CRX VX mpguino

[Mpgian]

I installed my MPGuino last week and have tried to do some calibration work on it but im having a few issues...

This is on my CRX DX with a 1.5l d15z1 vtec-e (civic VX motor) Crx HF tranny and 195/60-15 tires.

Here is my current #'s
VSS pulses- 7635
Micro Sec/Gal 206229690

My 1st issue is that the distance is correct but my speed according to MPGuino keeps telling me 67 then 58 then 74 then 63 then 65 when Im actually going 60mpg

2nd Issue: this morning after a fill up and reset of the tank (middle and left button) the screen froze on (open source MPGUINO) I had to restart the car to get it to unfreze

any ideas?

[c_rex90]

I'm not sure how this would effect your problem with the mpguino but it would effect your calculation in your gas mileage.

The speed indicated on the speedometer is likely incorrect due to the size of tire you are using. If I'm correct, I believe with the Hf transmission you need to use the stock hf tire size (165/70-R13) in order for the indicated speed to be correct. Either you need to run the correct size tire, or something closer as that size is somewhat hard to find, or change the speedo gear in the transmission to correspond with the tire size.

According to this calculator, with those tires, at 70mph on the speedo your actual speed is almost 77 mph. (passpeedo.com/calculator.htm)
You could probably check this by using a gps to see how fast you're really going, although I'm not sure how accurate they actually are.

So that would definitely be something that you need to take into account if you want accurate readings.

[mcmancuso]

You may want to try the de-bounce circuit addition to the system, it can level out the signal if you're getting too much bounce from the speedo switch.

[c_rex90]

In regards to my previous post, it turns out that honda didnt really care how accurate the speedos/odometers were in these cars so they didnt change the speedo calibration along with the different tire sizes the sub-models came with (Si, Dx, Hf). So its hard telling which tire it was actually calibrated to. However, there should still be some inaccuracy in speed reading since youre using larger tire. Try using a gps to determine your actual speed and how close it is to your indicated speed.