Tbi swap build thread

[rfmaster]

Originally Posted by 65Guy

im still gathering parts for the swap but i plan on using a vss with my th350. but what if i switch to a 5 speed with no speedo cable provisions what then?

JTR offers differential mounted 40-Tooth Reluctor Ring.



This setup uses a stock vehicle speed sensor (GM part #15547452) which was commonly used on transfer cases of 1989 and newer S-10 truck, AWD Astro Vans, and 1987 and newer full-size 4X4 trucks. The combination of VSS and 40 tooth ring provides 40 pulses per drive shaft rotation signal which would require you to get VSB module to bring it down to 2000 ppm required by TBI ECM. This way you can get around lack of speedometer provision - however I would imagine that these 5 speed tranies would have a built in VSS output which can be coupled into VSB and correct 2000 ppm needed by TBI ECM can be attained. So I would look for a built in VSS and figure out its output characteristics before diving into reluctor ring approach.

As for speedometer - OE gauge will have to be replaced with an electronic unit.

//RF

[65Guy]

one more. i am having a hard time finding a v-8 esc. can i us one off a 4.3 v6?

[rfmaster]

Originally Posted by 65Guy

one more. i am having a hard time finding a v-8 esc. can i us one off a 4.3 v6?

ESC module is a tricky thing. I have not tried 4.3L module on V8, but it should work. Its a buffer - converter between KS and ECM. The output of KS is analog signal and ECM expects digital pulse like signal when knock is detected. The trouble with ESC module is that also provides noise rejection from other internally generated engine noise - lifter noise, piston slap, etc. Different engines and KS sensors have different response frequencies. The early CCC ESC modules were designed with tighter - better rejection filter. Such ESC module is best when used on flat tappet engine - it is less susceptible to engine noise - less false knock readings. Try to find early GM 80's cars or trucks with CCC carb - it will have this module.

//RF

[65Guy]

on cars is it still on the intake like the trucks? Ive tried to find them but it seams that the esc is the first thing that people take at pullapart.

[rfmaster]

Originally Posted by 65Guy

on cars is it still on the intake like the trucks? Ive tried to find them but it seams that the esc is the first thing that people take at pullapart.

Depends on the make & model - firewall on third gens, passenger cars they were mounted on fenders. Any passenger car that was equipped with E4ME, E4MC and E4MED carburetor (especially here in CA) should have ESC module. They are hard to see underneath the jungle of hoses and vacuum lines. Olds/Buick/Pont/Chevy (not sure about cadies) had CCC in the early 80's - God that was great time to be around!!

//RF

[rfmaster]

Originally Posted by rfmaster

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The following is HIGHLY experimental (This has NOT been confirmed to work in our trucks!)

I did a bit of searching and digging - there is a three wire coolant sending unit which combines CTS that is need for ECM and instrument cluster sending unit used in mid 90 cars (1996 Grand Prix for example):

10096181 PCM/Gauge sending unit $14.81 (Wells TU178)
12102748 Connector pigtail (incl. terminals) $17.29
I am going to get a hold of it and run it over temperature to determine its response curves (and its suitability)

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Update
Over the Labor Day weekend I was able to score a sending unit and connector from 90 Olds during my JY trip that produced bunch of other parts. Last week I found a block of scrap aluminum which I drilled and tapped to accept 3/8" NPT sensor.

Test Jig



Next week, time permitting, I'll run some temperature curves against J-type thermocouple bolted near sensor (there are two 4-40 holes) using hot plate for temperatures between +25 and 125C and temperature chamber for -40 to +55C. Should be interesting.

Sensor is OE GM - part number ????
Yellow & black are used for ECM
Green and sensor body are used for instrument cluster gauge.

//RF

[rfmaster]

Well, here are the results.

The OE 10096181 PCM/Gauge sending unit was tested from 22 to about 120C while mounted in AL block filled with antifreeze. J type thermocouple was bolted within 1/4" of the temperature sensor and recorded using laboratory grade thermometer. Both ECM sensor (yellow and black wires) and Instrument cluster (green wire and block ground) were measured concurrently and compared against published specifications for 12146312 CTS.



From the plots it is clear that the ECM output tracks GM published 12146312 spec very well.

The instrument cluster output characteristic is slightly different, but not by much.

However, as it stands, it would appear that 10096181 has a different Temp vs Resistance characteristic when compared to AC-Delco G1852 or Standard TS6 common GM gauge sending units used from mid 60's to late 70's trucks and cars:



The question is then can the cluster gauge bridge circuit be adapted to work with 10096181??? Stay tuned.

