aljohnsonii

I have 89 tbi with A t5 with a manual speedo I'm lost I was told that a vss controls engine rpm by reading speed and is attached to the back of the speedo on manual transmission I'm putting a 91 t5 speed density and was told that I need a vss at the trans in order to tell ECM how fast the car is going to control rpm I'm trying to find out what I need to get the car running tpi and t5 speed density in my car with manual speedo thanks

utilityguy2

iTrader: (1)

I believe you can pickup the VSS signal at the yellow buffer box located at the instrument cluster and route it to the VSS input of the ECM.

aljohnsonii

I was told to buy a adapter to put in between my trans and cable and hook that to pigtail off wire harness but i have no clue what chip and computer goes to what

utilityguy2

iTrader: (1)

you need a 1227165 ECM with the proper TPI Memcal. Also the proper wire harness. As I said you should already have the VSS signal you need at the Buffer but you could get the adapter but why?

utilityguy2

iTrader: (1)

you also need a high pressure fuel pump to replace the low pressure one you have.

aljohnsonii

I have the tpi in car with hi volume pump already just seems easier to go with adapter than and pluging it in to factory harness than fighting the buffer and ECM

aljohnsonii

I had the maf tpi harness on car from 89 and then car wouldnt drive down the road idle fine but wasn't reading the buffer on speedo right

vetteoz

iTrader: (13)

Doesn't the TBI have the same 2000 pulse VSS as the MAF TPI
while the 90-92 ' 730 speed density ECM requires a 4000 pulse signal

On a '730 ECM; the VSS goes direct to the ECM and it has a output to the speedo

"The MAF setups with an electric speedometer had a VSS buffer box mounted behind the dash.
The VSS signal runs to the buffer, and the ECM grabs the VSS signal from the buffer box".

aljohnsonii

That's what I thought to but when I installed the tpi and done away with the throttle body the car ran fine at idle but when I got up to speed it would starve for gas and everything I've search was that I was suppose to have the vss sensor at trans for that computer and Im not fond of maf so I ditched that harness and going with speed density and just but the adapter plate I just don't know what ECM or prom to get and what ECM pulse because I can get both 2000 pulse a min or 4000 pulse a min

utilityguy2

iTrader: (1)

I'm getting confused. What ECM are you using? If you changed to the 1227730 then yes, you need a 4000 pulse per mile VSS. You actually do have a 4000 pulse now going to the speedometer which was converted at the buffer from the 2000 pulse VSS. In the 730 ECM there is an input and output and it could be scaled there to get what you want but you may be correct that it is easier to get a 4000 pulse VSS wired to the ECM and the use the 2000 pulse output to the buffer input. Bottom line, 1227165 MAF uses 2000 ppm and the 1227730 uses 4000 ppm but can output 2000 for whatever you want like the cruise control or run to buffer box to run speedometer.

aljohnsonii

So all depends on what ECM I have but my problem is I have 3 ECM and proms I know for a fact that one is for 91 speed density tpi auto one for 89 throttle body t5 and one for a 85 fire bird tpi with auto but I don't know where to find the numbers on ECM or the numbers on the ECM prom to determine what will work on my speed density harness with a t5 I have to find out in order to buy my ECM prom and adapter to hook my vss to my manual speedo

vetteoz

iTrader: (13)

Should be a white label on the ECM case.
91 MAP ECM SERV # 1227730 and has 3 plugs could also be 16196344 or 16198262
85 TPI ECM SERV # 1226870 and has 2 plugs
TBI should be SERV # 1228746 and has 2 plugs

ECM's are the same for a engine type
only the tune on the prom inside determines what setup it is for ;305 or 350 ; auto or manual

vetteoz

iTrader: (13)

Only the # 1227730 ECM will work for SD TPI

If you have cable drive speedo and need the VSS adapter see
http://www.ebay.com/itm/90-92-TPI-Re...item5648a85fd9


https://www.thirdgen.org/tbitotpi

aljohnsonii

How do I know what ECM prom will work for t5 I have a computer for a 91 auto tpi but the prom is go a auto

utilityguy2

iTrader: (1)

