I'm having a problem with the idle pretty much every time I come to a red light , after sitting at a dead stop for about 20 sec the AFR will jump around and it will drop to 20.0 for a few seconds and then will come back to normal with no real issue.

Normal driving is fine but this happens anytime I come to a stop and its only for a few seconds each time. I'm sure its something in relation to those short pulse adders but I don't really understand those, yes I've read all the posts so don't bother relinking me to them I don't get it.

Flow Rate Mdifier is 1.3
My short pulse limit is 1.0msec
Min PW is .102
Short pulse adder from 0.0 to 1.0
0.60156 0.53125 0.46094 0.39063 0.32813 0.25781 0.18750 0.11719 0.04688

I dunno tell me what I need

 

bennyhhr would be able to help you with that. he fixed mine with the tvs.

 

Did u try cleaning ur TB. It works.

 

you might have to fix the base running air flow table (you throttle body blade is closed to much when you stop not allowing enough air in to the combustion chamber)
that is if you havent tuned it yet

 

if that was the case it would happen constantly

 

Have you reset your STFT?

 

no?

what does that have to do with the problem i stated

 

same thing are!


the pcm command 16:1 afr when it happen.

I didnt fix it, dont have the time right now but if you increase the idle to 800 rpm it should fix it.

I find no table for the afr at idle.

 

trims dont have anything to do with your problem. its your short pw adders. sound like you need to add to the pw. you'd need to find a tuner in your area to help you with that.

there is no "table" for idle afr. it can be adjusted in the ol/cl section, but don't go messin with that blindly...

your idle should be 850... if you are below 800 you are way too low for these injectors to stay linear.

 

ya ive never understood the pulse adders, it makes no sense at all, my idle is at 850

 

ya they're a bit tricky. find a good tuner near you and have him see what pulsewidths are causing your afr to go nutty.

 

i need to do this myself

 

it has to do with the relatively large size injectors. Their flow rate is not linear at lower pulse widths (amplified by their relatively large size). They actually flow more in the first split second which is weird but w/e
tuning books FTW

 

Hmm, I'm going to be retuning my car soon since I have the same problem. My question is how do you compensate for the increased pulse width, fuelwise? If I am understanding correctly, being so big, the injectors have trouble injecting such a small amount of fuel (for idle). Wouldn't increasing the PW to a point of performing smoothly also have a side effect of running rich? (when we put the first tune on my car, it would throw rich codes, but was smooth as butter)

I'm new to tuning, so any advice would be helpful. Thanks.

 

I had a problem with my fuel trims being off and making my car extremely lean under most conditions, it seemed to cause that same problem. It may have been a result from the removal of the rear o2 sensor, but i'm not sure. Anyways, I turned off closed loop and STFTs and LTFTs and am going to tune it to my own specifications for the VE and MAF. With a wideband you can set tunes that are more accurate than your cars narrowbands.

mine runs smoother when its running richer at idle, otherwise i usually fluxuates. I'm in the middle of tuning my VE table after that i'm going to use the MAF to adjust for the a smoother idle after the AFR's get in acceptable ranges. I also jumped my idle up to 900 rpm to help smooth it out.

Also, it seems as though that the pulse width adder from the "howto tune 60's" thread work decently well if used.

 

ask ur boy bryan..i gave him my 60's fuel table..he doesnt have idle issues no more