OK, I am looking at the Precision injectors but I don't know what I want. 440cc is the size I am looking at, but do I need high or low impedence?

 

I doubt its your injectors. Uberdata is buggy as hell. What version are you using? Are you burning chips or are you using the ostrich?

If you're burning chips, use the latest version of uberdata 1.7. Are you datalogging to see the exact areas of the map you are trying to modify? If you just go by the column headings, chances are that you are making changes to the wrong portions of the map. The uberdata load columns don't correspond correctly to the load values it takes to reach that column. IMO, its impossible to tune uberdata correctly without datalogging. I won't touch it (especailly at altitudes other than sea level) without datalogging first.

 

I would go bigger than that man. go 660 or better unless uberdata can't control big injectors.

 

Thanks alot for your advice.

I am using the 1.7 version of uberdata, so I don't think that is the problem. I also made a basemap in Crome and it did the same thing, so I don't think it is software related.

I am using datalogging that came with the wideband sensor that shows throttle position and rpm. I partial throttle tuned at 10 in/hg and then at 0 in/hg according to my boost gauge and everything was smooth and running well, but it went super rich on me the next day.

I am burning chips with the Moates Burn 1. I will pick up some more chips and see if the chip is bad. I really need to figure this out because the blue box is really crappy and slow.

But, I do need to upgrade my injectors if I plan on 10 psi. Anything over 550cc would be overkill with the Greddy setup at 10 psi.

 

So, you made a basemap in crome and, with crome, it was fine one day and rich the next?

Its definitely not a bad chip: if you had a bad chip, you would get a solid CEL and the car wouldn't rev over 3100rpms.

Uberdata does not allow you access to any intake air temp or coolant temp correction tables, so you're a/f can definitely change from day to day/season to season..... but if its extremely drastic.... did you change anything on your setup besides the map since then? I.E., fuel pressure, fuel pump, any wiring, etc.?

Here's a thought: does the voltage of your car's electrical system flutuate? Just recently I tuned a car that had an issue with the OBD2->OBD1 conversion which caused the alternator signal wire to be improperly interepreted. The result was an erratic voltage on the entire system and unpredictable times (which can easily cause your problem). I see your car is a 1996 and you're running uberdata (obd1)... what conversion harness are you using? Check this out:

Try that out: check to see if you have a pin at a16, and cut/remove it if you do. See what happens after that

Also, you're going to max those 310's out very quick. As long as you can still idle, there's no downside to running a larger injector... it leaves you more room for future upgrades/higher boost/etc. If you want a direct replacement, get saturated injectors. If you end up runnign peak-and-hold injectors, you'll have to wire in a resistor box (like $5 at a junkyard and its not hard to install)

 

Yeah, it pretty much was fully tuned and running great at 14.7:1 at idle and partial throttle and then it went into 12.5:1 into boost and then the next day, it didn't go more than 12:1 and even at no throttle where it should go completely lean, it was showing 13.5:1. And I didn't change anything at all.

I will try what you suggested with the harness. So, I have to cut the wire on the conversion harness? I am using an SVE harness.

I am definitely going to get some bigger injectors after I get smog out of the way just so I can have the extra room that you are talking about. I also ordered a Walbro 255lph fuel pump just to be safe.

It seems almost as if the ECU is reverting back to stock maps which were never intended for the larger injectors which is causing the richness. It may have to do with the alternator like you suggested. I also ordered another chip just to be safe, but I guess it isn't the problem.

Thanks for your help, I really appreciate it.

 

You can de-pin the harness if you don't want to cut it... its really easy to pop the pins out of the plugs as longas you "open the back door first".... you'll see what I mean.

Post up how it goes.

 

Alright, thanks alot. I have to put the OBD 1 ECU along with the wideband back in, so it will have to wait until this weekend.

I'll keep you posted though.

 

Actually the air temp can scramble a base pattern, I know as I use resistors (yes i am cheap) when I race depending on the weather and temp. cooler days need less fuel. even 5 deg farenheit can make a difference in base settings of an easy 20hp on a tuned system. you need to optimize for different weather patterns and reprogram your rig on race day to those patterns.

 

I had a similar problem with CromePRO and my turbo B18C w/ P28 ECU. While I was tuning my AFR's from 26 in/hg to say 15in/hg would be 15:1. But when I was cruising around in really high vacuum it would read 11:1 or 12:1. But at that point my vacuum was higher then 26 in/hg. 26 in/hg was the highest vacuum column on my Crome fuel map. So I thought it had to do with my actual vacuum being out of the range of my Crome fuel maps highest vacuum column.

Maybe if you rescale the vacuum columns so that the first vacuum column is 28 in/hg or 30 in/hg you can actually log and adjust the AFRs for the really high vacuum columns? I haven't gotten a chance to experiment with scaling vacuum columns in CromePRO yet to see if it will work. But maybe you should give it a try.

Look at your vacuum gauge and when it starts reading rich when you are in high vacuum make a note of what your vacuum gauge reads. Now look at your fuel map and compare that with your highest vacuum column. Post up what your vacuum & AFR numbers while actually driving and your highest in UD.