Did Engin Swap" crank but no start"need help"
 

hey, everyone im new hey ,well im haveing some trobles..ive just done an engin swap on my G35 i bought i wracked g35 s same year and every i paid for the car got into it to be prepared to get pulled to my house which is only 2 blocks away i try to start it and its starts right up no problem.. wait a few days and i took the engin out and put in into my car hook up all connecter ect. now im done my car will not start but cranks and just rev rev rev thats it.checked fuses an relays they seems to be good..have checkedsrark plugs .can i get some help here please and thank you

What year, sedan or coupe?

Does the tachometer move when cranking?

Does the NATS security indicator next to the dash turn on? Is it solid red while cranking?

Have you scanned for OBD2 codes?

Did you keep the existing ECM, BCM?

i have 2007 g35 sedan stocked i put in my scanner no codes came up only came up in the frezzeframe was p1564 and i did put the ecu from the car i bought into my car but i took it out and put mines back in ..there telling me the i needed to reset my ecu i did dat ,that didnt work so now going to see if i have spark

and all lights come yes the tachometer moves when cranking

You can't just swap ECM's, they are mated to the BCM and ignition module, it's all part of the NATS/IVIS security stuff.

So you currently have the existing computers in the car yes? And you did this with the battery unplugged yes? Computers don't like being unplugged while they are energized, it's likely to be damaged so don't take chances.

The P1564 is an error with the cruise control switch being read by the ECM. Did the cruise control work previously? This can also be caused by unplugging the ECM while it's energized, thus why I asked.

Do you hear the fuel pump prime for 1 second when you turn the ignition to the ON position? If you're having trouble hearing it open the gas cap and listen directly into the tank while someone else turns the ignition on.

Tach moving means you're getting crank position signal.

Did you keep all the existing sensors and injectors from your original motor? Normally I don't ever recommend using the donor engine sensors/injectors (at least for a first startup). You're introducing a LOT of potential problems, if one of those donor cam sensors isn't working then it's not going to start. Same thing with existing fuel injectors, throttle bodies, MAF sensors, etc. You want to start with the equipment that you KNEW was working properly from the old engine.

You can pull a spark plug and hold it with the ground strap about 1/4" away from a ground source (HR engine uses a plastic intake manifold so that won't work). If you're getting spark then the engine is at least TRYING to open the injectors. If there's spark then pull all the plugs and see if they're wet with gas, if they're not it's probably clogged injectors.