the battery out one day, put it back in and it went off and has never been seen since.. but you can still pick up codes once in awhile, sometimes I stop in autozone or advanced auto parts and scan it, usually its a evap code that comes up or a shift solenoid.. or nothing at all.. but right now the truck won't even do 45 and it's not reading any codes.. I find that odd, I did go out and buy a multimeter today to see if I can start trouble shooting sensors. but the directions on it suck, and it said I'd have access to this site called repairpaith on it but I can't seem to find the promo code so I can see the wiring schematics.. I'm also learning I need a vacuum and propane torch to test the things I want. Just my luck, anyone have any suggestions on where I can see schematics? maybe an online service manual? free if at all possible.. although I'm about ready to break down and pay for a subscription, money is tighttt. I'm just trying to single out what this could be, right now it seems like everything is wrong! but I know it's probably just one pesky thing makin my blazer go nuts

EDIT Also when I say it wont to over 45, it's nothing transmission related, for some reason the engine will not allow itself over 1.5, 2 rpms without bogging down, its like it's starving for air or gas, I replaced the fuel filter today as well with no change at all. although the filter had black gas in it and was almost rusted threw.. real bummer too I was excited to see how dirty it was thinking MAYBE just MAYBE..but now I'm back at square one

 

Get a fuel pressure gauge and check it. It should be only 50 when you turn key on. It needs to hold that pressure for 10 min. If it leaks down Replace your nut kit or fuel regulator under your plenum.