5.7L Vortec Swap

I have recently replaced my 5.7L non vortec volvo penta with a 5.7L vortec volvo penta long block, due to a cracked block...I have replaced the plugs, wires, cap, rotor, new vortec intake, had the injectors cleaned, and the ecm recalibrated for the vortec files...Before having the ecm recalibrated the boat would lean spit when you were to give it any gas, as well as idle rough...Now with the ecm recalibrated it idles great but will die when you give it throttle, as if it is getting to much gas...My questions is, what all needs replaced when doing this kind of swap? I have heard several say it is a pretty common swap and that all I would need to replace is the intake manifold...Any help would be greatly appreciated...

Re: 5.7L Vortec Swap

You need to put in some detail in your post. Assuming its a volvo what model yr was the orignal engine? what model yr is the new engine? Was this a mefi1..2..3 one would assume a 1 or 2.....was the old enigne tbi or mpi whats the new engine tbi or mpi..who did the reflash a very detailed explantion should provide result's....The knock sensors mefi 1 use a differnt knock sensor than a 3 and a modern engine is setup for 3 and above.

Serial number's of the old engine will be critical.

Re: 5.7L Vortec Swap

Sorry, the original engine was a 1997 with Tbi and the new is a 1997 with Tbi...The ecm is a Mefi 1 and was reflashed by OBD diagnostics...As for the serial number off the old motor I could not tell you...It was sent back as a core...

Re: 5.7L Vortec Swap

Without exact engine descripton's your job will be difficult.. I would check the timing what method was used to set the timing aka did you use a shunt to set the timing or this method..Is this is a delco est dist which you method did you use

Connect timing light to number 1 spark plug wire.
2. Start engine and run at 1300 rpm until it reaches normal operating temperature.
3. Stop engine and connect the scan tool or timing tool to the DLC connector on the EFI/
MPI wiring harness.
4. Start engine, allow rpm to stabilize.
NOTE: MEFI-1 models only, manually adjust remote control throttle lever to get 1200 engine
rpm.
NOTE: MEFI-2 and MEFI-3 models only, ECM will automatically adjust engine rpm to
approximately 1200 rpm when put in the service mode on a scan tool or when using the
timing tool.
5. Check ignition timing. If incorrect, rotate the distributor until timing is correct. Torque
clamping screw to 18 lb-ft (25 Nm).
6. Recheck ignition timing.
7. Disconnect scan tool or timing tool from DLC connector.
8. If required, return remote control throttle lever to idle position and shut off engine.
9. Restart engine, increase rpm to 1300 then return to idle position slowly. Ensure that
engine returns to idle rpm. Readjust throttle cable, if required.
10. Shut engine off.
Spark Plugs

So did you use a shunt.....or a timing tool? Below is a shunt



And the EFI timing tool...The shunt connects to the dist and the timing tool connects to the ecm or data link



The next step's would be to put a fuel pressure gauge on the fuel rail which should read a constant 28-35 lbs..they can be rented from most part stores.

Your new vortec intake is it a marine intake or a edelbrock type..and model number. And the new vortec head uses a long plug tip which is different from the older heads you had.