5.3 swap engine not starting
Thread Starter
Staging Lane
Joined: Mar 2018
Posts: 73
Likes: 8
5.3 swap engine not starting Hello,
Here goes my first post and I hope I've done this correctly.
I've swapped a Chevy 5.3 into my jeep, Ive always had difficulty starting the thing. Upon first start, it took a good while to finally get it to start. It would be hit or miss, some times it would start, some times it would just turn over. It sounds like it wants to start, just at the beginning, but then will just turn over. I had always assumed it was air in the fuel line...
I noticed a gas leak around the pump/fuel line fitting. I went ahead and replaced the pump... I havent gotten it started since.
What I have:
Engine will run with a gas soaked rag over the intake.
~53lbs of fuel to the rail when i turn the key on
~50 to 60 lbs of fuel to the rail when turning the engine over
all injectors are spraying fuel except for the rear passenger injector (should still start withh one injector down)
What could the problem be? could the injectors be spraying fuel but not enough? any suggestions would be helpful because I have been fighting this for a while and I want to get this thing on the road.
Here goes my first post and I hope I've done this correctly.
I've swapped a Chevy 5.3 into my jeep, Ive always had difficulty starting the thing. Upon first start, it took a good while to finally get it to start. It would be hit or miss, some times it would start, some times it would just turn over. It sounds like it wants to start, just at the beginning, but then will just turn over. I had always assumed it was air in the fuel line...
I noticed a gas leak around the pump/fuel line fitting. I went ahead and replaced the pump... I havent gotten it started since.
What I have:
Engine will run with a gas soaked rag over the intake.
~53lbs of fuel to the rail when i turn the key on
~50 to 60 lbs of fuel to the rail when turning the engine over
all injectors are spraying fuel except for the rear passenger injector (should still start withh one injector down)
What could the problem be? could the injectors be spraying fuel but not enough? any suggestions would be helpful because I have been fighting this for a while and I want to get this thing on the road.
Thread Starter
Staging Lane
Joined: Mar 2018
Posts: 73
Likes: 8
I'm looking for any type of help.
I removed the fuel filter as I have read the corvette regulator also acts as a filter. I thought this might be causing a drop in pressure. I bypassed this. Now it will crank for maybe 4 cylinders to fire, then nothing.
I'm stumped.
I removed the fuel filter as I have read the corvette regulator also acts as a filter. I thought this might be causing a drop in pressure. I bypassed this. Now it will crank for maybe 4 cylinders to fire, then nothing.
I'm stumped.
Thread Starter
Staging Lane
Joined: Mar 2018
Posts: 73
Likes: 8
I swapped the 3rd and 4th injectors on the passenger side and the third injector didnt fire. So the injector is the problem and it's not electric. I'll be replacing the injector.
Im beginning to think the jeep pump isn't enough to power the 5.3.. I've heard that it is, but I have an aftermarket Carter pump. Maybe it's just not stong enough.
Im beginning to think the jeep pump isn't enough to power the 5.3.. I've heard that it is, but I have an aftermarket Carter pump. Maybe it's just not stong enough.
Thread Starter
Staging Lane
Joined: Mar 2018
Posts: 73
Likes: 8
Replaced the fuel pump yesterday with a walbro pump. While the fuel pressure gauge shows this pump is infinitely better than the previous one, as it's at the correct pressure and gets there with just one turn of the key rather than three or four, I've still got no start. Just a few stutters, maybe three then nothing.
although, one time it did start for probably 5 seconds.
my fuel injector that I bought to replace the one that isn't firing will be in today and I will be replacing that one.
Again. If anyone has any ideas, I'm all for hearing them.
although, one time it did start for probably 5 seconds.
my fuel injector that I bought to replace the one that isn't firing will be in today and I will be replacing that one.
Again. If anyone has any ideas, I'm all for hearing them.
If you get make it run with another fuel source then it's not getting enough through the injectors. Since your new pump works much better it sounds like you had 2 or more problems and are down to maybe one.
Why didn't the one injector spray? Was it dead, stuck, or clogged? If it was clogged are others also clogged? You can jump the wires on the injector and you should hear a click, if you don't spray some cleaner in it and beat it on the bench with and without power. If it does click then it much have been clogged. When you get your new one you will have one to compare the others with. You can use water from a garden hose (usually about 60psi) to test the flow in pinch. Just have to flush it out or put it to use quickly so water doesn't set in it and cause problems. My guess is you have junk in the injectors. Never run without a 10 micron filter and flush new lines before you hook them up to be safe.
Why didn't the one injector spray? Was it dead, stuck, or clogged? If it was clogged are others also clogged? You can jump the wires on the injector and you should hear a click, if you don't spray some cleaner in it and beat it on the bench with and without power. If it does click then it much have been clogged. When you get your new one you will have one to compare the others with. You can use water from a garden hose (usually about 60psi) to test the flow in pinch. Just have to flush it out or put it to use quickly so water doesn't set in it and cause problems. My guess is you have junk in the injectors. Never run without a 10 micron filter and flush new lines before you hook them up to be safe.
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Thread Starter
Staging Lane
Joined: Mar 2018
Posts: 73
Likes: 8
I replaced all the injectors with remanufactured injectors, cranked it up and it still will fire on four is cylinders and die. Enough so that I bring the key out of the start position to th run position.
I'm almost convinced air is in the fuel lines. What else could it be?
I'm almost convinced air is in the fuel lines. What else could it be?
Last edited by JonHerrington; Mar 23, 2018 at 09:49 PM.
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I replaced all the injectors with remanufactured injectors, cranked it up and it still will fire on four is cylinders and die. Enough so that I bring the key out of the start position to th run position.
I'm almost convinced air is in the fuel lines. What else could it be?
I'm almost convinced air is in the fuel lines. What else could it be?
Thread Starter
Staging Lane
Joined: Mar 2018
Posts: 73
Likes: 8
https://youtu.be/nFFmlB9kKAU
this is its first start up. It took a lot of cranking to get it to that point. Then even after that it would be hit or miss. Like I went through a point where it would start and fire on three cylinders then nothing, then one day I started it up and it ran fine but I couldn't really get it to move.
while the nt being able to easily move might have something to do with it, maybe it's in low power mode too?
just throwing stuff and seeing if anything sticks.
this is its first start up. It took a lot of cranking to get it to that point. Then even after that it would be hit or miss. Like I went through a point where it would start and fire on three cylinders then nothing, then one day I started it up and it ran fine but I couldn't really get it to move.
while the nt being able to easily move might have something to do with it, maybe it's in low power mode too?
just throwing stuff and seeing if anything sticks.