Injector Time Going to Zero

[LuckyX2]

Hi. I just rebuilt my bottom end on my engine and now that everything is back together, my engine (SR20DET) won't start.
The ecu (Haltech P1000) is counting the triggers properly and I have spark as confirmed by a timing light but I'm thinking fueling may be an issue.

I went to new injectors (ID1000's) along with building the engine and made sure to make the appropriate changes to the dead time table, flow rate, and fuel pressure. I'm using a VE map so there should be nothing to change there.

The strange thing is that if I monitor injector time during cranking, I get a reading fine until I step on the throttle and then the injector time drops to zero.
Why could it be going to zero like that? I'm thinking this could possibly be related to the not starting issue.

Also, when it's not zero, it's around 5ms. That seems like a lot of fuel for start up especially on my 1000cc injectors. Is it?

Thanks!

[jerryd87]

injector pulse time goes to 0 because stepping on nearly if not every fuel injected vehicle is to clear a flooded vehicle. the ecu sees that on cranking and cuts the fuel injector to clear out a flooded engine. 5 ms is way to high, i might be on a different engine but the vq35 actually has more displacement per cylinder and my cranking injection time is 2.374 ms at 68 degrees and 2.162 at 104 in my haltech platinum harness. idle i run a .8 ms injection time and that gives me 13.5:1 afr. i am running 1200cc injectors but considering the displacement difference im running half the actual fuel at cranking that you are. i also run 45 psi base fuel, not sure what you run?

[LuckyX2]

injector pulse time goes to 0 because stepping on nearly if not every fuel injected vehicle is to clear a flooded vehicle. the ecu sees that on cranking and cuts the fuel injector to clear out a flooded engine. 5 ms is way to high, i might be on a different engine but the vq35 actually has more displacement per cylinder and my cranking injection time is 2.374 ms at 68 degrees and 2.162 at 104 in my haltech platinum harness. idle i run a .8 ms injection time and that gives me 13.5:1 afr. i am running 1200cc injectors but considering the displacement difference im running half the actual fuel at cranking that you are. i also run 45 psi base fuel, not sure what you run?

That's just the info I was looking for. Things are close enough (1200cc vs 1000cc, 45psi vs 43.5psi, slightly higher cylinder displacement) that I can gather a rough idea of where things should be. One thing I should check though is if the ecu's display of injector time includes the dead time or not. That's gonna be at least a ms difference either way. Also, the ecu wasn't reading battery voltage correctly before but that's fixed. It was reading much lower and thus would have thought there was a higher dead time and given it more injector time. And it's good to hear that the fuel cut is normal.


As for where I'm at now... I had to go back up to NY unfortunately so the car is still in PA with my dad. He's been working with me over the phone to check things. Some new spark plugs and a few regroundings at least got it to start now and it sounds fine for about 10 seconds then just abruptly dies. My dad seems to think it's ignition timing because he got it running long enough to get a timing light on it and it was reading 4 degrees after TDC, almost 20 degrees retarded from where it should be with the cas turned fully advanced. He checked the cas, sent me pictures and everything and all the timing setup is spot on.

Any idea why timing would be so far off? The cas is known to be good by the way. It worked fine before the rebuild.

Thanks.

[LuckyX2]

Well it's running now but only with a band aid. And idk what my dad was talking about but the timing was fine.
It took a fuel trim bump of 75%...

Something is definitely wrong because there is no way it should take 75% more fuel. And even then it was running a bit lean (15.2AFR).
My current guess is that my fuel pressure gauge or FPR is broken. In the process of getting new injectors I needed a new rail, FPR and pump too and along with the new FPR came a new gauge.

I have everything set up correctly (or so I think) so it must be something with the new fueling setup.
-Injector flow is set to 1015cc (ID1000's at 43.5psi)
-Base pressure is set to 43.5 psi on both the ecu and the FPR at 0 vacuum.
-Injector resistance is set to high (measured 12 ohms)
-Dead time is setup exactly as Injector Dynamics specified

Here's some info during idle:
http://i47.tinypic.com/2nrht8z.jpg
Injector time wound up being about 2.5ms at the (high) idle of around 1500rpm and dead time is about 1ms. Is dead time already factored into the 2.5ms? By that I mean is 2.5ms the true open time of the injector?
And 2.5ms seems low considering fuel trim is an additional 75% and VE at idle is 76.5%. And yes, I know the VE is off but the old map was built around the old injectors with unknown dead times so I'll have to redo it.
Also, I'm not sure why it says 0 for the fuel trim because we definitely put in 75...

http://i46.tinypic.com/2duwhzp.jpg

Thanks again.

[jerryd87]

unfamilar with that page as the platinum harness version dosnt have it(the overall fuel trim) but that dosnt factor in the dead time, at 14 volts my dead time is .7 ms and theres no way my actual injector open time is only .1 ms. that does seem incredibly high though mayby its because of your high impedance vs my low impedance injectors?

or possibly clogged filter or something? i imagine these are all ruled out already but dosnt make much sense that is a lot of fuel for idle from such a small engine, i would expect that from a beefy v8. something is definitly going on try to rent a fuel pressure guage from autozone and verify that vs your guage.

[LuckyX2]

Well I looked into it and found out my FPR is a fake...

Chances are that POS is what's causing the problem. I'll be buying a new one from a reputable source today but in the meantime, I have a known good gauge to compare to the new knockoff gauge and maybe I can see what it's actually doing.

With the knockoff FPR and gauge I set it to 3 bar at 0 vacuum then at idle (20inHg of vacuum) it reads 2.5 bar. We'll see what the good gauge says...