Tbi swap build thread

[rfmaster]

Pancake

Before I did my conversion I put together a spreadsheet with prices for each component. Spreadsheet is all inclusive - as I've captured used and new parts prices. IMHO $400 for a complete TBI setup including aluminum intake is a nice & convenient package, although the same can be done for little bit less provided that you are willing to search JY's. If this is not the case the following questions must be asked before committing to buy:

1) Intake manifold - What is make and model number of this aluminum intake.

2) ECM 1227747 is listed - what the BCC code.

3) Injector part numbers or color codes (did it come of 305 or 350 CID engine)

4) ESC part number.

5) Dizzy - small hat dizzy - confirm.

6) Also confirm that burban tank can fit in your blazer!! I use rockauto.com search engine that has where used feature - very handy when doing swaps.

You can get BOSCH style relay and socket from any worth while auto parts store. Alternatively, look for 80-90 GM cars at you local JY. MY favorite target (very common in So-Cal) are 4.1-4.5-4.9L front wheel drive caddies as they have a bracket with three relays mounted in a row on a driver side strut tower. When poaching harness make sure to get at least 18 to 24" of wire at the socket. These are 30AMP rated relays, just make sure that wires size is about 10-12AWG. You can wire your winch (provided that it does not exceed 30 AMP current limit)

//RF

[pancake]

I will post the #'s as soon as I get them (before buying them).

The dizzy is the small cap type with external coil type.

I belive all thios, except for the tank, is coming of a 1990 2 wheel drive 5.7 liter truck.

I will also get a VSS when I start ordering the stuff for my TBI conversion.

I wish I had more time to look through the yards but I am out of town working Monday-Friday.

All this, except the fuel tank, is coming off the same truck which should make it a little simpler.

As far as the fuel tank fitting my blazer, It should fit fine. The stock tank is gone (clearance issues) and a fuel cell is mounted where the rear seat was. I can put the fuel tank in the "bed" of the blazer.

[cjracing15]

Check this out.
http://67-72chevytrucks.com/vboard/s...d.php?t=322028

This is out of a 90 subrban witch means all the wires are for a squarebody truck. I used a 90 subrban harness for my set-up and this guy will treat you right. He doesn't sell junk.

[cjracing15]

Originally Posted by pancake

That is a graet deal.

I have a surburban 08/1989 for parts. My friend said it has a blown head gasket. For $300.00 I can have anyuthing off it I want including all the TBI stuff. I will be pulling it tomarrow morning. I can get LOTS of parts off it. I will pull the heads and see how they look. If they are ok I will have the valves done and use them. I will keep you updated and thanks for looking for those deals.

Now THATS a great deal. Make sure you pull all of the tbi stuff harness and all. It will take a little while but I would get every inch of wire that I can inculding the fuse box. Evreything unplugs and comes out intack. So good luck and keep us posted.

[pancake]

So I pulled the TBI stuff from my friends 90 Suburban. I checked the numbers and it is a 350 c.i. set up (ECM 1227747 BCC ASDU). I was not able to get the K.S., it was "stuck". I took the intake to the machine shop Thursday so they could hot tank it and he gave me the 4 shims/spacers I would need to put the intake on my heads (the four ceneter bolts will not line up). I sorted out the wiring and cleaned most of the other parts.


When I was doing the wiring I came up with a few more questions:

On the Oil Preasure sensor there are three wires...The light brown one went to the fuse block...Where does it go? Gauge?

I think I have the rest of the wires figured out except the ADAL connector:

Can you please guide me as to where these wires go?
A-BLK/WHT
B-WHT/BLK
C-DRK BRN
E-ORNG
F-LT BRN/BLK
H-White

Also, I belive it is the neutral switch (one PURPLE/WHT and one Wht wire) has a jumper across the wires at the connector under the dash. What do I do with this?

I can/will post pictures soon.

Thanks again for all the help.

[pancake]

Sorry a few more questions:

C9-PURP/WHT where does it go?
C2-Brown (I do not have a Air Diverter Valve)
D1-LT TAN/BLK ground?

I do not have an A7 wire--where do I hook up the SES light?
A4 GRY goes to the EGR--PNK/BLK bundels and goes to injectors and ESC then loops back to A6(PNK/BLK)
rfmaster in post #108 on this thread you show something coming of A4 (every 1990 5.7 and 7.4L0...I do not have one of these in the harness??

also in post 108 on A6 you have the PNK/BLK wire going to hot in start and run..and ECM 1 fuse. what is the fuse rating? (10,20,30 amp?) what should the rest of the fuse ratings going to the ECM (B1,A4)

Where should I start looking for a wire that is hot in start and run?

[cjracing15]

C-9 Goes to the small terminal on the starter. ( tells the computer when the starter is engaged)

C-2 You can just disregard this wire.
D-1 Is a system ground. I just ran a main ground for the computer system and grounded it at the back of the head. (Pass. side)

You are right there is not an A-7 wire but there is an A-5 and this is your ses light. It is a ground the the cpu turns on when it needs to. I just used my choke light and put a switched 12 volts to one side and then wired in A-5 to the other side. works great.

A-6 as you said is pk/blk. It ties into sevral places in the harnes to give switched 12 volts where needed.

As for the fuse rating I think stock is 10 amp.

For b-1 I used a inline 20 amp fuse.

as for A-4 it is just a ground from the cpu to turn on the egr relay. so a fuse is not needed.

