One of the things I have noticed is now using a FPR with gauge is that if you turn the pressure up the car will almost never start. If you reduce the pressure to stock or lower, the car will start right up. Maybe there is too much pressure behind the injector for them to open while cranking and once the pressure at the rail has had some TIME to trickle down back through the pump it will start?

 

Yea from my finding and working with the tables I just dont think it has to be that precise.....i mean if its waaaay off yes, but setting up the tables with the proper calculation should be "close enough" imo to see a change or get the car to fire. Also brings me back to the member rawkus who has not touched any start-up tables and he has no reported starting issues.....so other than his injector settings he is working off the stock starting tables.

example: I had pte 880's for a while and that was before we had the starting tables defined and by doing some low volt latency changes I got them to start like stock and never modified "other" tables.

Yea it does feel that way but according to the logs it should be getting fuel? I mean I zero'd out that one table and the motor cranked and cranked and I actually logged "0" IPW - so it was def. not getting any fuel but it felt the same while cranking.

weather depending I am going to get the car cranking, shut down, and pull the plugs to check and see if they are wet - I need to throw my new plugs in anyway so I can check this while I am doing it.

Yea and I agree the first set of cranks it doesn't even act like its trying to catch but as soon as stop and restart cranking again the car fires right up with the same dang IPW value - again see my log. I can also immediately turn the car off keeping the coolant temp near the same and restart without even a hiccup again with the same IPW values, etc. But if i let the car sit for 15+ min. it will have problems starting again......

Sometimes I can get it to fire on the 1st of cranks but were talking 8+ cranks and it will slowly sputter to life - but it wont always do this.

 

so your saying the stock pressure might be to much? because I run the stock fpr (unmodified/crushed)...

 

Too low of a voltage along with high of a rail pressure can keep the injector from opening. I've seen it in bench testing of several different kinds of injectors, including a set of EV14s. The EV14s actually did pretty well at low voltage though. However, it would be interesting to relieve the pressure right after engine kill, wait the usual amount of time, and then try starting the car.

 

This is what I have planned to test again because as I stated earlier I saw this curing the problem the day I was taking my old FPR on/off but its been a while and I want to confirm BEFORE I say it actually works.

maybe i will do this right after work when i get home.....unless it starts raining again.

 

I have been so frustrated with this issue on multiple sets of 1600cc that now I see that it happens over and over again. I couldn't get the car started for a day after the install, then after getting pissed off I took off the rail and flipped it to see if they sprayed, shot an injector out of the rail, said screw it and put it all back together and it started.

I have come to this conclusion about voltage/fuel pressure over the course of it happening to multiple cars and then once I had a FuelLab FPR added with gauge I turned up the pressure 10psi and it would not start for hours. I turned it back down to below 40psi and it fired right up.

 

You missed my comments a few pages back. There it goes!



If you had high pressure in the rail why wouldn't the FPR open and relieve the pressure?

 

Sorry if I missed it, trying my best to keep up with this, but has anyone actually logged or at least monitored fuel pressure when this is happening?

The injectors will open with no problems as low as 8v with less than 75psi FP. Now, something to consider, the injector dead time changes significantly at low voltages and high pressures. If the pressure is raising in the rail and your cranking voltage is say 10v, you could be close to a 2msec dead time. If your cranking PW or initial PW aren't taking the dead time into account properly, a 1.5msec PW command would result in no fuel flow. You SHOULD be able to counter this with additional cranking fuel though.

 

Maybe someone should measure voltage at the injectors during cranking?

 

I watched my mechanical gauge at the fuel rail when someone else was cranking it and it was bouncing around 40psi-44 psi that i recall during cranking - would have to look again, its been a while.

I think dan and I will have to get together in a few weeks and do some testing on both cars side by side under the same conditions and see the variations......he has a garage and equipment to test voltages and stuff so if he is willing I am sure we can get that info at the injectors. (I am limited with apt. living and no garage)

 

Idea's from some co-workers

Karl S. – leaky injectors (possible)
insufficient cold cranking amps from mini battery
MAP sensor problem (interesting... i think we all have different map sensors!)
(Senior Electrical Engineer)

Jin K. – we don’t have control over “rundown fuel injection” therefore you need a time based compensation for IPW. Jim said that “ALL OEM’s HAVE THIS”... I asked him what % of sure he was and he said 100%. (worked for GM/Chyrsler)

Jin thinks that the car is rich during starts and needs to be instrumented with an uninterrupted Wideband logging to prove this. Also seconded the need for a fuel pressure gauge.

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Everyone want’s to know what hardware is on the car that runs fine vs. the cars that don’t run well. We need a COMPLETE LIST of everyone’s modifications.
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Clarification needed: did the car with the good injectors put them in the car that wouldn’t start and vice-a-versa? Who put what in who’s car? Much detail needed here.

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Can I get everyone to post up EVERY mod they have done to their car as well as vehicle info?

R/TErnie
2006 Evo 9 88950015
v5.10 Tephra Patch
Mr. Fred PSI based Boost Control
OMNI 4 bar MAP
AEM EBC solenoid
Walbro 255 HP pump
ID 1000cc injectors
HKS Green Foam Intake filter
FP intake tube
FP Red Turbo w/18psi actuator
3" TBE (no cat) rear o2 still in place.
AEM Wideband
FMIC
Magnus Intake Manifold
LICP and UICP
TiAL 50mm bov (vta)
Muse battery tray w/ Oddyssey PSC680 battery
STOCK LONGBLOCK (valve cover to oil pan... aka NO CAMS)
My ground strap on the intake manifold is still present
My ground strap on the Ground terminal is grounded to my mini battery.

 

I have some comments about the videos posted. The 52 minute start up sounds like 3-4 cranks before starting. The 20 minute one sounds like 5 cranks. In my car immediated restarts when hot are 2-3 cranks. Hots starts at 25 minute tp 5 hours or more are 10-12 cranks to start or 3-4 cranks/stop, 3-4 cranks/stop, starts at 3 cranks on 3rd try.

From the video, my engine doesnt turn that crisply with my mini battery that I use. I wonder if that might be a factor in my case.

 

Though not 100% relevant, some info from a car I have on the dyno right now.

ID1000's at 50psi

Cranking ipw at 136F engine temp, 9.8V, is 6.29msec

Cranking ipw at 186F engine temp, 9.7V, is 4.79msec

Fires right up in both situations.

For reference, ipw at idle, 185F ET, 14V, 14.9 a/f ratio, is 1.64msec at 940rpm.

Forgot to mention, this is on an Acura RSX with a K Pro. Stock engine, 93 octane.

 

Tony can you take a video of the car starting?

Run the car up to operating temp.
Turn off the car
Wait 52 minutes
Start the car while taking video.

let us know what the pulse width and voltage is when you do it please.

 

MAP sensor - Doesn't play a role during startup (or really another time on a MAF based Evo).

Rundown - Do you mean time-based shedding of IPW during cranking? If yes, we now have it. See my advance fuel control post.

My setup:

2006 Evo 9
Amsoil cone filter or stock airbox (have tried both)
FMIC
LICP
TBE with ported manifold, ported Titek O2 housing, and metal subtrate cat
Walbro 255 (without pressure relief mod)
stock battery
all ground straps unmodified
88590015 tuned ROM with most of my patches
running e85 98% of the time