someone told me it was a sensor, had the plugs wires erg valve replace still having issues any ideas[sm=feedback.gif]

 

details!!!!!

 

yes we definitely need more details. Does it just feel down on power while you accelerate or is it skipping (hesitating) during steady driving, etc??? We also need to know what you are driving (year, motor, etc.).

I just fixed a hesitation/power-loss problem in my Bravada. It turned out to be a VERY dirty Mass Air Flow (MAF) sensor. If you have the newer vortec 4.3L (I'm not sure if this applies for older 4.3Ls as well), the MAF sensor is directly after the air filter box. To clean it, you must remove the 4 screws that hold the aluminum pieces to the sensor. Then take some carb/throttlebody cleaner and spray the crap out of all of the metal exposed in the MAF sensor, making sure to NOT touch the thin wires with anything but the stream from the can. This completely fixed my power-loss problem that has baffled me for a long time.

The MAF sensor can gunk up very easily if you have a K&N filter installed. The oil from the filter coats these small wires and the sensor doesn't read correctly. If the filter is oiled properly, you shouldn't have a problem, but K&N had a problem with over oiling out of the box and that caused GM to have a Technical Service Bulletin (TSB) about aftermarket oiled air filters on all of their vehicles and the driveability concerns that may arrise due to over oiling.

So, give us more information. If you aren't getting any misfire codes, then give the MAF a good cleaning. Heck, clean the MAF anyway and see what that does for you. But BE VERY CAREFUL because the MAF sensor is NOT CHEAP!!!

 

Hello, I am also having a missing problem with my 4.3L.

Vehicle Details: '97 Blazer 4.3L, 4x4, 105K
Symptoms: On heavy up-hill pulls get occasional mis-fires. Under continued hig load, you get a huge power loss with hi RPM's and continuous mis-fires. Service engine soon light comes on and will go off after a combination of 5-6 starts and 2 -3 hours of operation. Was once told there was a residual Mis-fire on cyl 6 code when the computer was read when n the garage for an other issue.
Steps taken so far: Replaced plugs, wires. Air cleaner is new.

Recommended next steps for replacement or does it make more sense to get it diagnosed by someone with the equipment?

Thanks

 

Having the same problem with my 89 chevy s-10 blazer. I am thinking I could try the same solution to mine also? I have a K&N air filter and it does exactly swartlkk said.

Where about is mine at? Couldn't find anything in my repair manual about the MAS.

 

Next things I would recommend changing would be the cap and rotor. My Bravada has 74k miles on it. When I removed the cap to inspect it, there were carbon trails all over the place inside as well as having the center electrode worn flat. This was causing a vast majority of my misfires. The carbon trails inside the cap lead the spark away from the wire-plug and to ground on the metal distributor body. Normally a carbon'd or cracked cap will generate more misfires on humid/rainy days than on dry days. This is because the humidity of the air aids in the spark travelling where it doesn't belong.

Tittlebitties... I'm not sure if you have a MAF sensor on an 89... If you do, it would have to be in the intake path somewhere and is generally before the throttle body. I really don't think that you have one because if I remember correctly, you have a round air cleaner housing and throttle body injection. I'm not sure what that system uses to provide the proper fuel. In your case, I would remove and inspect the cap & rotor to see if it needs replacement. If it looks ok (clean contacts and no noticeable carbon trails), report back and I'll see whatelse I can come up with.

 

Yeah I figured I didn't since I couldn't find it in my Repair Manual.

Looked at the cap and rotor :|. My dad and this other dude were surprised that my blazer even ran lol. Got that all fixed and took it for a drive and it didn't pulse like it was. Went home and it started again. It like doesn't do it all the time. I think it does it when I first start to drive but not to sure. I will check more closely tomorrow.

So what else could it be? If it only does it for a bit when its been sitting for a bit and then I go then it might be cause its not warmed up or something.