nathanc

hey there guys,

i hate to post a topic that there is a lot out there on and ive done my fair share of research but i just cant get to the bottom of it. Here's the deal...

I've got an 86 toyota pickup with a 22r that i just finally finished rebuilding and got it running again. I put a lot of money in to the build so i figured I'd go out and get a nice set of gauges so im not running with the trusty, "low oil," light. i went out and got a set of glowshift gauges, oil pressure water temp and tach. Spent all day yesterday getting everything hooked up all nice and soldered in. My problem is with the Tach. I start the truck up and the tach registers anywhere from 1,100 to 1,300 rpms when the truck is on high idle which im happy with. i kick it off high idle and it drops to around 1,000 or 900. Thats a little on the highside because i have a timing light with a tach that counts spark off the #1 plug wire and i have my idle set to 600 rpms not too terribly concerned with that part. Where things start to get a little funky is when i tap the gas, and i mean just barely tap it. the tach just jumps straight to 5000 rpms. i dont know what would cause it to jump so high. ive read a lot about a bad ground or power connection causing that. but it works somewhat decently when it idles. i have a pretty long wire run going from the coil to the gauge. the gauge is on the drivers side a piller and the wire runs back along the firewall through the cab to the passenger side, through a hole in the firewall, back along the firewall to the drivers side fender and then to the coil. i have the sensor wire for the tack soldered directly to the wire that had the plug for the sr5 gauge cluster. i cut everything put flux on it and soldered it professionally. i cant imagine that a wire run that long would cause resistance sufficient enough to make it act up like that but im out of ideas here. just for the record i have already checked the back of the gauge to make sure that its set for a 4 cyl and it is. any help clearing this up would be great. it would suck to spend 75 bucks on a tach that gives a reading about as important a screen door bottomed boat. thanks again

wyoming9

iTrader: (1)

Not knowing anything about your aftermarket tach.

Is it one that works on 4 cylinders only ??

If it can be adjusted for 4/6/8 cylinders is it set correct ??

It is for the Toyota Style ignition sometimes it can make a difference been sometime since my racing days so things change.

Getting electrical interference from something ??

Could just be a bad tach in this day and age it happens quite a lot.

Just curious why you want out through the passenger side and did not make a new hole on the drivers side.

nathanc

its a little 2 inch glowshift 7 color series. it has settings for all the way up to 10 cyl engines and i made sure that it was set to 4 before i put it in the truck. Its not specifically made for the toyota coil but i didnt think that was really an issue since all its doing is counting spark. i dont have anything fancy like an MSD box or anything like that just the good old stock coil. Everything that ive read said all you had to do it hook it up to either the negative wire on the coil or the connector for a tach if it has one. i tired wiring it in to both and got the same results. im really out of ideas at this point and the only thing i can really pin it to is maybe the wire run is too long and its just a lot of resistance in the wire. Thats still got me confused as to why it seems to work somewhat decent at an idle.

well, i wasnt really planning on running laps with a wire around my truck to get to something thats a relatively straight shot from the gauge but i already had a hole drilled in that side from where the previous owner ran an amp cable to the battery. i really dont like drilling holes since these are such high dollar collectors trucks haha. i appreciate your time and input, hopefully i can get it all figured or ill be shifting by ear for another 400,000 miles.

wyoming9

iTrader: (1)

What size wire did you use ??

Like 28 gauge ??

Poor connection Someplace??

Then maybe the Tach is just bad out of the box??

Does the manufacture have a customer service number??