After I changed to SVO #30 I cant get my car to idle in closed loop.

Fuel pressure is set at 38 psi and chip is stock APYU. (Want to start from the beginning)

I first thought I had a big vacuum leak but the car Idles smooth when I unplug the MAF......

The idle s goes up and down a few times then it dies so I can get much useful info from the scanner....

Any ideas where I should start to get it idle so I can start tuning it.

Mods in sign.

Thanks/N.

 

30# SVO injectors with a stock chip? No way dude. You need a custom chip for that. In any case - this has nothing to do with DIY PROM programming.

Tim

 

I know I need a custom PROM thats why I'm here.....I have burned some EPROMS for my car earlier but wanted to start from scratch with my current setup........

But I have to start with something and that is APYU.bin but the car wont idle with it so I can se how rich it is.........I'll burn some PROMS tonight and se if I atleast can get it to idle so I can read BLM's and so on.....

Just looking for hints where to start......I have alot of tuning ahead of me.....

 

Well, you did not state wheather you changed the fuel injector constant to 30.0 in the stock Eprom. I assume that when you say that you started with the stock APYU Eprom, that the injector constant is the GM stock constant. This will not work well from the get-go. Anyway, just my opinion.

 

what i have found using the 30 lbs injectors with the stock prom is that there way too much. They (bottom) out the block learns to like 100 (as far down as they go) and the 02 sensor is still reading rich. It should start well in the mornings though lol.

 

I have changed to inj.const to #30 and I still coulnd get it to run, but I found out why....bad O2 sensor switched it yesterday and it now runs.........BLM is at 117....hopefully I'll have time to tune this weekend......

/N.

 

the car should start with the o2 sensor disonected, because when its cold start, there is no signal whatso ever from the 02 sensor. 30 lbs is really too big for normally aspirated engines, unless you can crank the fuel pressure down to 20-30 psi. unless you had a chip burnt with less ontime calibrated to the 30 lbs 117 in the 1st block learn dosent mean much, you need to check around #6. running that rich cools the 02 sensor at idle and gives false readings.

 

I never had any starting problems......the problem was in closed loop at idle.......It idles "fine" in limp home mode.....but that problem is solved it was a bad O2. Now its tuning time!

newest change are:
FP to 42 PSI and inj.const to #32.

I'll try the PROM this weekend.......

 

You have absolutely no idea what you are talking about. 30lb is not too big for normally aspirated engines ... unless your car is really slow. I'm running 30's on my engine and I know others that are running 30's too. Why? Because we need them because the injector duty cycle with smaller injectors is too high.

Tim

 

dude, thats what i said, the on time is too long on a stock chip for 30 lbs. what cant you understand about that?

 

Wow - it's not too often I say this. Sorry dude. Somehow I screwed up reading your post.

Tim

 

its cool dude, i ran 30's in my Iroc with a 427 ci sbc and they were still too much with the stock chip.