There never was a 350 tpi with a manual transmission but there was a 305 manual. Either way, the 91 SD prom needs to be re-programmed for a manual transmission. See the listing in 3rd gen's for sale forum for a Memcal to run your car. If you list the 3 or 4 digit BCC of each prom (silver label on prom or blue cover) I or someone else can tell you what they are originally for.

aljohnsonii

Mine I have say

Delco
ARAD
4868

What does it need to read in order tO work with the tpi speed density t5

ninetyone

iTrader: (2)

90' and up tpi uses no buffer, ecm should gets its signal straight from vss and then ecm sends signal to speedo.

ninetyone

iTrader: (2)

Just use a 91' 5 speed prom, with the 7730 tpi ecm (1990-92)

ninetyone

iTrader: (2)

You would use the vss for a 1990-92 305
Speed density 5 speed. Then IIRC eliminate the buffer box and connect the two brown wires at the buffer box together. Then yould need to just switch two pins at the c207 connector(a clear,underdash bulkhead connector near the ecm)
Connecting pin D (gry) to pin K (empty)together and the speedo should now work

ninetyone

iTrader: (2)

Ecm's are the same from 90-92, regardless of 350,305, manual or auto. Its just the prom (chip) thats different.

aljohnsonii

My speedo works fine its manual cable driven straight from trans I have the computer Im trying to get the right prom ( chip ) or number on the prom so that I can find one

vetteoz

iTrader: (13)

Seems to be a echo in here

vetteoz

iTrader: (13)

ARAD is for a 350 auto BUT it is for the earlier MAF '165 ECM.
Won't work in your MAP ECM
Sell it to someone doing a MAF 305 TO 350 swap

utilityguy2

iTrader: (1)

First of all, aljohnsonii has never said which motor he is putting the SD TPI on. If he needs information he should really give all of the facts, they are important in helping provide answers. Second, It does not help to have people jump in without reading the first part of the postings. It just confuses everyone. I believe Aljohnsonii simply wanted to know what was involved in putting a 91 SD tpi setup on his 89 Map 305. I think we addressed everything quite a ways up. If you have anymore questions, please give a little more detail of what you have and what you want and we can help.

aljohnsonii

Sorry bout that utility guy been talking to a bunch of people about I have a 89 305 ho with t5 manual speed ometer that goes from trans to back of speedo I put a harness from 89 maf and it would drive it would idle right and I didn't care for the maf so I'm going to map instead but I don't have the emc prom I currently have a tpi 305 in it with t5 Bd ordered a 91 harness i have a 91 computer with a 350 tpi auto prom but im looking for a prom for 305 t5

utilityguy2

iTrader: (1)

PM sent

aljohnsonii

Mostly I need to know what the number is on the prom for the 1990-1991 tpi map 305 manual transmission so that I can look and get right one

utilityguy2

iTrader: (1)

AXXD is the latest but there are other broadcast codes that will work. Even if you get one, the car won't start because VATS needs to be disabled in the programming. I sent you a PM with the info you need.

aljohnsonii

Why would the vats not work

utilityguy2

iTrader: (1)

some 89s had VATS (security) some not. If yours originally had VATS and it was correctly hooked to the ECM it would probably be OK. All SD Memcals had VATS enabled as stock so in most cases of modifications it would need to be disabled by programming or mechanically bypassing it.

DBRjeep350TPI

On a 7730 ECU the B10 pin out gets a High 4000 pulse from the VSS from that single wire. but the other B9 pin out is a 2000 pulse, now that wire is not hooked up at all unless you are running cruise control or the speedometer...
i am really just looking to get a 4000 pulse to my ECU, so all in all i really only need the single wire from the VSS of 4000 to the ECU.

utilityguy2

iTrader: (1)

Actually you need two wires B9 and B10, high and low, yellow and purple to the ECM. C1 is the 2000 output to the Cruise control.

