VP 5.0 to 5.7 high idle

[joelewis73]

Swapped out two 5.0 block for 5.7 blocks over the last year due to sitting for so long and water intrusion. They are both TBI engines and not carbed. 2000 model PEFS is the serial number in them and trying to figure out the high idle issue I have. Not sure how to adjust the idle, the engines are practically brand new with the exception of the MAP sensor and that is next unless someone points me in the right direction..
They both have new intakes and no they are not leaking as I can tell, new IAC and TPS have been installed. Today I started them and they are both running at 1500 rpm constant at idle no hunting or surging just running at 1500 rpms. Other than having two bad MAP sensors.
I have not set the electronic timing yet because the idle is so high and not sure if it was safe to do so. Any help is greatly appreciated and I have looked for this numerous times before I posted it. If you have another post that covers it please forward it my way and I will read it.
Thanks
Joe

 

[alldodge]

Two motors doing the same thing. Either they both were setup incorrectly, or the same item is not working right

Hope throttle cables are disconnected to ensure the cables are not increasing rpm

Try to set timing, if its to far advanced the ECM will try to keep things at optimum burn. Even if just adjust dizzy to see if it can be slowed down

If unable to slow down, then need to start checking for a vacuum leak

 

[joelewis73]

Two motors doing the same thing. Either they both were setup incorrectly, or the same item is not working right

Hope throttle cables are disconnected to ensure the cables are not increasing rpm

Try to set timing, if its to far advanced the ECM will try to keep things at optimum burn. Even if just adjust dizzy to see if it can be slowed down

If unable to slow down, then need to start checking for a vacuum leak

Thanks will check it out tomorrow. Was not sure if it was a ecm issue with going from 5.0 to 5.7 but could not see that being it. I did have to rebuild the entire wiring harness since they are not available anymore which sucked for certain.

 

[alldodge]

Dont see an issue currently with the 50 to 57 swap

 

[joelewis73]

Dont see an issue currently with the 50 to 57 swap

I didnt either but the RPMs are a worry. It jerks into gear as it should with that high of a range. Just want to tone it down a little back to where it should be.
R
Joe

 

[joelewis73]

So just wondering....I unplugged the IAC and the TPS and nothing but a little shudder but as soon as I unplugged the MAP sensor it chocked off. Is it supposed to do that?

 

[alldodge]

Unplugging any of those will throw a code, and has a possibility of damaging the ECM. Not saying it will/did but its not a good idea. Don't know what "chocked off" means, but if it means shut down (turned off) I would say that is possible. The ECM uses the TPS and MAP to determine how much fuel the motor should get

 

[joelewis73]

Unplugging any of those will throw a code, and has a possibility of damaging the ECM. Not saying it will/did but its not a good idea. Don't know what "chocked off" means, but if it means shut down (turned off) I would say that is possible. The ECM uses the TPS and MAP to determine how much fuel the motor should get

Yeah Choked...typo...

 

[joelewis73]

I got the port engine reset today and sitting around 750 so i feel much better. Was/am still trying to figure out the stbd eng. Since I replaced the intake been having issues getting it started. Bone head move on my part I actually put the wires in the wrong order. I figured that out but it still will not start right this minute but I have tomorrow to work on it. I am sure I am missing something or am off just a little in the timing. Does not sound like it is getting any fire/spark now. Tested all connections to ensure there was 12v and there is voltage avail where it is supposed to be.

 

[Scott Danforth]

running the 5.7 on a 5.0 calibration means the motor will be running lean. even with the electric toilet on top (TBI)

make sure the throttle cables are not holding the throttle open.

 

[alldodge]

The good thing is having MEFI's they can be reprogrammed by many. Can even be done by yourself with MEFIBurn software, and AFR meters

 

[joelewis73]

running the 5.7 on a 5.0 calibration means the motor will be running lean. even with the electric toilet on top (TBI)

make sure the throttle cables are not holding the throttle open.

Had them disconnected

 

[joelewis73]

The good thing is having MEFI's they can be reprogrammed by many. Can even be done by yourself with MEFIBurn software, and AFR meters

Yeah my buddy has the program for his boat and he is gonna come over and check it out with is cpu.