GTA91

iTrader: (14)

So we got the '98 LS1 into my '91 GTA and got it running. Most everything is fine except for a few issues... one of which is the tach. At first I just bought a tach signal converter box from baker electronics. The tach would work fine but at about 5k rpms or so it would drop down... sometimes almost to 0 rpms. I then found out we could supposedly tune the tach output from the PCM so we decided to ditch the conversion box. We tried tuning the "high and low pulse dividers" in the PCM but no matter what we set them to we still have the tach cutting out and dropping at higher rpm's. Anyone have any insight here?? It's very weird. Baker electronics said I might need a "signal booster"... I'm wondering if I should just get that and use it along with the tach converter box and see if it all works. I'd rather just not use any gadgets and just tune the PCM to make it work but right now we're not getting too far with that. Any help is greatly appreciated.


Thanks!
-Jeremy

Stu Cool

iTrader: (13)

Do you think this might be related to your alternator issues?

Pat

Red Heartbeat

iTrader: (9)

I worked with BakerElecronix on his very first tachometer module and it works flawlessly in my 2002 LS1 conversion. It doesn't drop anything. I would be looking somewhere else for your issues. Try to borrow an aftermarket tach and see if you have the same issue. My factory tach pegged at 5500 but stayed there while I revved on up to 6500 without issues.

GTA91

iTrader: (14)

I'm going to swap tachs out and see what it does... I'm still think it's something with the baker box... I talked with him and he thinks it might be too. Weird...

shackattack37

iTrader: (4)

i got autometer tach clip wire wire it up as a 4cyl work perfect

GTA91

iTrader: (14)

Did you have to run a tach signal transformer or signal conditioner or anything?? I still can't get mine to work right... still dropping down at 5k rpm's or so. Tuned PCM back to stock tach settings, using the Baker electronics box and works fine until high RPM. I'm wondering if something is wrong with my tach or this signal converter box.... damnit!

GTA91

iTrader: (14)

I ended up using a pullup circuit to get it working at high rpm. 12v switched power plus a 1k ohm resistor, then tied it into my tach signal wire.... works fine now.... just showing 6500-6600 rpms when I'm at my 7000 rev limiter. Oops! Time for a shift light.

waynesia9

can somebody call me and tell me if I'm wiring this wrong 5614 12954 3

1987ssls

Here's the deal , I am new to the interweb stuff, and new to the forum, I have a 1987 Monte SS and put a l33 5.3 and a 4L80e tranny in , all good ! Inner faced all guages ecept for speedo, I have tack signal to guage ot bounces at first crank and settles at an idle and reads right, soon as Rev it even to 2k it don't move according, I rev engine to 4k I might see 2500 on tack, I put the 1k resistor in no luck, then stepped to a 560 no good , then I even wired it in after the factory tack filter , I dont get any change from any thing I do. BTW I haven't gotten into the ecm to change any tack settings , the ecm is a 2002 Silverado 6.0 with 4l80e 2wd. Guesses ! .....Go !