I have a h22 built motor, with a 60-1 air to liquid running with 96 lb msd injectors, and my engine management is a FAST. This beast idles like hella rich! Like 9.5-9.9 to 1. We tried taking out fuel out of the VE table, but that only does 9.8 to 1 at best. I figure with these injectors, i can at least get them to 11 to 1. Perfect air fuel at my location is about 12.4 to 1. I was looking at my injector opening time on my setup and it is set at 1.8 ms, doesn't that seem a little too long? I was more of thinking like .8 to 1.0 ms. What do you guys think? You think that will help with the idle? I would try it myself, but unfortunately were waiting on the return of my o2 sensor.
Your input would be great.

 

bump

 

1ms to 2ms is fairly typical for warm idle injector pulsewidth.

I'm not sure such a big injector could even handle such a short pulsewidth without misfiring.

How much ignition advance is allocated to the idle cells? Maybe you're not running enough ignition timing.

 

I agree, you're going to have trouble idling those injectors with a pulse width less than around 1-1.2... Just a guess..... you can reduce the area in the map where it idles until it dies and see how short of a pulse width the injectors can fire consistantly..

Another option is lowering the fuel pressure... hopefully you're running a decent FPR to raise with boost 1:1.

I don't have any experience with the msd injectors, but I assume they are peak and hold?

hth

 

I run 26 degrees at idle, I talk to a Mike (Tech rep for Fast), he's the one who told me I should run .7 to 1.0. Thats why I thought I would ask on here. I am idleing at 50 psi with vaccuum disconnected on the FPR. My Fpr is talking a **** on me too, it is a aeromotive and before i was at 50 psi now i'm idling at 30 psi. I haven't even adjusted it, and even installed 2 new pumps, the inline and in tank, and I cleaned out my fuel filter. What do you guys think about the fpr? I opened it up and the rubber seal apears to be ok and the pressure does jump 7-8 psi when i disconnect the vaccuum, I was maybe thinking the check ball was bad.
ohh well thanks for the input.

 

anyone

 

what is the fuel pressure with the vacum line disconnected; 30 or 50? If it is not staying consistant with that fpr, it is time to get a new one...

always make sure the engine is consistant mechanicly before making adjustments in the ems.


it's easy to calculate what the pulse width should be... but you'll just have to test and see what the engine is happy with. Have you tried reducing the pulse width at idle until the engine dies?

I can't run any less than pulsewidth than .9 on my B16 and it will die with an 12:1 on the w/b. lol.. but I know I need a different fpr.

 

The fpr is idling at 25 and when i disconnect the vaccuum it goes up to around 32. but as soon as i shut the car off it drops immediately to zero. as soon as i get this fuel issue solved, i will turn down the ms to around 1.2 and see where that goes.

Also i upgraded from batch to sequential, but my sponsers fail to insall a crank refenence signal, so therefor it's still functioning as a batch or a bank mode.

 

if it's holding 32psi at idle with the vacuum line off, it's good... you may try to drop it 5 more psi and see how it does... as far as the differences with the vacuum line and going to 0 when you shut off the car, those sound normal.


if it was running decent running batch fire, I wouldn't change to seq until you get the idle a little closer.. I don't think it's going to make much difference, but you will be able to fine tune it even more once you go seq. It will be easier to get it closer tuning batch... like a course vs. fine adjustment..


anybody feel free to correct me if I'm wrong.

 

fixed the fuel problem, it was infact the fpr, it idles at 50 psi and the fuel pressure takes like 30 minutes to drop under 10 psi, not 5 seconds.

as for the injector time, i will datalog it and try dropping the time to maybe 1.4 or so and adjust idle VE settings and fuel pressure.
thanks guys