Engine code 61 help

[Johnny5]

Hey guys so i replaced my injectors, coil packa, wires and a few upgrades but the secondaries arent kicking in. I thought it may be the 2nd fuel pump but i pulled code 61 yesterday which the manual states is either vacuum pump or the vacuum transduser (provides signal to computer). Its hesitating when given heavier throttle and revving slowly. Anyone have experience with this?

[Johnny5]

Or know where the vacuum transducer is? ( not sure if i spelled that right)

[XfireZ51]

The secondary or differential MAP sensor provides a signal to the ECM for adequate vacuum. It's located under the ECM and has a vacuum hose and harness connector on it. If it signals to the ECM that there isn't enough vacuum, the ECM WILL NOT open the secondaries. Now WHY there isn't enough vacuum is another matter.
94-95 motors has sensor under plenum.

[Johnny5]

I am going to see if thr vacuum hose is connected and getting pressure.

[secondchance]

Code 61 is;
61 Secondary Port Throttle System Error

My experience when the differential MAP sensor failed code 56 was thrown. I would check if the secondary fuel pump was working.

[Coupe89]

I just replaced a check valve under the plenum.

I wasn't hold vacuum.

I put installed a t and gauge over by the map sensor.
I was the gauge take vacuum. Then the vacuum discharged. Only held for 2-3 seconds.

[Johnny5]

Hey Young, yea i thought it was the 2nd fuel pump as well than i read that code with a paper clip. I have to test the fuel pumps. Its been 3 months Ive been waiting and I still have yet to feel the LT5 at full power

[secondchance]

Originally Posted by Johnny5

Hey Young, yea i thought it was the 2nd fuel pump as well than i read that code with a paper clip. I have to test the fuel pumps. Its been 3 months Ive been waiting and I still have yet to feel the LT5 at full power

Don't feel too bad. It took me years to figure out I had injector issue.

[Johnny5]

I think this was a false code. It came on for a second than disapeared. I checked the sensor with my father. took it out, hooked up a hose and sucked into it...normal operating range with the voltameter hooked up. Perfectly fine. so its not the sensor, i have no leak, the actuator for the secondaries worked..(tested by THE MAN Jim from WAZOO lol) i feel that it has to be the fuel pump. I will need to test it with a gauge to know for sure.

[secondchance]

I suggest that you hook up fuel pressure gauge and take pressure reading. There are posts that shows pressure to be expected when on primary pump only (45 psi?) and when the secondary fuel pump engages also (50 psi?). As for the fuel pump part number, I'll have to look it up.