94 s-10 blazer 4.3 cpi loss of power, no brakes

This is a vacuum leak causing the oxygen sensors to throw codes or its both sensors or you have an exhaust leak before the sensorsyou say you changed the intake manifold gasket did you change upper plenum and the lower intake or just the top? Ok let's try this take fuel injection cleaner and spray around the intake upper and lower while in drive foot on the brake if the idle changes the leak is there do the same for all vacuum lines

You have a bad vacuum booster. The diaphragm in the booster is ruptured resulting in vacuum loss and no power assist to the brakes. Do not drive in this condition, loss of control (stopping) hazard exist.. Replace Power Brake Booster. Since replacement of the booster requires removal of the master cylinder, replace the master cylinder as well, It is old (2003) and time for replacement

Hi there:On 1995 CHEVROLET TRUCK BLAZER 4.3L CPI 6CYL check this...



Fig. 30: Engine vacuum schematic - 1995 4.3L (VIN Z) engines



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I HAD A BLAZER WITH THE SAME SYMPTOMS REPLACED THE TRANSFER CASE MOTOR AND SOLVED PROBLEM. TRANSFER CASE MOTOR SHIFTS FROM HIGH TO LOW GEAR IN THE TRANSFER CASE AND TELLS THE FRONT ACTUATORS TO INGAGE FRONT HUBS . MOTOR WON'T MOVE TO 4 HIGH AND GRINDS WHEN TRYING TO MOVE TO 4 LOW, TRANSFER CASE MOTOR FAILING . CHECK VACUUM LINES AND ACTUATORS ON FRONT DIFF THEY FAIL, CAN CHANGE TO CABLE ENGAGEMENT INSTEAD OF FAILURE PRONE VACUUM ACTUATORS.

Check the fuel pressure regulator and the EGR valve, I would check the fuel pressure regulator first and go from there. Good luck and keep me posted. Not sure what the pressure should be but thinking it's 62 to 65 PSI upon start up and should drop 5 PSI when engine running, check the vacuum line to the regulator.

There is three vacuum line on the driver side, top of the transfer case. One comes from the engine, 2nd line goes to the breather vent, 3rd goes to the 4x4 actuator diaphragm. The 4x4 actuator is located under the battery tray, check the vacuum line and listed for any vacuum leaks at the acuator. Inspect the cable from the actuator to the front differential (pumpkin), it's common for the cable clip on the pumpkin to corrode and will need to be replaced. Good luck and keep me posted.

leaky rear break cylinder or master cylinder

Try starting the vehicle , place the emergency brake on , switch from drive to nuetral. with engine running try to move the 4wd handle. If your handle moves in and out of 4 wheel drive and the selector handle moves into 2wd you need to drive the vehicle to get it out of 4 wheel low otherwise the 4 wheel drive solenoid may be stuck . This is located on the front axle . round with a vacuum line coming off it. Check the vacuum line at the solenoid or it may be the solenoid. Gook luck with your fix

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then you will need a master cylinder or a brake booster

sounds like your problem is your injector there is a cap on your upper intake that comes off pull it off take a flash lightlook down into the intake if it's got gas in it thats your problem. good luck Phil.