Hey guys. I've been through as much reading as i can handle over the last few weeks between eectuning.org, eecdynotuning.org and articles here trying to make ends of this. Where are you reaaaallllllly truly suppose to begin tuning your fuel and idle? Everywhere I see says "you can't dial in fuel unless you're at stabilized warm idle." And then i see stuff like, "you can't adjust idle until your fuel is dialed in." "Make your lambses match your maf lalalalala".....How does one achieve stabilized warm idle if your RPM's are surging and your AFR is bouncing around? I can't keep a consistent idle unless I'm at about 1100 rpm. Hoping to come up with a better strategy to attack this with.

While driving i can get the AFRs in a safe range 11-13, it's really just trouble at low rpm. I can't tell if it's fuel, timing, isc settings(haven't found a good writeup) causing my surging problems. No vac leaks etc...

Gt40p 306, gt45 turbo, 36lb, hpx slot maf, 255lph, tweecer, a9l, typhoon upper/lower, all the little boltons too. Still using calcon and caledit too so jeep that in mind.

 

What cam do you have?

 

Its the ford B cam. Base timing is set at 12 right now, I haven't pulled any timing except above .75 load so the idle parameters are untouched for now. I'm seeing about 18-21 inHg.

I noticed last night when I pulled the pip to verify the timing again that it seemed to settle down a lot. Should I try leave it locked out for now so I can dial in my fuel with out the ECU throwing timing around?

How about the idle air? Most base idle reset procedures I see tell you to disconnect it while adjusting, but what do you guys do? Anyone have a good write up on isc settings? I see people mention dashpot etc but it doesn't actually seem they understand the values or related functions involved, just throwing around numbers.

I'll work on getting some logs posted today if I get a chance.

Thanks guys!

 

I cant speak for the B-cam, but on my F-cam, All I did was raise idle speed and minimum airflow and that was all it needed to idle decent. Make sure your MAF transfer is spot on, and your injector breakpoints are right as well. Fastest way to dial in the MAF transfer is disable closed loop and adjust MAF transfer until the wideband reads commanded AF ratio at several points from idle and up. Remember, the MAF transfer has to be right before you can accuratly adjust fuel in the fuel tables. If the timing tables are stock, they should be good enough to get idle close.
Can you use Binary Editor? Just a thought, but Binary Editor calculates MAF transfer for you(well, kinda).

 

ALso worth mentioning., I will assume you are using your MAF in a blow thru manner; Make sure there is at least 8" of straight pipe before the meter. The more the better. If you have the meter too close to a bend it makes them REAL hard to tune, if not impossible.

 

Lock idle timing. then adjust fuel. If it's surging, then it's probably lean. Get it idled out, then go back and put in a timing curve if you really want.

 

^ Yeah, seems lean. My Fcam 351 turbo car won't idle above 13.5:1 AFR without surging.

 

Thanks for the tips guys. The maf positioning occurred to me too, it has about six inches straight in front but coming from a 90deg out of the intercooler. I could try clocking the tube a bit. I don't really have any other straighter sections I could move it to. I feel like the kg/hr was fairly consistent when it wasn't surging everywhere. I didn't pay super close attention to the load nums though

I have a few logs but I didn't do a good enough job organizing them by what parameters I changed etc, so a few days later I can't tell you what's what. I'll get new ones by this weekend where I'm not screwing with things constantly so we have less vars involved.

In the meantime this evening I'm welding on some dynomax bullets because I ditched the flowdisasters. I also have to pull my headers as I blew the gasket out the bottom of cyl 1 making a little 4-5psi pull the other day. Exhaust back pressure hadn't occurred to me so much when I first started fabbing this up and bolting it together. Then I start seeing posts about header gasket hell and most people only use copper rtv haha. I bought some cometic mls gaskets now so hopefully those fix that. I don't know if my crossover will line up happy if I lose the .030 on each side and ditch the gaskets altogether, so we'll try this for now. So little time with work and two kids under 3 yrs old haha

 

Oh, and what are some good breakpoint numbers to try for the 36lb ford racing injectors? I've seen conflicting advice and numbers on breakpoint settings