'97 Chevy Cavalier Install and Questions
 

I just wanted to start a post about my recent install in my Chevy Cavalier with a 2.2L engine and had a couple questions.

First off the install went great! The details on the forums here about hooking everything up are excellent and I was able to very quickly find my VSS and Injector wires (having the factory service manuals helped a lot). I installed a preassembled unit from dcb in my car so there were no issues with building or quality of the components at all. I had bought the unit almost a year ago and just now got it installed because I wanted the install to be just right and in a proper enclosure. I've only done one fill up so far since installing the unit so it is nowhere near zeroed in yet as I'm just doing guesstimates based on injector size at the moment. Overall I'm very pleased with the unit!

Now the questions...

If I understand correctly the numbers on the LCD should never turn off? The back light does time out based on the time out setting but the numbers never go away. I think this is right...?

On the Tank page... the average speed for the tank is always being calculated. By this I mean even after the car has been sitting engine off/ignition off the MH figure which is the average MPH for the tank is ticking down. If this is the case won't this give me an inaccurate average for the speed for the tank? Anytime my car is parked it's going to be continuously counting down towards 0.

If I read the calibration instructions correctly the Current Mileage page should freeze once the unit times out. I've noticed after a couple trips getting back in the car after sometime and the current mileage is reading 9999 before starting the car back up. I thought this figure didn't change until the car restarted after the unit when into it's time out mode.

I guess most of my questions are related to the time out function and what should be occurring and if the unit is continuously calculating during the time out as well. I know for some users the time out is important because of using engine off cruise so they will want it to keep calculating when the car is not running. In my automatic I never shutoff and glide in neutral as I've read it's bad for the transmission so I have my timeout set to about a minute.

My last question is how much power does the unit pull from the battery? Are we talking maybe a few hundred milliamps? I'm in the process of moving so my meter is locked away in a storage unit unfortunately. Would just be good to know so I can pull the fuse if the car is parked for maybe more than a week or so. Also, I'm assuming if the fuse is pulled all memory and all settings are cleared correct? Not the program itself but just the user defined settings.

I was also wondering if anybody has a link to tips to dialing in the best economy with one of these gauges. I'm sure there's something already out there.

Thanks for your help and sorry if some of these questions have been asked. I searched a bit but was having some trouble finding detailed answers to my questions. I'll be sure to post some quick pictures later.

Hey glad it went well.

re digits: always on, but the backlight will go off to reduce power/conspicuousness.

re tank page: it's a little complicated, but the unit will go back to the instant in time of the last activity (button press or injector/vss pulse) when it wakes up, assuming it has not seen activity for a while. Really the only thing that would have changed is elapsed time however, so the tank mph might jump back up when it wakes up again. Any lapses in activity less than the timeout period will count against the mph.

re: current, hmm. not sure, sounds like it got a vss spike somehow. Doesn't sound like a huge deal though, would keep an eye on the tank distance/consumption though just to make sure its accurate. It may be some permutation of a low timeout value, dunno.

Unit pulls 20 milliamps with the backlight off. 40ma on low, 60 on med, 80ma on high.

re: tips, here is a general start 100+ Hypermiling / ecodriving tips & tactics for better mpg - EcoModder.com look at your instant and average and try to figure out what works basically. The main thing is that you are now able to get feedback sooner than waiting for the next fillup.

For the tank page I went out to look in my car and it's no longer ticking... I think when I noticed that at work yesterday I had pushed a button when I was flipping through pages to check the odometer readout. The odometer is spot on.

20 ma with the backlight off is nothing. I think I will disconnect though if I leave it for longer than a week. I do lose all of my user settings if I disconnect it correct?

I've read through the 100+ tips several times and do my best to incorporate them when I drive. I think the biggest thing I'm looking for as far as tips goes is how should I determine the best pattern for acceleration? I mean I can accelerate incredibly slow and that keeps my Instant MPG readout as high as possible through the acceleration but that measure is very low compared to what I get at cruising speeds. So if I'm taking forever to get to cruise speed I'm going to hurt my overall average it seems like. I know there's a happy medium between accelerating too slow and accelerating too quickly and was hoping this gauge could help me find that sweet spot for my acceleration. Unfortunately I do a considerable amount of city driving so really zeroing in that best acceleration is going to be my best chance for improving economy I think.

Thanks again for the help! As soon as I get enough posts I'll put up some pictures.

You might consider a 5 watt solar battery maintainer from Harbor Freight (as an example) for those times when the car will sit parked. It plugs into the cigarette lighter and should easily outrun the couple of minimal draws on your battery.