C6 F1a94, 2bar SD OS, FIC 200= delayed start up?? help

[regorih]

I?m turning this set up, and my start ups are not consistent. Sometimes it starts right up without any issue and then I could turn it off and start it and it just cranks and cranks and cranks and it sounds like it?s gargling similar to a backfire through the exhaust But not quite like it. I?ve been trying to figure this out for the past two days with no clear solution insight the car does have NGK spark plugs gap that .02 and a fore fuel system. Can somebody look at my file and let me know where I might?ve left off.

I have made several changes to the cranking, VE primary fuel table, running it from 20 all the way to 100 which doesn?t seem to help also mess with the cranking fuel and setting it to a quarter of the factory sometimes doubling it. I?ve also tried different start up timing, spark settings I?m just at the end of my rope.

One weird note is, the fuel system doesn't always prime as you key on, but as soon as you crank the engine fuel pressure will go up to 60PSI throughout the crank, and as soon as you stop cranking due to the engine not starting the pressure will go to 0 psi. All told to me that its normal from a Fore tech specialist.


Set up c6 corvette, forged piston & rod LS3, F1a-94 procharger, fore fuel system, external fuel regulator, FIC 200 lb injectors, full bolt ons, NGK non projected spark plugs 0.015 gap, e85 (86% ethanol), Speed density tune, HP tuners 2bar OS, currently in Open loop


*added a start up log*

In the log the car start up fine on the 1st attempt, I shut it off the car and attempted to start two more times without success and on the 4th attempt the car started up.

[regorih]

I'm thinking I might need to run a bigger spark plug gap, maybe what I have is too tight?

[edcmat-l1]

I would run more plug gap. Start around .025 like most NGK non projected tip plugs come out of the box, but I don't think that's your start up problem.

First thing is it's not holding pressure. Don't care what the guy at Fore says, if it's losing pressure it's going to affect the start up. I'd put a check valve in it.

Second thing is, the way you describe the sound of it when it won't start sounds like a cam sensor problem. The cam sensor synchronizes the injectors. When the PCM doesn't get the right cam signal, or none at all, it'll sound like an odd backfiring in the exhaust. And it'll usually start up every other time.

You don't have the P0340 code turned off. That's the code they normally set. And it doesn't look like there's one pending. But you do have P0016 turned off. Wonder what that's all about. I'd turn that code back on. It shouldn't be turned off. I would diagnose that code. Start by scanning your cam and crank sensor. Would be even better if you were able to scope both of them. I'd bet this is where you issue lies.

[edcmat-l1]

I would put this back in closed loop and use the trims to get it dialed in.

Why do you have the airflow scaled by roughly 50%? You doubled your stoich but your IFR is x .25 roughly.

[regorih]

I enabled P0016 and its not getting set. In the log I posted it has a pid for the cam and crank, and they both appear to be working.

[edcmat-l1]

You have a data log of it NOT starting?

[regorih]

yes in post #1 I've attached the start up data log. I did a total of 4 start ups. 1st one starts up ok, 2 and 3 did not, then on the 4th one it starts up.

[07GTS]

are those 200lb suited to ethanol ? if they are the Bosch 210 then they will cause issues on ethanol