Help me decipher this pleace.. I understand the in and out, but what are the electronics that go downwards in that picture? Shouldn't it all be inline? It IS just some sort of resistor, isn't it?
The schematic is shown correctly. The component in the center and connected to ground is a capacitor. Capacitors pass high frequency (AC) current and block direct current.
One other problem. How do i know which wire is going in and which wire is going out? I don't really have the thing connected at the moment, so there is just the plug sitting near the engine. Thanks
Look at the picture on Rodney Dickman's page, of the replacement tach filter he sells. Now that's a nice, neat package.
The loop terminal is for the ground, I suspect. You connect it to ground (for example, under a screw attached to a clean place on the engine or metal part of the body.
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08:11 PM
Cliff Pennock Administrator
Posts: 11808 From: Zandvoort, The Netherlands Registered: Jan 99
Be aware that that schematics shows the tach-filter for the L4, not the V6. On the V6, it really doesn't do much. I've build a lot of replacement tach-filters myself and they look the same as the original. I still have to post the instructions for that one day.
Yeah, this is for the i4.. What do you mean it doesn't matter on the 6, you don't even need it? Post your instructions man,I can't think of a neat way of packaging it.
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08:44 PM
Apr 6th, 2001
Cliff Pennock Administrator
Posts: 11808 From: Zandvoort, The Netherlands Registered: Jan 99
The schematics for the V6 are slightly different, so are the values for the resistors and the capacitors. Once I've got my digital cam working again, I'll build one and show you how to make a tachfilter that looks alsmost exactly like the original.
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05:06 AM
BRIAN CORNELIUS Member
Posts: 86 From: APPLE VALLEY, USA,MN 55124 Registered: May 99
I was surprised there is a differece in the tach filter for the 4 cyl and the 6cyl engine! When I completed my v-8 swap in my '84 Fiero I recall the radio did have some interferance. I am just completing my second v-8 swap in an '87 and have hooked up the stock '87 Fiero tach filter and was wondering if this is the best approach?
Well, I'm going to try building it today, so i'd appreciate any advice I can get. Did you solder it all to a board, or just the wires together.. I just don't know how I'm going to stick them into a casing?
Well, it seems to work (?) and ended up like Rodney's (sure, I'm sure his is a lot better made, but as logn as I don't short out my car, I'm happy).. My only question is, what if I have it backwards.. I couldn't tell what way was in and out on the plug, so I just took a random guess. I can only assume it would work both ways, but is there a problem with this? Thanks
Seems the tach get's jumpy at 2500 or so.. The guy at the electronics store told me that when converted, the capicitor equals 4700pF... Is that correct.. Could the jumpiness be caused by being backwards? Thanks
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06:01 PM
Cliff Pennock Administrator
Posts: 11808 From: Zandvoort, The Netherlands Registered: Jan 99
Yes, it does make a difference when connected the other way around. But not much. Now if you connect the V6 filter the wrong way, it would make a huge difference.
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06:35 PM
Cliff Pennock Administrator
Posts: 11808 From: Zandvoort, The Netherlands Registered: Jan 99
Oh, and another thing I would like to add is that the original tach-filters for the Fiero are no longer being made. The ones they sell now as a replacement part actually have the wrong resistor and capacitor values.
Originally posted by JohnnyK: Seems the tach get's jumpy at 2500 or so.. The guy at the electronics store told me that when converted, the capicitor equals 4700pF... Is that correct.. Could the jumpiness be caused by being backwards? Thanks
