crazy tachometer

I'm having a problem with the tachometer in my speedster.
I am on the 3rd one and each time I have the same problem.
After installing and correctly wiring (according to the wiring diagram sent by Kirk Duncan) the tach works fine for about 10-15 minutes of driving and then it starts jumping all over and shows
rpm readings that are way too high.
Kirk has sent 2 replacements and both have done the same thing.
These tachs are Chinese knock offs of a VDO and maybe they're
just no good .
Has anyone else had any problems with the tach in a Vintage Speedster.
Mine is a 2002 turnkey model. Thanks, Bill

Bill,

What ignition are you using? If it's a stock coil and distributor, then . . . maybe score a tach with the stock 914 mechanism inside.

If it's other than that, try replacing your ignition with stock components as a test, just to see if the tach is receiving/translating the signal from the coil correctly.

If you're using an MSD box, they have a wonderful tech line and a designated installation/troubleshooting section on their web site that's very complete. It's a series of downloadable PDF files so that you can make up your own booklet if you like.

Either way, a little work, but worth it!

Luck,

TC

Electronic ignition needs a tach filter

Bill that's a perennial problem here...search under "Jumpy tach" in the forum search utility and you'll see what I mean. I have the same problem and it comes and goes; I chose to just ignore it. Chinese junk!!!!

I have the china crap tach & gauges also, so far no problems with tach*, even with the use of electronic ignition. Even so, I dont discard the possibility that it will start jumping like the rest, I've heard this story many times. So if you can, get the VDOs from brazil, later if you can please let me know where you got them from and at what price...

Update: My second one just died too. The one that the car had straight from the shop never worked so Kirk sent me another one that worked erratically for close to 2 years. I already emailed him to see where I can get it repaired or get a replacement.

I ended up sending my 914 VDO Tach to Palo Alto speedometer. The electronics were upgraded to work with the Mallory electronic distributor. Cost around $230 ouch!

When I went to pick my speedster up 12/05,the tach was erractic for a couple of hundred miles or so and then seemed to fix itself.You may want to just drive it awhile and see if yours fixes itself too.I was told that they've had a lot of problems with those tach made in china.

Well Joe; this is actually the second one in my car. The one that it came from the shop new wasn't working so Kirk sent me another one; I installed it and sent the other one back. This one worked fine for a while, then started working erratically and finally died last week.

Ricardo,how many miles did you get off the replacement????And what brand ??? are you going to replace it with???

I got around 3,500 or 3,600 miles out of it. I emailed Kirk last week asking where can I get it fixed or if I could buy another one from him but haven't received a response from him yet. The brand Vintage and JPS are using is West; a Chinese repro of the Brazilian VDO 356 repro. I know for a fact that Carey Hines from Beck still carries the Brazilian VDO's; a couple of years ago they were standard issue on Vintage and JPS but these manufacturers decided to get them made in China...not a smart move from a reliability standpoint (although probably much so from an economical one).

Funnily enough I was driving the car today and it started working again albeit very erratically.....it's almost non-functional.

I've emailed Kirk about 3 times and he hasn't reponded.Let me know what happens.

My car was completed about six weeks ago and I'm having the same problem with the tach. It reads way to high and jumps around. Kirk told me he's been having problems with these tachs and said he expects a shipment of new ones soon. From all the postings here I wouldn't get my hopes up on actually getting a tach that works worth a damn if it comes from China. You'd think for the money you spend on these cars that everything, and I mean everything, would work properly.

I think the makers know we are willing to accept what we get as long as it's not a real major problem.It seems we are told to expect some bugs in these cars,not from the makers but by other owners.So we put up with it since we want to own one of these puppies.If these were Toyotas or any other name brand car,we'd be back at the dealership pissed off because our gauges didn't work or our tops leaked when it rained or any of the other problems buyers of these replicas have.After I picked mine up and drove it for a few hundred miles I brought it back with several issues including the tach ,I was told that they were all bad....Luckily my tach fixed it self soon after,who knows how long it will work.My gas gauge was terribly off too,but I ran out of gas the other day and it seems to have adjusted itself...go figure???All in all it's a neat little car to drive.

You can order a nice new VDO tach from any of the usual suspects and just swap the guts into the crummy 356 repro tach housings, using the faces, pointers and everything else.

It's Easy Peasy. Looks like the other repro gauges, but with genuine, accurate VDO internals. No muss, no fuss!

TC

TC's idea is good, Ive thought about it before, the problem is opening the Tach. These china gauges as well as the VDOs are sealed. You have to pry open the bezel to get inside, and this procedure requires carefully beding it. It can be done but if not done right it will look like your dog chewed up your gauge (like someone else said). There might be other fitting or scaling issues. Im waiting for my china-tach to die to try this with a 914 VDO tach I have and see what happens... If somebody tries it let us know the results... cheers ~jJ~

Not sure about the China-Made tachs but I'll betcha they're a lot like the cheapo "Sun Pro" gauges around here. Just gotta be a little patient with the bezel. The VDO tachs are a breeze to open. Make a tool out of your screw driver. The blade needs to be about 0.35 wide, with about a 10 degree angle ground into the end. About as sharp as a dull steak knife.

Work the bezel off by prying around and around the edge carefully with this little home made tool. A few times around does the trick. Pop off the bezel and use the end of a small open-end wrench to smooth out the "crimp" marks and open it up further to make the re-assembly easier.

