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]

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.

[Johnny5]

i replaced both fuel pumps and checked the diff sensor under the ecm. The diff/map sensor is fine and the pumps are new. Still not opening the secondaries, hesitating and almost stopping at 5k rpm.

[Johnny5]

i did not clear the codes but 61 came up again.

[LGAFF]

http://www.corvetteactioncenter.com/forums/c4-corvette-zr-1-a/14272-1990-1995-zr-1-secondary-port-vacuum-diagnosis.html

[LGAFF]

peek down between the runners on the plenum and see if the actuators are opening the secondaries.....flashlight might help

[Johnny5]

Hey lee that article states that secondaries wont open if any ECM codes are stored so i will clear them after work and pray thats it but i doubt it lol. Thanks. I used a paperclip to read the coded. Can they be cleared in a similar fashion?

[Paul Workman]

Hey lee that article states that secondaries wont open if any ECM codes are stored so i will clear them after work and pray thats it but i doubt it lol. Thanks. I used a paperclip to read the coded. Can they be cleared in a similar fashion?

Lee isn't on line right now, but I dropped in to see how yer gettin along - hope you don't mind.

To reset all the codes, simply disconnect the battery for a minute or so before reconnecting the battery. If the code remains, then it is probably legit.

Good luck!

Paul.

[Johnny5]

Hey Paul. The code has disappeared but comes up when I plug the top right 2 pins with a paper clip. Will disconnecting the battery delete the codes from the ecm memory (as the light is not currently on)?

[Johnny5]

Disconnected the battery, replaced the MAP sensor as I found one very cheap and code 61 comes up for a second when flooring the gas. I pulled it after I took the car for a ride. Does anyone live close to NJ and have a Tech 1 that would be willing to help me diagnose this? I replaced the injectors (runs super smooth on regular mode but hesitates on full power), coil packs, fuel pumps, and spark plug wires. Code 61 is telling me I have a secondary issue but it could be anything in the whole secondary system. OOh btw I do not have a vacuum leak, and the pump does run and turn off.

[mike100]

hook an actual vacuum gauge to tube that goes to the under ecm map sensor for the secondaries. You should get a constant 13 inches of vacuum when you floor it if there isn't a massive vacuum leak somewhere else.

you may have to force the secondary vac solenoid to turn on if it won't activate due to restriction in the ecm with the fault...or clear the code and drive it once.

[Johnny5]

I am going to follow marc heibecks procedure and ground that part in back of the ECM. if the secondaries don't open......it has to be the solenoid, in which case i will have to buy jerrys and alter it or buy a new/used one off a member.

[Johnny5]

thanks for the tip Mike100. I grounded pin C17 on the ECM and heard nothing so the solenoid needs to be replaced. Hopefully that's the only issue. I'll let you guyx know after I replace it tomorrow or Saturday

[Johnny5]

I finally experienced the secondaries openning! Wow does this thing move in the high RPMs. Its diff than my brothers c5 z06. When i nail his car its like instant power from any rpm to redline. It feels like it has more torque. My Zr1 has a lil diff feel as if the majority of the power is all up top of the rpm band.

[LGAFF]

Throw some headers on it....

[XfireZ51]

I finally experienced the secondaries openning! Wow does this thing move in the high RPMs. Its diff than my brothers c5 z06. When i nail his car its like instant power from any rpm to redline. It feels like it has more torque. My Zr1 has a lil diff feel as if the majority of the power is all up top of the rpm band.

Once you go past the 1/8 mile, your brother will be seeing your taillights.

[Johnny5]

I hope so, i already have the targa top, now i want bragging rights lol

[Coupe89]

What do you replace?

[Johnny5]

It turned out no one plugged in the secondary actuator solenoid switch after changing the injectors. So if anyone wants a new sec solenoid i have one from Jerrys, that i dont need.

[secondchance]

It turned out no one plugged in the secondary actuator solenoid switch after changing the injectors. So if anyone wants a new sec solenoid i have one from Jerrys, that i dont need.

Wops! I'll take the blame. Glad you figured it out. My only excuse is that I had my secondary system totally removed. How fast we forget...

[Johnny5]

Feels good to finally open her up to 7k. The thing is idk why it was unplugged to begin with. We didnt need to unplug it to do the injectors and change the plenum and inj housing.

[XfireZ51]

Feels good to finally open her up to 7k.

Your journey to The Dark Side has begun.

[Mr Blue]

Your journey to The Dark Side has begun.

Could not agree more. When you first hear the 7K song it really moves you, then you here the stories ... and you say WAIT there's more??? More is good right. Power is addicting. If enough is good too much must be better. You have been warned.
David

[secondchance]

Feels good to finally open her up to 7k. The thing is idk why it was unplugged to begin with. We didnt need to unplug it to do the injectors and change the plenum and inj housing.

Normally we don't unplug secondary solenoid for injector servicing. That's why I wasn't even looking for it.

[Johnny5]

Maybe we did to test for leaks and never plugged it back but who cares now, this bitch is running great😄😄😄