New fuel rails, now won't run
 

Hi all,
Please help. I put new Jegs fuel rails on. Started up after testing for leaks. Ran fine for a second, then starting clunking, and died. I can't think of what could be wrong....

Check if your injectors are getting fuel, sometimes fuel rails are not properly cleaned from factory and can have debris in them which can cause your injectors to get clogged and or run really rough.

How would I check to see if injectors are getting fuel? The car won't stay running long enough to do an audible test

Describe the path of your fuel from the feed into the rails to the return rail exit and then to the regulator. That might be the issue.
What's your fuel pressure at the regulator?

I don't have a FP gauge. It is a 2010 Camaro SS. Went from "flipped" stock rail to something like the Holley fuel rails. I simply disconnected the existing fuel inlet, took out the rail and injectors, made a longer inlet line, and put new rails on with injectors. Car rans smooth for 10 seconds or so. Then shut off violently. Sounded like a wrench in the crankcase. Checked things over again and tried to fire it back up. Hard to start, and only runs for a second or so,, clunking violently, and dying...…… :(

I'd be looking for mechanical problems, the way you make it sound.

I would review this post #5

https://www.camaro5.com/forums/showthread.php?t=318034

The only thing different I can notice is that the fuel injectors sit down farther in the intake. Could they be to close now? Before you could see the orange O ring. Now you can't see any of it....

Try putting the stock fuel rail back on and see if it starts up no problem. Then you would know for sure if its injectors or the new rail you purchased

I just switched back to stock. Tried to fire up. And now it seems like the engine is locked up. Pulled the codes. P0303. Crankshaft rotation speed variation.

How do I go from a great running car to this??? Just by switching fuel rails. Engine won't even turn over!!!

I have a feeling the issue is non-fuel rail related. Something broke.

I have that feeling also. I just don't know where to begin since this is the only thing that I have done to it...

Probably just a coincidence. Start pulling it apart. It's the only way to find out what the issue is.

Just speculation but based all of the parameters and calculations made by the emc to control the fuel pressure, one being the calculated pressure in the rails (see post #5 referred in previous post ). For example, if the aftermarket rails are hogged out to 10 AN and the stock rail ID is only 8AN that could be enough to throw the calculation out of the predetermined range). A leaking fuel injector too can throw that code as well based on #5 because it reduces predetermined pressure.

Actually all of calculations mentioned in #5 makes sense in order for the fuel pump (pulse width modulated) to regulate variable fuel pressures determined by all of the sensors compared to a simple fuel pressure regulator.

"The ECM monitors the fuel rail pressure sensor and the high pressure fuel pump actuator to determine if the commanded and actual pressure are within a predetermined range, or if the amount of fuel pressure correction exceeds a calibrated pressure."

"The high pressure mechanical fuel pump (under the manifold) is driven by three lobes on the camshaft . The ECM uses the camshaft and crankshaft position sensor inputs to synchronize the high pressure fuel pump actuator with the position of each of the camshaft lobes. The ECM regulates fuel pressure by adjusting the portion of each pump stroke that provides fuel to the rail."

Sounds now like the ecm thinks the crankshaft position sensor is saying the engine is out of time.

You didn't by any chance remove one of these sensors and not reconnect it or not completely connect it? Surely you don't have to prime this type of fuel system when replacing parts.

Think I will keep driving my 98.

Do you have to use a Tech II to reset the ECM on the Gen V's.

With all of this technology, no wonder these GEN V's make a lot of hp and still get good gas mileage.

There is no middle, or end to this story. Just, something was wrong, then fixed itself. I really appreciate you guys going out of your way to help. But I am at a loss as to what to do now. I can't test that theory behind rail pressure if I can't get the car to turn over and start.
And yes. I see the science behind the rails being "hogged out". These rails would def fall into that category.
Do I unplug the battery now and let it all reset? Then try to start it again?

I don't think it that easy Gen V.

https://ls1tech.com/forums/pcm-diagn...procedure.html

You think I should do the CASE relearn? That scares me because if something goes wrong, I feel it will somehow lock me out (of the whole system) and I would be screwed

Pull the plugs and see it she turns over.

Fueling & injection
 

I am also facing the same problem..:(

Sorry to hear that! Did you too only replace fuel rails? And then engine won't turn over? I don't know if I need to tow it to someone who has a Tech II, or tear the intake and heads off. I AM CONFUSED AS ALL GET OUT...…..