dizwiz24

Does anyone know how to fix this?

The exhaust at idle smells pig rich and makes me sick to my stomach.
City fuel economy took a dump too. I get 13 if im lucky.

While driving, I dont notice it as much. The car feels good performance wise too.

I have a 93 hotcam'd 6speed LT1 with ported heads LT headers, no cats and heated 3 wire o2 sensors.

tjwong

It sounds like the VE tables are off in the idle regions. But its very hard to diagnose for sure unless I can see it to see what the ECM is doing. If you can get some scan tool datalogs that helps a lot to identify the issues. If you call Ed I am sure that he can remedy this for you but he may ask for the same information. Sometims thats the hard thing about mail order tunes. If you were close to me its a fairly easy remedy to fix once I get my 4 gas analyzer on it and or a wide band. I can burn a chip pretty fast based on what I see on the instruments.

dizwiz24

quote: It sounds like the VE tables are off in the idle regions. But its very hard to diagnose for sure unless I can see it to see what the ECM is doing. If you can get some scan tool datalogs that helps a lot to identify the issues. If you call Ed I am sure that he can remedy this for you but he may ask for the same information. Sometims thats the hard thing about mail order tunes. If you were close to me its a fairly easy remedy to fix once I get my 4 gas analyzer on it and or a wide band. I can burn a chip pretty fast based on what I see on the instruments.



Thanks for the response tjwong. If theres one person I know has experience tuning here...I know its you.

Ive supplied Ed Wright with countless auto x-ray plots at WOT (of course that would prob only help him fix WOT problems).

Ive also sent the chip back to him at least 4 times to no avail.

Is this something that has to do with the IAC valve? or you say VE tables?

IM thinking eventually I should buy the equipment, cable, etc. start burning my own chips.

Z06_BluByU

I had a similar problem with my reprogramming mail order chips.. but I used another chip burner than ed.. anyhow.. I solved the problem just like you suggested.. I bought all the equipment and burned my own chip... tjwong, ski and guys like me that have limited experiance were/are very helpful and help me overcome any road blocks i faced! got for it.. you'll be frustrated but will enjoy the end result

93Blackrose

Do you have Datamaster? if so, what are your BLM's at idle? When I programmed my chip I had to remove alot of fuel from the VE table compared to stock. Also, if you have a copy of your BIN file, email it to me and I'll trim out some of the fuel in the idle region and then smooth the table.

93 ragtop

I have the same problem. My tuner does not believe there is a problem with the tune but with the car. I sent him a scan with my auto x-ray but I have not heard back from him on this. Before sending it he did tell me that the auto x-ray scans were not enough to tune by but send it to him anyways. I have ordered a cable for datamaster. So hopefully i will get some better scans with that.
My custom chip makes less hp 343 compared to my ed wright generic chip 356 hp. and it runs 1 to 2 tenths slower in the qtr with the custom chip. I to feel it is very rich at idle. My blm's are very low. At a sustaned speed of 2300 rpms to 2600 rpms in neutral they are 108 to 117.
I have another member who has e-mailed me and he also has a 93 with a very similar set up. He ended up with a ed wright tune and is very happy. Hopefully he can work it out for you.
By the way, you can purchase the cable from andy at akm electronics for 95 dollars and get 20 free scans with data master. Thats the path Im heading down.

99svrcpe

Sounds like a similar problem I had with a Ed Wright tune. My car was running very rich all through the rpm band (surging idle, stumble, knock retard,fauled plugs) after numerous emails with datalog numbers they characterized my problems as mechanical. So I decided purchase my own LT1 edit program, and low and behold, they had my computer programed for 60# injectors instead of 30#

Nathan Plemons

Diz, if you've got provisions to burn your own chip I could easily send you the BIN file I use. If you don't I would gladly burn you a chip free of charge if you just buy the adapter and chips.

You can go to www.moates.net and buy the GP1 package. This comes with an ZIF style adapter and two chips. Send me the chips and I'll burn you chip guesses, 2 at a time until we get it right.

Odd are it won't take too long though because my Hot Cam tune is actually pretty darn close to right as it is.

tjwong

No it isn't the IAC valve, its the fueling in the VE tables. I don't have an Auto X ray device. I can read datamaster files without any problems. One thing I may ask, and that is.... what makes you think its rich? Sometimes on cammed up cars, it could be lean. And if its lean enough it could have slight lean misfires and the smell from the exhaust when this happens is very acrid and one would think it is very rich. The reason is that when the mixture goes lean beyong a point, the mixture can no longer burn correctly. And what you smell is the raw hydrocarbons out the tail pipes, and let me tell you it could be very rude.

I had a car in the other day, in fact it was a forum members brothers car. It did that very exact thing. A wide band told me right off that his car was running in the 15.6 to 16.5 AFR at idle. Once I brought the AFR down to 14.5 the smells went away. If your fuel trims are running in the 150's then its lean, if its running below 120s then its rich, on the extreme side of things it would be 180 and 108 which I believe is the limits to the amount of correction the ECM can make. Once it hits the pegs it can no longer correct for either condition.

mos90

Ive supplied Ed Wright with countless auto x-ray plots at WOT (of course that would prob only help him fix WOT problems).


the autoxray scanner will not read your afr at wot. ecm goes into open loop. you can look at your o2 sensor readings but that not very accurate. wideband is the best way to read wot. i had to buy a wideband for that exact reason. im not sure if datamaster can read at wot either, but someone thats used it could tell you that.

RVY

Had the same problems with my '93. Difference in cams and larger injectors created a problem with what is/was called afterstart/warm up enrichment. I gave up with other people burning me chips and purchased a DFI (late 90's time frame). I wasn't too pleased with your chip burners program. The low to midrange horsepower difference (dyno) between his program and hypertech was significant.

GulfCoastEagle

If you don't mind sharing.

rgstrick@hotmail

THX