02 sensors in 1993 K1500 blazer, full size
Hey, good morning everyone!!
My boy loses acceleration while I'm, driving.
About 30 mph, for about a minute, then it just goes down
It floats and when I think it's ready, I gas it
sometimes it's ready, sometimes it's not
Ihad the exhaust leaks fixed and new muffler
Is anyone familiar with this?
Thanks

 

Ironically, I am familiar with this.. clogged catalytic converter.

I found mine was clogged after I fixed my exhaust leaks between the manifolds and Y-pipe (original manifolds had broken/missing studs). I replaced my manifolds and had your symptoms on my test drives, and then it got _really_ bad after a few days. When it got bad, I barely made it back to my farm in 1st gear and my spark plug wires caught fire after I parked (where I didn't have a heat shield in place...)


Another possibility is a broken choke inside the air cleaner housing (pop the snorkel off to look inside). (I think your 93 has a choke???). I removed my choke altogether because I was missing parts when I bought the truck.

I assume your air filter and fuel filter have been replaced recently.

 

Everything but the fuel filter
I got the exhaust leaks fixed. Catylic converter fine, and new muffler
I forgot about the fuel filter
I went to get it fixed, and my mechanic was without it
And I forgot to go back, so I will call them to see if t's been ordered.
Thanks Helo

 

Any parts store should have the fuel filter you need for a few bucks.

I wouldn't be so quick to say the cat is good, since your problem started or got worse after the exhaust leaks were fixed, right?? If it's even slightly restricted, that's likely your problem. Especially if it's the original cat!

Check the TPS voltages. The reference wire is 5v, and the dark blue signal wire should be .5-1v throttle closed and 4-5v WOT (engine off, ignition on). Should be smooth with no voltage spikes or drops as you rotate the throttle.

EDIT- You might pull your ignition control module and have a parts store bench test it a few times [5-10] until it's hot. It's maybe $30 for a new one.

Last time you did Cap/rotor/plugs/pcv?

The fullsize board is eerily quiet.. fullsizechevy.com has a bunch of guys with the older trucks FYI.

 

Here's a thought: MAP sensor?

https://blazerforum.com/forum/archiv...hp/t-3783.html