I have a 2000 chevy blazer zr2 and ive replaced fuel pump spark plugs and wires but in the morning the cold motor acts like its missing runs very sluggish unless I stomp on the gas what could it be? Also the check valve ear the. Passenger side of firewall is a T and one hose has a screw in it I need help if pics are needed I will post

 

Does the check engine light come on when you turn the ignition to the run position, (engine off)? Does it turn off after the engine is running? If it stays on, we need to know what trouble codes are stored in memory.


Fuel pump and spark plugs need to be AC Delco, aftermarket stuff causes problems with these vehicles every time. Have you replaced the distributor cap & rotor? Also needs to be AC Delco.


Have you checked fuel pressure and leakdown? If so, what were the readings? When was the fuel filter last replaced?


Need some pictures, both distant and close up, so we can get a perspective of where the vacuum lines are located.

 

Spark plugs are what it calls for plugs and all are ac delco not sure when fuel filter. Was replaced but tank was beautiful when I replaced fuel pump when the motor is warm it runs great maybe a little hesitant but not to noticable distributor cap was replaced a year ago but again I found a small collapsed vacuum line I clipped and plugged back in
That connects to the T check valve... but on the T check valve one hose comes off the T about 2 inches and. Is plugged with a screw the only codes being thrown are catylist since the Cadillac converter was removed and abs moduel bad

 

Have you checked fuel pressure and leakdown? If so, what were the readings?


Need some pictures, both distant and close up, so we can get a perspective of where the vacuum lines are located.

 

I have no idea of pressure orleakedown but what would that have to do with once the motor warms up it drives great only on a cold motor does is have a bad hesitation and I will upload pics during the daylight tomorrow

 

A cold engine requires more fuel pressure and volume than a warm engine. Correct pressure and acceptable leakdown rates are critical on this engine, they must be within specs. Neither one is monitored by the OBDII system, so it can't/won't set a DTC in memory. It needs to be checked whenever there is a driveability issue. It's easy and quick to test it.


https://blazerforum.com/forum/2nd-ge...eakdown-88305/

 

OK. Think youill check that tomorrow morning as well with the pictures