DBRjeep350TPI

So B10 is requiring 4000 high pulse and the B9 is requiring a 2000 low pulse to the ECU?

utilityguy2

iTrader: (1)

No. both are 4000 from the VSS. the high (B10) is voltage and in this case the low (B9) is ground. Both of the two wires from the VSS need to be connected to the ECM. There is no 2000 ppm at the VSS. That is made in the ECM from the 4000 pulse signal and is output on C1 if needed.

utilityguy2

iTrader: (1)

The VSS signal is a AC voltage sine-wave. So like all AC current it alternates. That's why you need two wires. Voltage and ground alternating. The VSS on these GM 7730 cars is a two pulse two wire Hall effect sensor. They produce 4000 pulses per mile AC sine-wave.

DBRjeep350TPI

I think I figured it out... I am using a Dakota Digital SGI-5C converter with the configuration for the Hall Effect 16K sensor and running the pulse to the speedo and a 4000 pulse to the output to the ECU. Well I ran the VSS low to the 2000 pulse output on the SGI-5C unit and should have ran it to the sensor ground output on the box. For some reason I was think the B9 pin-out needed 2000 pulse and the B10 pin-out needed 4000, but now going to try the B9 to the sensor ground and the B10 to a 4000 output signal.

utilityguy2

iTrader: (1)

You can do it that way but remember to set the SG-5 output to 4000AC not OC.

A better way is to run the two wire 4000 VSS pulse directly to the ECM and run the 4000 pulse output at B11 to the SG-5 4000 pulse input.

I'm guessing you need the pulse for the speedometer thus the reason for a SG-5. Most aftermarket speedometers can take any number of pulse inputs and some even have outputs. and You would not need the SG-5.

Don't mix up inputs and outputs up or you can damage the ECM or SG-5.

DBRjeep350TPI

I wish i could run the 2-wire VSS wire directly to the ECM, but I dont have a VSS sensor that provides a 4000 pulse. only the Hall Effect 16K pulse, thus the reason for the SGI-5C unit to create that 4000 pulse. My Speedometer is a nice VDO unit that has the processor to manually adjust the PPM up and down. But i do not see in the instructions anywhere of a output 4000 pulse to the ECM, if it did I would ditch the SGI-5C unit.

I only see one input signal to the SGI-5C unit and i have the 16K Hall Sensor plug in there. and I am using the OUT3 that is "4000ppm AC output" to the ECM.

utilityguy2

iTrader: (1)

Now I see why! Yes then you are doing it correctly. input the 16k to SG-5 and out three to the ecm. Do you have any scan equipment or laptop with Tunerpro so you can see the Signal is working to supply the mph in the ECM? That would be nice to know for sure.

DBRjeep350TPI

I don’t have any of that equipment... all I have is an OBDII scanner and a check engine light. I knew something was wrong when the check engine light kept coming on and going off. Hopefully it is cause I have the B9 Low VSS pin-out plugged into the 2000ppm output and not the sensor ground.

If that is the case and it fixes the check engine light coming off and on... having it the way I did… Would that have affected the system to go into highway mode or performance of the engine having the 2000ppm incorrectly plugged in like that?

utilityguy2

iTrader: (1)

if you don't have a 4000 pulse signal to the ECM it will not go into highway mode plus a lot of other things won't work correctly.

Running it with 2000 pulse into the B9 input may or may not have caused any damage but VSS certainly would not have worked which could definitely give you SES light.

DBRjeep350TPI

well i will get that B9 input switched over this weekend and let you and others know. It seems to run fine and power. just the SES light pops on and off here and there.
you say damage. To the ECM or SGI-5C unit. I have a few extra ECMs i can throw at it if i suspect its not working. what are the " lot of other things won't work correctly" are? so i can check.