Subject: Re: Digi Dash Tachometers & Repair by CFI-EFI on 2009/5/29 15:32:27
Quote:
CentralCoaster wrote: I can answer your question with more questions for someone else.
Is the slowness related to the slow computer?
Would an ECM upgrade help?
Has anyone even upgraded the crossfire ECM to the faster unit?
I also wonder if the problems in the upper rpm could be related to the tach filter (if you have one) or the distributor. Sometimes my tach sort of stalls at higher rpm, but it doesn't go haywire. Typically though, cross-fire (pun intended) in the ignition causes the guages to go screwy anytime the car is running, at any rpm.
Anyhow, I think even a fast digital guage would be still be useless for anything but normal driving, and your 84 guages are even less clear to read at a glance.
For racing, a shift light is precisely what's needed and nothing more. I use that on the roadcourse and dragstrip and don't look at anything else aside from the oil and water temp guages. Assuming your tach filter and distributor are working fine, you can just tap a shiftlight into the tach wire and still hide it cleanly in the vent to keep the car looking stock.
For normal driving, I just look at the numbers. I did however redo my dash color gel so the tach bar turns from blue to white at 3500 rpms and to red at 4500 rpms. So I guess that helps a little bit.
I don't know that a faster ECM would improve the the tach. This is a common complaint from digi dash owners of all years. I think the tach signals are processed in the dash and not the ECM for display purposes. There are ECM conversions done to the Crossfire to the TBI pick up truck computers that are easier to change the programming on.
A few years back when I broke one of the wires off of my tach filter, I bypassed the filter. It has worked great until just recently. The distributor seems to be fine. The goofy, infrequent speedometer reading seem do come only after a fairly hard bump. It reads "288" as if all of the elements of the LCD display are activated. The tach seems fine until over 5000 rpms. Then it displays nonsense, random numbers. The causes and the effects are both different for the tach and the speedo. They appear to be unrelated. I have no problems with any of the other readouts.
A shift light would definitely solve the one issue, but I would still like to monitor my engine speed.
Do you know of an economical shift light? Wasn't there a Corvette owner building them as a sideline? Your colors and gels are way beyond me. Thanks, and...