//RF

[critict1gc]

ok i cant figure this out i have good power and ground to all my sensors and stuff and when i turn it over my fuel pump turns on and it cranks but no fuel comes out except when i shut it off just a tiny bit skirts out and i got no spark but i have 12v going to the coil

[rfmaster]

Originally Posted by critict1gc

ok i cant figure this out i have good power and ground to all my sensors and stuff and when i turn it over my fuel pump turns on and it cranks but no fuel comes out except when i shut it off just a tiny bit skirts out and i got no spark but i have 12v going to the coil

Check and verify the following:

ECM harness connectors

Pin A6 +12Volts during cranking (and in run position)
Pin B1 +12Volts during cranking (and in run position)
Pin C16 +12Volts during cranking (and in run position)

Fuel injectors are getting power during cranking. 12 volts should be present.

It is very common conversion error to connect ECM and injector wires to a fuse box terminals that go off during cranking.

//RF

[critict1gc]

well what wires do i power up from my computer is it on of the adld wires

[critict1gc]

nope only had power on b1 i dont think i have it powered up properly

[cheepin]

This thread is great!I used it to get my '88 454TBI up and running in my crawler.Well ran it a few times and spun the mains.So I found a '88 350 TBI/700r4 combo with harness.Question is I would like to keep the current harness.What would have to be changed to run the 350?I know I would need to run the 350 throttle body or atleast the injectors.But will the comp run the smaller motor?

[Rifter_Chevy]

Quick question for the very smart people in this thread

Im trying to help out my insane friend who just dropped a 03 silverado cab onto a 79 blazer frame with a 89 TBI engine in it.

Im trying to make the TBI computer work, i dont care about VSS i dont care about check engine lights, data logging, diagnostic ports or ANY emissions related components. I literally just need it to power up and run the injectors.

So to accomplish this is all i need to do power the wire on pins B1 to battery power and A6 to switched power?

[rfmaster]

Originally Posted by Rifter_Chevy

Quick question for the very smart people in this thread

Im trying to help out my insane friend who just dropped a 03 silverado cab onto a 79 blazer frame with a 89 TBI engine in it.

Im trying to make the TBI computer work, i dont care about VSS i dont care about check engine lights, data logging, diagnostic ports or ANY emissions related components. I literally just need it to power up and run the injectors.

So to accomplish this is all i need to do power the wire on pins B1 to battery power and A6 to switched power?

A6 to ignition hot
B1 to battery
C16 to battery
and Ignition Hot to injectors.

Make sure all ground lugs are connected and Ignition Hot +12 volts is present when ignition key is in run and crank position!

//RF

[mcbassin]

Originally Posted by rfmaster

Update
Over the Labor Day weekend I was able to score a sending unit and connector from 90 Olds during my JY trip that produced bunch of other parts. Last week I found a block of scrap aluminum which I drilled and tapped to accept 3/8" NPT sensor.

Test Jig



Next week, time permitting, I'll run some temperature curves against J-type thermocouple bolted near sensor (there are two 4-40 holes) using hot plate for temperatures between +25 and 125C and temperature chamber for -40 to +55C. Should be interesting.

Sensor is OE GM - part number ????
Yellow & black are used for ECM
Green and sensor body are used for instrument cluster gauge.

//RF

Originally Posted by rfmaster

Well, here are the results.

The OE 10096181 PCM/Gauge sending unit was tested from 22 to about 120C while mounted in AL block filled with antifreeze. J type thermocouple was bolted within 1/4" of the temperature sensor and recorded using laboratory grade thermometer. Both ECM sensor (yellow and black wires) and Instrument cluster (green wire and block ground) were measured concurrently and compared against published specifications for 12146312 CTS.



From the plots it is clear that the ECM output tracks GM published 12146312 spec very well.

The instrument cluster output characteristic is slightly different, but not by much.

However, as it stands, it would appear that 10096181 has a different Temp vs Resistance characteristic when compared to AC-Delco G1852 or Standard TS6 common GM gauge sending units used from mid 60's to late 70's trucks and cars:



The question is then can the cluster gauge bridge circuit be adapted to work with 10096181??? Stay tuned.

//RF

Man RF, You have been a busy fellow. That is some cool testing that you have going there! Anytime you need a fixture like that just give me a PM. I have a bunch of scrap laying around. What is the plan with this sensor?

[rfmaster]

Originally Posted by mcbassin

Man RF, You have been a busy fellow. That is some cool testing that you have going there! Anytime you need a fixture like that just give me a PM. I have a bunch of scrap laying around. What is the plan with this sensor?

Thanks for the offer, I'll ping you if and when. Actually, I have being working on universal temperature gauge converter -translator. In other words if you have a characteristic for a temperature sending unit - i.e. Temp vs. resistance and resistance vs. indicated temp for the temperature gauge the two can be matched. This problem is applicable for all classic cars and trucks - gauges were not accurate and original sending units are no longer available.

I have several circuit ideas -that I'll prototype during winter. Also, the design must be simple enough for anyone to use.

//RF

[87Lowrider]

Stumbled on this thread tonight.. considering putting the TBI motor from my '87 SWB into my '57 Stepper... great thread.

