Hello, my niece's H3 motor seized up, so I ended up swapping a used motor into it. Got it all back together today, it cranks but won't start. Fuel pressure is good, the passlock light with the car/padlock is not lit, I've rechecked all electrical connections and grounds, they are all in place. I'm hoping for a little direction in how I should be chasing this problem down. I have fuel pressure, I've tested the injectors via a Snap-On Solus Ultra scanner and you can hear them doing their thing. It acts like it has no spark whatsoever - not a chug or a cough out of it. Even got desperate and sprayed carb cleaner into the throttle body to see if it would react at all. No luck. If anyone has any suggestions about what to look for, I'm all ears. Thanks for taking the time to read and respond.

 

Year of H3 ?
Year of donor motor?
Straight swap or something else??
Each year is a little different.
2006 3.5l different stuff
2007 3.7l again a little different stuff
2008 & up a little different...lol!

 

Thank you for the response - I was a bit frazzled and forgot to include pertinent information - 2009 3.7 with auto transmission, not sure on the year of the donor, but it is another 3.7 - straight swap.

The good news is I found the problem today, which happened to be a blown fuse in the ignition slot - hole 33 if I remember right. Replaced that, and it fired up. Huge relief, I thought I was going to be chasing all sorts of sensors and wiring to figure out what was going on. I'm not sure why it was blown, but I started checking for spark this morning and couldn't get any, and the fuses was the first thing on the list to check. Got lucky on that, I guess.

Anyways, the H3 is running now, I just need to run it for a few days to make sure all is well and I can get it back to her.

Thanks again for reading and to Happy Hummer for asking the real questions. I will say this swap was one of the harder ones I've done, there wasn't anything easy about it. I'm glad it's nearly over, though I may be back at some point with other questions.

 

You missed the first step

 

X2 on the battery terminals. OEM are POOP!