When you re-install the bezel, use the back of a spoon to bend/crimp the edge over the lip on the tach housing. The back side of the spoon is perfectly rounded and smooth and nicely spreads the load over a decent area so the everything goes pretty smoothly.

I've opened almost every gauge that I've picked up. For cleaning, spyder removal, bezel replacement/repair, or face change and such. It's honestly a snap! (The Autometers are the easiest of all, because the bezels are soft aluminum . . . but the VDOs are almost as easy)

Luck,

TC

Or . . . just buy these!

http://www.thesamba.com/vw/classifieds/detail.php?id=283331
And maybe this little charmer to go with 'em:
http://www.thesamba.com/vw/classifieds/detail.php?id=283259

Those are really nice but if I recall correctly the tach on 356's is mechanical and not electrical like on VW's so that takes us back to square one. In my case the tach is the only culprit; I don't have any complaints about the other gauges.

all of this talk on crazy tachs makes me want to chime in ask what is the best way to test a tach. Mines doesn't bounce, it doesn't do squat. I am not sure that it is wired properly, but I also don't want to send it to get repaired unless I know that it is in fact shot. What is the best way to make sure that the wiring is done correctly and to make sure that the wiring is not cut somewhere along the way or grounded out? The wire coming from the coil to the back of the tach in the same colour, but I am not so sure that it is connected correctly or if it is bad? It is a german made VDO (or so it says so on the back). Thanks in advance.

Tachs are kinda universal. It's almost as though they were designed that way.

Green goes to negative coil.
Red goes to 12 volt, key on.
Black goes to ground.
White goes to light switch.

On a VDO (914) tach, if there are only tabs/spades rather than wires. From left to right . . .

+12 goes to 12 volt, key on.
+6 is a dead or missing tab/spade.
1 goes to negative coil (1 on the coil is negative, 15 is positive).
- goes to ground.

Easy Peasy,

TC

No word from Kirk yet.

TC; I've been checking the new VDO gauges for VW's to see if I can retrofit my China gauge with the VDO innards. The new VDO's are about 1" smaller in diameter that the China gauges; I imagine that would affect the accuracy of the reading wouldn't it?

No silly.

If a tach is calibrated for 6 grand, or 7 grand it reads accurately to that RPM. If the numerals are one inch from the center of the pointer or one mile from the center of the pointer, it's still calibrated for 6 or 7 grand.

That's like saying that the horn ring turns faster than the outer ring of the steering wheel. The steering shaft turns 3 revolutions lock to lock regardless of how far your hands are from the center.
Obviously the linear travel will be different, but we aren't talking about tire height, we're dealing with RPMs which are constant regardsless of the outer diameter, gauge face or steering wheel or tire.

As long as the two tachs have the same maximum RPM calibration, you're fine.

Ok; thanks for the explanation; now I have a clearer perspective. I sent a couple of e-mails to North Hollywood Speedometer and Palo Alto Speedometer to have an idea of the cost involved in such a repair or retrofit (it's probably better to stuff in a new VDO tach and forget about it). I'm still pondering whether to take the plunge and do it myself. I'll probably be convinced after getting a couple of estimates from the pros.....it's probably not going to be an affordable price, regardless of whether it's an Oriental piece of sh*t or not.....

Ricardo, just remember that China-crap and VDO differ in diameter. China-crap is about 1/4" bigger in diameter than VDO, so VDO will fall into the china hole.(BTDT) just keep in mind youll need some sort of spacer or dash re-work...BCNU ~jJ~

I'm talking about putting the VDO mechanism in the Chinese housing and using the Chinese needle so as to keep the same appearance with reliable decent performance. That's why I don't want to switch gauges unless they are VDO Brazil as they fit the same hole as the Chinese ones.

Got a quote from North Hollywood Speedometer; they tell me they are familiar with the problems in these Chinese tachs. What they do is they swap the innards for a VDO unit; price is $160.00 and it has a 1 yr. warranty.

Also got an email from Kirk telling me that they've been having problems with this batch and that the factory in China had to re-do the whole order; he told me to get back to him in a couple of weeks as he's expecting shipment of the new ones. At this point I don't know what I'm going to do; I know that Chinese stuff tends to be that way; when you get something reproduced there the first couple of batches turn out defective but once the bugs are worked out they turn out fine. On the other hand there's a certain degree of peace of mind knowing that your tach is really a VDO in disguise.

"And away it went"...sort of quoting Jackie Gleason...Shipped it today to North Hollywood to get refurbished. Hopefully that will be the definitive solution to this problem...I'll keep my fingers crossed.

For what it's worth, I switched the points to an electronic ignition today and my problems with the tach went away......
Not sure if that was the solution but it's fixed for now.

That's weird because with those tachs I've heard you're supposed to add some electronic components if installing an electronic ignition.

I have electronic ignition and no trouble so far... (knock on wood)

The tach got to NH Speedometers this past Monday and today (Friday) I just got a call from them telling me it's ready. That's a great turnaround time; pleasant surprise. I can't wait to install it....hopefully no more "Chinese Tachometer Blues" (nice title for a song).

Got the thing in last Friday, installed it over the weekend and it works like a charm. I recommend NH Speedometer to anyone with this problem.

My tach and speedo say "VDO" at the bottom. I assume they are VDO gauges, but knowing the Chinese, is it possible that the gauges are the Chinese answer to the genuine VDO gauges (naw, they wouldn't counterfeit those nice gauges, would they)???

No Barry; it sounds like yours are the Brazilian ones.