[Rifter_Chevy]

Originally Posted by rfmaster

A6 to ignition hot
B1 to battery
C16 to battery
and Ignition Hot to injectors.

Make sure all ground lugs are connected and Ignition Hot +12 volts is present when ignition key is in run and crank position!

//RF

What do you mean by ignition hot to injectors? which pins are the injector pins on the harness?

[rfmaster]

Originally Posted by Rifter_Chevy

What do you mean by ignition hot to injectors? which pins are the injector pins on the harness?

There are two wires that go to each injector. ECM controls injectors via Green & Blue (D14, D16) wire tied to each injector respectively, by 'pulling' these wires to ground. Inside ECM a special switching circuit switches on and off to complete the injector coil circuit. When it is closed the injector coil is energized and injector sprays fuel. When switching circuit is in its off position fuel injector is closed and no fuel is delivered. In electronics this is called a pulled down circuit. The Red & White wires (sometimes both are Red) are connected to IGN +12 volt source so that the injectors coil always has the +12 volts applied (when ignition is on). However, only when ECM commands that fuel must be delivered injector coils are energized. ECM varies duration and frequency of each injector 'spray' event so that the precise amount of fuel can be delivered to meet engine operational requirements.

The two IGN +12 injector wires (RED) are joined together and usually are 14 AWG wire. You'll have to buzz them out with the DVM to see where they in the harness.

//RF

[Rifter_Chevy]

Originally Posted by rfmaster

There are two wires that go to each injector. ECM controls injectors via Green & Blue (D14, D16) wire tied to each injector respectively, by 'pulling' these wires to ground. Inside ECM a special switching circuit switches on and off to complete the injector coil circuit. When it is closed the injector coil is energized and injector sprays fuel. When switching circuit is in its off position fuel injector is closed and no fuel is delivered. In electronics this is called a pulled down circuit. The Red & White wires (sometimes both are Red) are connected to IGN +12 volt source so that the injectors coil always has the +12 volts applied (when ignition is on). However, only when ECM commands that fuel must be delivered injector coils are energized. ECM varies duration and frequency of each injector 'spray' event so that the precise amount of fuel can be delivered to meet engine operational requirements.

The two IGN +12 injector wires (RED) are joined together and usually are 14 AWG wire. You'll have to buzz them out with the DVM to see where they in the harness.

//RF

So i could tie these injector wire into A6 and that would work fine?

[rfmaster]

Originally Posted by Rifter_Chevy

So i could tie these injector wire into A6 and that would work fine?

Yes, but use separate fuse and heavy gauge wire that runs directly to the fuse box! A6 is power for ECM, and is not intended as heavy current circuit.

[Rifter_Chevy]

Originally Posted by rfmaster

Yes, but use separate fuse and heavy gauge wire that runs directly to the fuse box! A6 is power for ECM, and is not intended as heavy current circuit.

oh i will, i have a fair bit of electrical know how just not computer know how. Im not going to overload anything and burn the truck down

[dju91001]

Ok. Im a newbie on this forum. Excuse me for jumping in here. I am doing a tbi swap on my 70 c10. The donor is a 92 caprice L03 305. Iam going to use the entire set up. The ecm is #16136965. Is it true that this unit needs to be flashed in order to work in this swap i am doing? Again excuse my interuption. It just seems like there is more help in this thread on this subject. Thanks

[rfmaster]

Originally Posted by dju91001

Ok. Im a newbie on this forum. Excuse me for jumping in here. I am doing a tbi swap on my 70 c10. The donor is a 92 caprice L03 305. Iam going to use the entire set up. The ecm is #16136965. Is it true that this unit needs to be flashed in order to work in this swap i am doing? Again excuse my interuption. It just seems like there is more help in this thread on this subject. Thanks

It is difficult to say, but first things first. The '6965 uses 80's style UV erasable EPROM. It is not possible to 'Flash' - different type of ROM technology all together. If you are planning to use the complete LO3 setup from 92 Caprice - engine the only minor complication will be VSS. You may want to shed a light on the rest of your drivetrain.

Happy thanksgiving.
//RF

[dju91001]

Originally Posted by rfmaster

It is difficult to say, but first things first. The '6965 uses 80's style UV erasable EPROM. It is not possible to 'Flash' - different type of ROM technology all together. If you are planning to use the complete LO3 setup from 92 Caprice - engine the only minor complication will be VSS. You may want to shed a light on the rest of your drivetrain.

Happy thanksgiving.
//RF

I was under the impression due to an anti theft program or something in the ecm. If not, great! It should work. The rest of the drivetrain is 73-74 blazer with turbo 350. I know about the vss, the park neutral switch, and the detent cable. Going to use the caprice fuel cell with pump unit and lines. The schematics are all similar, so i've found. The cab and bed are 70 c10, just dropped onto a blazer chassis. Thanks