85 s10 blazer california emisions...runs great cold but once hot loses a lot of power and stumbles to the point 4 and 5th gear r almost usless, can barley go 55mph on a flat surface. Its weird cuz it idles great and engine runs very good, I can barley tell its running at idle. But once it as it warms up I lose power and It won't make the thing go .

 

It sounds like you could have a clogged catalytic converter. When you are experiencing the lack of power, is it more related to the RPM? A clogged cat will limit the RPM the engine can run out to and will be worse under load.

 

Right that's what I thought too at first till I cut it out and so cat convert is none exsistant..lol....

 

Hardly CA emissions then...

How about you run down through what you have done to try to eliminate this condition so people do not recommend things which have already been done and not communicated...

 

kk im not worried bout emissions im moving out of cali..so we got new fuel pump, water pump, carb, 02 sensor, cap and rotor, msd ignotion, msd super coil 3, msd wires, ignition modul, magnetic pick up...thats everything. oh and i am getting a code 34 map sensor

well still having problems with the truck under load and higher rpms...all the stuff ive done the only real thing left is newer plug wires maybe regapping plugs to .040 instead of .045, ummm and ive herd alot about the fuel sock in the those blazers tend to clog and have just rust all over em..sooo i guess im dropping the fuel tank next to check it out...

well dropped the fuel tank, sock is clean.....i wish it was clogged....well gotta put tank back up and back to the drawing board...anyone have any other suggestions?

 

Is it a mechanical or electric pump?

Have you cleaned/rebuilt the carb?

 

i listed up top new fuel pump and new carb....and the pump is mechanical.

 

Was the carb properly adjusted? Was it a stock replacement? Your truck likely came with the E2SE carb which, even when new, was a royal pain to get adjusted properly.

What have you done to troubleshoot the MAP sensor problem?

 

yes its a e2se carb brand new i just bolted it on..and as far as the map senser i havent done nothing i dont even kno where the map senser is.

 

Hate to sound over simple, but I don`t see any mention of the regular fuel filter being replaced. Low power at high rpm/high gear is classic example.