SOLVED!! - After LS2 Intake Swap - Engine Won't Start
#1
SOLVED!! - After LS2 Intake Swap - Engine Won't Start
I have a 2004 LQ4 engine that I just swapped out an LS2 intake with LS2 injectors.
Engine cranks, but will not start. I shot some starter fluid into the TB and it cranks right up and runs for a couple seconds then dies. So this leads me to believe that for some reason, fuel isn't getting in.
I have a constant 58-60psi fuel pressure at the rail during cranking. I put a voltmeter to the injector plugs and they are getting voltage during cranking.
SOLUTION:
I pulled the fuel rail off with injectors attached, put some paper underneath everything to see if fuel was coming out of the injectors - cranked it over and saw NO fuel was coming out. So I know they are getting power, but none are firing.
I used a needle and pierced into each ground wire for the injector and grounded that wire for 1 second intervals - initially they did not spray, but after the 2nd interval they started spraying perfectly. I did this to all injectors - re-did the paper test and saw all were spraying fuel now.
Bolted fuel rail back on, cranked the engine and it fired right up no issues at all.
Summary: Fuel injectors must have been sitting around for a while, just needed a kick to get back going
Engine cranks, but will not start. I shot some starter fluid into the TB and it cranks right up and runs for a couple seconds then dies. So this leads me to believe that for some reason, fuel isn't getting in.
I have a constant 58-60psi fuel pressure at the rail during cranking. I put a voltmeter to the injector plugs and they are getting voltage during cranking.
SOLUTION:
I pulled the fuel rail off with injectors attached, put some paper underneath everything to see if fuel was coming out of the injectors - cranked it over and saw NO fuel was coming out. So I know they are getting power, but none are firing.
I used a needle and pierced into each ground wire for the injector and grounded that wire for 1 second intervals - initially they did not spray, but after the 2nd interval they started spraying perfectly. I did this to all injectors - re-did the paper test and saw all were spraying fuel now.
Bolted fuel rail back on, cranked the engine and it fired right up no issues at all.
Summary: Fuel injectors must have been sitting around for a while, just needed a kick to get back going
Last edited by TXjeepTJ; 06-26-2015 at 10:19 AM.
#3
Yup, check that too.
I might have found the culprit.. ebay adapter for my LQ4 TB to LS2 intake..The gasket on the adapter mounts to the TB, but the top section of the TB that is open - the gasket does not seal off half of this space.. Maybe I am getting fuel, this is just causing a very lean condition to where starter fluid is the only thing that can fulfill AFR
See pic!
I might have found the culprit.. ebay adapter for my LQ4 TB to LS2 intake..The gasket on the adapter mounts to the TB, but the top section of the TB that is open - the gasket does not seal off half of this space.. Maybe I am getting fuel, this is just causing a very lean condition to where starter fluid is the only thing that can fulfill AFR
See pic!
Last edited by TXjeepTJ; 06-25-2015 at 11:44 PM.
#4
I don't think so, sounds like the injectors are not turning on for some reason. 12vdc is supplied to the injectors at all times while the key is on, the PCM grounds each injector to open them. Sound to me like the pcm is not grounding the injectors for some reason.
#5
I just put JB weld in the port that is open/exposed to seal it up, I will report back tomorrow if that was the problem! (I saw this solution in a thread someone made a while ago, which he stated this area causes a large vacuum leak)