5.3 Swap No Start
Thread Starter
On The Tree
Joined: Apr 2010
Posts: 116
Likes: 0
From: 78155 TX
5.3 Swap No Start Hello,
I have a 2002 5.3 Swap going into a 78 K5.
I' am using the wiring diections from, http://lt1swap.com/underhoodfuseblock.htm, and had my ECU tuned buy him as well. I have direct 12 volts to the C1 B11, and ignition power to the C1 A9 but it is not on a relay, would that make a difference? I am not getting spark, I have tested the crank sensor and replaced it. All my grounds are good. One thing I just realized is that maybe my ignition source is not staying on during cranking.
Any other suggtions I am missing?
Thanks
I have a 2002 5.3 Swap going into a 78 K5.
I' am using the wiring diections from, http://lt1swap.com/underhoodfuseblock.htm, and had my ECU tuned buy him as well. I have direct 12 volts to the C1 B11, and ignition power to the C1 A9 but it is not on a relay, would that make a difference? I am not getting spark, I have tested the crank sensor and replaced it. All my grounds are good. One thing I just realized is that maybe my ignition source is not staying on during cranking.
Any other suggtions I am missing?
Thanks
TECH Enthusiast
Joined: Sep 2014
Posts: 732
Likes: 1
From: alburnett, iowa
go over all your connectors make sure plugged in. cam sensor plugged in? you can use your old hei wire for the key on hot in run as thats what it did in sbc. Thats what i used for that on my buick, works fine and its heavy wire too. i used his to had little trouble. double check your fuse block/relays for correct cordination. i did mine had wiring reversed by way i held it putting it together. changed that around fired rite up.
Make sure the ground at the front of the block behind the power steering pump is hooked up. It is easy to miss and is the ground for the coils. Also, what wire are you powering up the harness with? As stated above, use the wire that used to go to the HEI distributor, that is the one that will stay hot during cranking.
Thread Starter
On The Tree
Joined: Apr 2010
Posts: 116
Likes: 0
From: 78155 TX
I checked all grounds, the 2 at the rear of the block and the one by the pump.
I noticed I wasn't getting voltage while cranking. I reran my the wiring to a source that gets power while cranking, but it drops down to 8-9volts instead of staying at 12. I think I am getting spark now, it must be horribly flooded by since I have tried staring it so many times, seems like to wants to start I can here some exhaust pop coming out the manifolds. My starter starting seeming like it was getting weak, I wouldn't have a constant crank, it was crank slow. Then yesterday after I fixed the wiring it the started wouldn't turn the engine over and was making a weird noise.
I noticed I wasn't getting voltage while cranking. I reran my the wiring to a source that gets power while cranking, but it drops down to 8-9volts instead of staying at 12. I think I am getting spark now, it must be horribly flooded by since I have tried staring it so many times, seems like to wants to start I can here some exhaust pop coming out the manifolds. My starter starting seeming like it was getting weak, I wouldn't have a constant crank, it was crank slow. Then yesterday after I fixed the wiring it the started wouldn't turn the engine over and was making a weird noise.
