Hi all, new to the forums here.

I've got a 1999 Blazer 4x4 4 door with about 260K and no major maintenance related issues. I bought it from a signage company who serviced it fleet at the dealership it was originally sold at. It was mostly highway driven. I've upgraded the exhaust from the cat back when the cat blew out 19 months ago. I've got nology hotwires, platinum plugs and a K&N high flow air filter in the stock airbox.

For about a week now, off the line is sluggish to engage when it's been idling at a light for more than a few seconds. It bogs for 1.5 seconds at most then takes off.

For a few months, the transmission has been bouncing in and out of OD when on a slight incline cruising or when applying light to moderate acceleration on level. I assume that this may have to do with the previous owner's highway habits. I suspect this is the TCC locking and unlocking.

I replaced the fuel pump a few weeks ago after a short trip to the mountains when it was bogging badly under heavy acceleration on moderate inclines and altitudes. When replacing the fuel pump, I accidentally damaged the breather valve on the front of the tank but believe it's been repaired as the computer hasn't thrown any vapour canister or related codes.

All the fluids are at or within proper levels and it's not throwing any codes or going limp-home mode. I'm looking for suggestions or troubleshooting tips as I'm not crazy about R/R due to finances right now. Any ideas would be great.

Thanks!

 

Have you cleaned your MAF sensor? A dirty MAF can cause all sorts of problems, transmission included. The same can be true for a malfunctioning TPS sensor.

 

I did stumble across the other MAF thread and decided that would be a worthwhile try as it's a relatively cheap possible fix. And it made me think back to my cleaning of the K&N when I put an inordinate amount of extra oil into the filter.

So, figuring it could have been gummed up with a bunch of K&N oil, I headed to the grocery store and picked up some run of the mill 99% Isopropyl (I was too lazy and fearful of the tranny giving out to go as far as the hardware store for denatured).

I cleaned both the MAF (dirty, dirty, the vanes were all clogged and completely covered with carbon) and the housing (the whole thing was pretty bad looking) and now it looks like it just came out of OEM packaging.

MY GOD! I'LL BET IT DRIVES BETTER THAN NEW!!!

It's still a little sluggish off the line if you hit the brakes hard, but I think I've nailed that down to a leak in the vacuum system on the brakes (Just started the other day, you can hear a sucking noise if you hit the brakes harder than very gently.)

Being the third owner of this great vehicle (1st being the dealership for a year, then the sign company I bought it from) I've got all the maintenance records for it and it's been extremely solid. I'll own it 'till it rusts apart and then I'll probably still resurrect it with bondo or something.

Thanks for the suggestion! It was a great six-dollar-fix!

 

Glad it worked!