I've got a 94 full size blazer 5.7 350 v8, NV4500 manual tranny, headers, 2.5 inch pipes and race mufflers. The thing was running great but now is running rough. I havent done anything recently to it, so I know it's not a screw up that I caused by improperly fixing it.


Today I drained and replaced the tranny fluid and its running better. It has a little hesitation here and there and then seems to "kick in" and speed up. Plenty of power, I just pulled another full size blazer around today in 2wd without a problem. However at the top end in 4th and 5th, I find there's not much power until it's at 2500+ rpm. In 5th, it loses power when its under 70mph and going uphill.

I'm thinking transfer case fluid and rear diff fluid tomorrow. I have to do them anyways, havent been done in year and I like to keep on these. What fluids are you guys using for these parts? Anything else I should change the fluid on that I may have missed? This blazer is new to me as of 6 months ago and I've been going through part by part lately to make sure everything runs well.

 

i would start with a complete tune up

 

Change the fuel filter recently?

 

just did a complete tuneup and it's running fine again. I had it at a vocational school being worked on for numerous things when I didnt have the time to work on it. They gapped the plugs between 38 and 45 instead of the 35 it requires. Awesome job lol.

Thanks for the help guys.