Gregory VanLare

I have an 85 and when I put my auto x-ray on it is usually in open loop. I've been getting a couple of SYS lately (high voltage and ESC) they come and go. Now that's it's been getting cold, I see the SYS in the morning the light flickers for 8-10 minutes then goes on solid (high voltage) and the car is running rough. Then all of a sudden it goes off and it's like someone flicked a switch and the car just picks right up! I've been watching the gauge for voltage and it runs from 14.2 -14.5. This should be in range the book says you get a code at 17? Well, when the gauge goes down to 13.8 I suddenly notice that it's going into closed loop!!! If the gauge goes higher it will go into open again! What should I do to address this?? Would this be the ECM or is it a short or loose ground? I'm stymied! I'm not a great mechanic but I've correctly diagnosed other problems (of course I've gone to the garage to have them fix it an verify my diagnosis). I can't afford to take it to the garage and have them do the trouble shooting! I first thought it was the auto x-ray because I've seen posts indicating it doesn't communicate well with the 85s but I'm not sure what the issue is?? I don't want to ***** nilly begin to sink a ton of money into it replacing parts that don't need to be replaced! Any suggestions?? :confused: :confused:
I'm also running rich when in open loop and lean in closed!


[Modified by Gregory VanLare, 10:07 PM 10/10/2003]

ErnieN85

I'd like an answer to this one also. I can't seem to get closed loop either (85 also) I too have a rich flag set. My prom id is 61 and I'm told its an early issue maybe that is the problem. also as a point of interest i've had to up the Fuel pressure to 44 from 34 to eliminate knock retard and get the o2 sensor readings to 880 mv at WOT. I hope this give you some help BTW 14.2 volts is fairly high but may be required if the battery is badly discharged (bad battery)

88_vette

14.5 seems abit high from normal. I run at 13.8 according to the guage, but it's a little off. I hooked up my fluke and it reads 14.00 volts all the time.So with that said it is possible you are running around 14.7. Have the alt tested it's a free thing and cost you some time.


AS far as the fuel pressure thing you most likely have a bad fuel pump and by upping the pressure you have over come it's lack of ability to flow enough fuel to keep the right pressure. You need to check BOTH pressure and flow rate. rate should be 1 pint or more in 15 seconds. This can be done by undoing the fee line from the fuel rails and hooking up a hoes running into a gas safe container. Run it for 15sec. and then measure how much came out. Pressure you will have to hook a hose to this line as well, but you will have to use a univ. fuel pressure guage not the one that screws on the little fuel rail valve.

ErnieN85

In my case it's not the fuel pump. it's new and hold presure fine. we ran it at WOT with a gauage on the fuel rail (on the road). possiblt it's because the engine has a few modifications (not much) bigger throttle body, and bigger valves. the cam is suposed to be stock, but i haven't checked it and before the modifications I had the same lean conditions at WOT

Gregory VanLare

I too replaced the fuel pump (and the sending unit because it was badly corroded and whew pricey!) My O2 fluctuates but goes up over 800 so I assume that's fine. Where do I go to have the alternator check? I'll do it tomorrow if possible, I want to get it running up to snuff before the snow flies and it gets put away for the season! The other error code I get is Missing CalPac. I know it's there! That's why I question the ECM. I did have a chip burned by our moderator! a couple of years ago. It runs a thousand percent better than when I got it but still not where it should. :eek:


[Modified by Gregory VanLare, 7:44 PM 10/12/2003]