Can't get to idle cold - 720CC RC

Sexwitharex · Post by **Sexwitharex** » Fri Jun 12, 2009 9:13 am

Maybe someone can help me with this since it's driving me crazy. I have a D16Z6 that I had no problem getting to idle with 560cc Evo 8 injectors, stock manifold, and stock TB. Since then, i've bolted on 720CC RC injectors, Venom manifold (adapted IAC), and a 68mm Skunk2 TB, and now I can't get the engine to idle when cold for the life of me (way too rich â€“ fouls out spark plugs).

I've tried decreasing the values in the first 3 columns, playing with the IAT correction and ECT correction â€“ but no matter what I change, if I can get it to idle correctly when cold then as soon as itâ€™s warmed up Itâ€™ll start leaning out too far. Is there a strict cold-idle enrichment setting that Iâ€™m missing? Thanks in advance...

Post by **calvin** » Fri Jun 12, 2009 9:59 am

ect & iat correciton is most important for cold weather. Post cal and log please

Bindegal · Post by **Bindegal** » Mon Jun 15, 2009 4:08 am

I would take a good look at the battery compensation tables also. Especially on cars with a relocated battery and even semi-large injectors, I find that AFR can be very unstable. For 550cc and above, I usually fine tune the battery comp table manually; this is best done when IAT and ECT are \"neutral\" so their repective compensation tables are 0. This is not to say that there is any fault as such with the battery comp values we have for known injectors in the software. ItÂ´s just that every car is slightly different. /Allan

Sexwitharex · Post by **Sexwitharex** » Mon Jun 15, 2009 9:07 am

Thanks for the tips - I'm still experimenting with the ECT tables - haven't screwed with the IAT because that tends to lean out the whole map when I do. I do have a relocated battery - and I have noticed drastic changes in AFR when I put my headlights on due to the voltage drop. As a result I've also been playing around with the battery tables and have gotten it to richen slightly instead of leaning out like it was doing originally. These injectors are a much bigger PITA to tune than the 560's I had in there before

I've also noticed that my engine starts to develop an intermittent misfire when running 13 AFR and above at idle. I just did a full ignition tune-up, including gapping down to .28, so i'm not sure what this can be... As of current the engine has a low/poor idle, and the AFR varies too much to get it away from the 11's in fear of leaning out. It also doesn't seem like the target idle and IACV duty cycle settings takes affect until the ECT is above 170F or so - don't know if that's just me, though. I'll play some more, and if I still can't figure it out I'll post the cal and log as requested. Thanks again

Post by **calvin** » Mon Jun 15, 2009 10:55 pm

Sexwitharex wrote:Thanks for the tips - I'm still experimenting with the ECT tables - haven't screwed with the IAT because that tends to lean out the whole map when I do. I do have a relocated battery - and I have noticed drastic changes in AFR when I put my headlights on due to the voltage drop. As a result I've also been playing around with the battery tables and have gotten it to richen slightly instead of leaning out like it was doing originally. These injectors are a much bigger PITA to tune than the 560's I had in there before I've also noticed that my engine starts to develop an intermittent misfire when running 13 AFR and above at idle. I just did a full ignition tune-up, including gapping down to .28, so i'm not sure what this can be... As of current the engine has a low/poor idle, and the AFR varies too much to get it away from the 11's in fear of leaning out. It also doesn't seem like the target idle and IACV duty cycle settings takes affect until the ECT is above 170F or so - don't know if that's just me, though. I'll play some more, and if I still can't figure it out I'll post the cal and log as requested. Thanks again

if you have a afr drop with headlights/elec load tune bat tables. try running richer at idle to prevent mis fire some cars like a rich idle

DSMR · Post by **DSMR** » Mon Jun 15, 2009 10:59 pm

In my experience, the lower the gap in the plug, the harder it is to cold start.

Post by **Bugermass** » Wed Jun 17, 2009 12:08 am

RC750 are the worst injectors ever made.. Throw them away and get somthing different.

patrick_yi_82 · Post by **patrick_yi_82** » Wed Jun 17, 2009 1:16 am

Bugermass wrote:RC750 are the worst injectors ever made.. Throw them away and get somthing different.

I will happly let you trash my house with that injector. When I upgraded my injector to 550, it ran like a broken disel truck until the battery compentation was corrected. It was really delicate, so a slight change in the number in IAT, ECT or battery made a huge change in the car drivability. I almost got into an accident in the morning, because the lean protection was activated when IAT was low and the fuel wasn't compensated enough.

Sexwitharex · Post by **Sexwitharex** » Wed Jun 17, 2009 9:43 am

Bugermass wrote:RC750 are the worst injectors ever made.. Throw them away and get somthing different.

They're 720's - but I'm sure they're probably the same thing. What brand injector and size would you recommend for a D16Z6 with room for 425HP? I had DSM 440's and 560's, Delphi 680's, and now these RC's (which were flow tested and cleaned, btw). The RC's are definetly the most menstrual.

non-vtec · Post by **non-vtec** » Wed Jun 17, 2009 9:19 pm

nothing wrong with rc720-750cc injectors. just because you cant tune them within a couple hours it does not make them a bad fuel injector. they do require quite abit of time to get to idle/run smooth.

Mad Scientist0001 · Post by **Mad Scientist0001** » Wed Oct 07, 2009 1:34 am

A little late but This Is the values I got with the rc750 Sat that works good for me 24.v,15.99v,14.16v,12.04v10.01v,8.09v,5.63v 1.32,1.32,1.87,2.53,3.64,5.63,5.63

combz · Post by **combz** » Thu Oct 08, 2009 10:45 am

i have rc750s on my d16y8. i selected them from the get go when making my cal,everything seems to be peachy, i had no trouble getting the car to idle.

Post by **Bugermass** » Thu Oct 08, 2009 12:46 pm

non-vtec wrote:nothing wrong with rc720-750cc injectors. just because you cant tune them within a couple hours it does not make them a bad fuel injector. they do require quite abit of time to get to idle/run smooth.

I don't like having to bandaid poor spray pattern with extra tuning time. There are so many other quality injectors out there I rather just use a better injector.

92bluepreludesi · Post by **92bluepreludesi** » Tue Nov 17, 2009 11:02 am

hey did you ever figure out how to fix your problem? having a similar issue. people seem to have tuned off topic.