chrisp3

Is there anything that will convert the tach signal (the 4 pulse) so the factory tach will understand it? working with a 98pcm/69 camaro

I have seen a signal generator for the vss to convert to cable (in order to use the factory speedometer) but haven't come across anything that will convert the LS1 signal for the tach.

Anyone?

ChrisP

G-Body

iTrader: (4)

HP Tuners or EFI Live7. You don`t need any external box or convertor. Just have whoever is reprogramming your PCM set it up. BTW the factory LS1 tach signal is a 2 pulse per rev and the tach for your camaro is looking for 4 pulses per rev not 8.

You could also get a convertor box from dakota digital, or baker electronics(check e-bay), but I think it is much easier to just change the parameter in the PCM.

the_merv

iTrader: (88)

It is a thing that can be tuned. I am looking at the same thing when I do my swap.

Rodder

iTrader: (2)

Just fixed this on mine this afternoon--much easier to fix in HPTuners than pulling the gauge back out. I'm using a 99 PCM, not sure if the 98 has the same option--apparently it's OS dependent. Stock, both of the "tach resolution" values are "6". Change both of them to "3" for an 8-cyl tach.

chrisp3

G-BODY- Thanks for the correction on the pulses. Looks like thats the way I'll go when I hand my pcm over to MTI.

Rodder- When you wrote, "Stock, both of the "tach resolution" values are "6". Change both of them to "3" for an 8-cyl tach" is that the same thing as going from 2 pulses to 4 pulses?, or does your statement pertain to HPTuners only.

Thanks for the help

ChrisP

G-Body

iTrader: (4)

That is the same thing, when you are in EFI Live7 or HP Tuners and go to change the tach output it does not have the # of pulses listed, it has an equation and you can change the number of pulses by changing the variable "n". Its hard to explain, but easy to understand once you see it. I believe that putting in 3 for the n value with either software will make the output a 4 pulse/rev V8 tach signal, but don`t quote me on the 3#, I don`t have any tuning software I was just standing there watching jesse while he tuned my computer with EFI Live7.

daniel6718

iTrader: (36)

ok im just wondering i had a local shop tune my car and i believe they said they were using hptuners, but they couldent find what they needed to change, since theyve never done it before, can yall give me a direction to tell them?

the_merv

iTrader: (88)

Mine was done with EFI Live..
Daniel- you said that all the people around you had HP Tuners..see if it's not LS1 Edit or something like that..

Rodder

iTrader: (2)

Engine->General->Tach Output

Tach Output Resolutions - High Change to 3 for 8cyl tach

Tach Output Resolutions - Low Change to 3 for 8cyl tach

daniel6718

iTrader: (36)

im doing this in a 94 so the number will prolly be differant but thats what i needed to know where to tell them to look, i think im going to buy hp tuners, this is bs, im tireg of shelling out money for tunes

the_merv

iTrader: (88)

That's the same thing in EFI Live..

Rodder

iTrader: (2)

what I posted was for LS1's, don't know anything about LT1.

the_merv

iTrader: (88)

That's what I was saying... that is the Pulse Rate we converted my Tach to to in EFI Live.

daniel6718

iTrader: (36)

heres s question for you experts, can you change it with ls1edit? if so how?

daniel6718

iTrader: (36)

anyone know about ls1edit?

89 formula350

iTrader: (8)

still no reply on this? I plan to buy an editing program and this will be one of the things I need it to do

hosspowerinc

iTrader: (22)

Yeah I need to know this too. I just got LS1edit but havent received it yet. It better be able to change the signal

67rsss

iTrader: (4)

If you don't watn to mess with the computer, the Dakota Digital box works great.

Rodder

iTrader: (2)

You can change it with HP Tuners or EFI Live, as I and other people have already said. I don't know anyone using software other than HP Tuners or EFI Live. You mihgt have better luck asking in the Tuning forum here, but I expect they'll just rag you for buying anything other than HP Tuners or EFI Live .

eagleuh1

Can hp tuners change the setting in a 2005 Suburban 5.3 pcm to allow a S10 V6 tach to work with the pcm output?