Hey I have a strange issue that me and my tuner have been working on. The car is running with 1600 injectors, we got the car to idle pretty good still a little erratic, but out of no where the car just shuts off sometimes. Any of you guys ever run into this. It also has the Brian Crower Stage 2 cams.

Thanks

 

need more info. what are you tuning on, is it dying while idling or when coming to a stop, what afrs, spark plug heat range and gap, what is timing set at, and so on?

 

It's a Hydra ECU, yea when its idling the AFR start getting a little erratic I notice its starts to get rich at idle about 11.5-10 then gets lean it’s all over the place. At idle when stopped it will just turn off. It’s a cold plug I want to say 8 or 9 can’t remember the gap or the timing I will have to ask my tuner. I know we advanced the timing at lower range to try and alleviate the problem. I wish we could just raise the idle. Damn drive by wire is a mission.

 

vacuume leaks can cause this. or a stuck open bov. or a bad MAF.

 

Yea seems like a vacuume leak...thing is thats tuff to find fo sho. I will look at bov too...

 

nice font. but seriously, make sure your timing is in the 11-13 degrees range at idle. also does hydra have a idle target base table? if so then you should be able to set your idle at any given rpm range based on coolant temp. this would make alot of sense to look at if the rpms start to go really low as the car warms up. also when dropping 3 heat range units with your plugs your idle will suffer.

 

give this a nice thorough read. pg 128 has some good info on it.


http://www.hydraems.com/Nemesis2.6/H...sersManual.pdf

 

there could be several places that cause that, afr, timing, close loop, rpm surging, cams and vacuum leak. Is your rpm surging? check your close/open look setting make sure its not coming on and off the loop on the idle area.. check the smoothness of your timing and afr map.. then you can try the PID setting on your ISC valve. You can try tuning rich on idle see if it likes it.

 

from what i hear, sheetmetal intake manifolds usually need a rich idle.

 

Hey guys thanks for the comments, however Brett my car runs on E85 does this change things where the timing is concerned. What ECU do you run? How much power have you made so far on your build?

 

It has the decedant racing one, thing idles crappy rich or lean and like I said one day its rich one day its lean its all over the place. I think its the smoothest around 12-13AFR. But now this cutting off thing is a pain in the you know what.

 

How much is you base fuel pressure? I see you have huge injectors try a higher base fuel pressure too maybe 55-60 psi then tune from there.. Mine idles fine 12-14 of timing or even on 16 on E85 but only have 900cc injectors w/ base pressure of 50-55 psi. Like brett said check your intake temp fuel/intake temp spark/coolant spark/coolant temp compensation tables.. those could do a lot. Also how much is your STFT on idle?

 

im running on an aem ems, and have made 419 whp and 366 tq @ 19 psi on an md500 awd dyno. as far as e85 goes, that shouldn't really affect how much timing you should run at idle.

your best bet is to make sure all of your sensors are calibrated correctly, setup your dataloger to view all relevant parameters to this issue, (i.e. timing, coolant temp, volts, afrs, engine load, all pertinent fuel trim tables, blah blah blah...), and then post up some datalog files of when this stalling issue is happening. this would make the problem a little easier to spot if we could see whats going on.

 

you also have to remember that even if you get the stalling issue fixed, you are more than likely to have a pretty rough idle. things like 1600cc injectors, cold plugs, aggressive camshafts, and aftermarket intake manifolds are designed around maximum performance and not comfort. small price to pay for the benefits though.

 

I hear that! Naw i dont mind the rough Idle I like it. Feels like you got a monster under your foot. Its just the stalling man...cant handle that.

 

Why do you have such cold plugs with e85.

Get some stock or 1 step colder in there! 30% more fuel = 30% more cooling....

 

did you teflon tape the ports on the intake mani to prevent leaks? check to see that your maf is tightened down.

 

It’s not for cooling its for high boost applications for like boost blow out at high boost levels. Cold plugs in conjunction with the right gap helps with this. In saying this I don’t think it’s the spark plugs that’s causing the issue.

 

GOD I love e85 more and more each time I read about it!

 

OOO

So you run colder plugs to keep from getting boost blow out. :?