[cjracing15]

Originally Posted by cjracing15

Ok here are all the pin outs and the color of the wires. My computer is the standard #1227747

A1- grn/wht- this wire is used to power the fuel pump-relay.
A2- no wire
A3- no wire
A4- gry- to egr-relay. This is a ground for the ECM to control the EGR relay.
A5- brn/wht- service soon light. This is a ground to turn on the light.
A6- pink/blk- switched 12v from the ignition relay.
A7- no wire
A8- ornange aldl serial data wire pin-e
A9- wht/blk-aldl pin B When jumpered to ground will set the computer to diagnostic mode.
A10- brn- VSS speed sensor signal to the computer, (This wire I will wire this to on side of a after market VSS sensor and the other wire on the sensor goes to ground).
A11- blk- MAP sensor ground.
A12- blk/wht- System ground. This wire is tied to other grounds in the harness and goes to engine ground.

B1- orn- 12v batt power ( I looked and traced down this wire on my 87 cab harness and this is fuesed I think it was a 15). I will probably use a inline fuse.
B2- tan/wht- Fuel pump signal from the relay. This one ties into several places, the fuel pump, the relay, and the ecm. When the relay is on it sends 12 volts to trun on the fuel pump.
B3- blk/red- Distributor plug
B4- no wire
B5- purple/wht- Distributor plug
B6- no wire
B7- blk- ESC signal This is the knock sensor signal to the computer.
B8- dk grn- AC signal. This tells the ECM that the AC is turned on. I am going to tie this into the ac clutch wire.
B9- no wire
B10-orange/blk- park neutral switch wire. some people say this is optional but I do not think it is because it gives a signal to the computer to give the engine a slight bump in rpm.(if you don't need it why did they put it there?)
B11- no wire
B12- no wire

C1- no wire
C2- brn- wire is not needed
C3-grn/blk- Idle air control
C4-grn/wht- Idle air control
C5-blue/wht- Idle air control
C6-blue/blk- Idle air control C3-C6 all go to the Idle air control valve plug on the TBI it's self.
C7- no wire
C8- no wire
C9- purple/wht-Starter crank signal wire. Goes to the small terminal of the starter.
C10- yel- Temp sender
C11- lt grn- Map sensor
C12- no wire
C13- dk blu- throtle position sensor
C14- gry- signal to map and TPS. ( you will see it tied together in the harness)
C15- on wire
C16- orange- This wire is tied with B1 so it is a 12volt wire

D1- brn/wht- system ground goes to the engine.
D2- blk- tied to the wires for the engine ground.
D3- no wire
D4- wht- distrbutor plug
D5- tan/blk- distrbutor bypass. This is the wire that you disconnect to set your timing.
D6- Tan- O2 sensor ground to engine.
D7- purple- plugs in to the o2 sensor
D8- D13 no wire
D14- grn- Injector plug plugs into the top of injector
D15- no wire
D16- blue- Injector plug plugs into the other injector

This might help also if you don't have it. It is on the first page of this thread. Again good luck.

[rfmaster]

Pancake

Looks like you are digging into retrofit - full speed ahead

For P/N switch functionality you'll have to wire a small, simple circuit which requires some wire (12 AWG purple and 16AWG, 1/4" crimp connectors (female and male), BOSCH 30 amp relay, and silicon diode 1N4001 - Radio Shack.

Questions???

//RF

[pancake]

Ok...almost ready to put the tbi on my Blazer.....but have another question. I understand the wiring for P/N switch but do I NEED this for a manual tranny?

again, thanks for all the info and advice.

[rfmaster]

pancake

To get things going it is not required, but having a neutral position sense switch will improve driveability (i.e. ECM alters idle and timing somewhat (depending on ECM, other parameters as well - EGR operation, AIR) between neutral position and being in gear.

Leave B10 (orange-black) unconnected for now (this way ECM will see that truck is always in gear).

//RF

[pancake]

Sorry if this is a repeat post, The other one did not look like it was posted.

Almost ready to install but had a few more questions:

My Oil Pressure Switch has three wires coming off it: orng, gry, and light tan. I know where the orng and gry wires go but where does the light tan wire go?

To install Dizzy do I need to find TDC on #1 and install dizzy so rotor points at #1 plug wire?

What should I start with for timming for a TBI 5.7L?

I need to disconnect a wire to set timming? D5 lt brn/blk wire?

Any advice on timming or insatlling the Dizzy would be great.

Thanks again for all the help and I hope people are getting some usefull information from this thread!

[pancake]

Sorry forgot about the ADAL connector wire questions:


A blk/wht is a ground?
B to A9?
C brn wire is for the Air Divirter? What should I do with it?
E to A8?
F Lt brn/Blk....Where does it go?
H whith wire...Where does it go..looks like it attaches to a few more white wires.

Thanks again

[rfmaster]

Originally Posted by pancake

Sorry if this is a repeat post, The other one did not look like it was posted.

Almost ready to install but had a few more questions:

My Oil Pressure Switch has three wires coming off it: orng, gry, and light tan. I know where the orng and gry wires go but where does the light tan wire go?

Orange is battery side of FP supply circuit, gray is the fuel pump (FP) side of the circuit. Tan wire goes to oil pressure gauge (depending on switch part number it can be gauge or oil pressure light)

Originally Posted by pancake

To install Dizzy do I need to find TDC on #1 and install dizzy so rotor points at #1 plug wire?

Yes, you need to find #1 Cylinder TDC and corresponding dizzy post.

Originally Posted by pancake

What should I start with for timming for a TBI 5.7L?

0 TDC with EST connector open is a standard for truck TBI.

Originally Posted by pancake

I need to disconnect a wire to set timming? D5 lt brn/blk wire?

You should have a single wire weather pack connector - usually it is light brown with white or black stripe. Try to get your engine going first, then set the timing once it warms up. 0 TDC is the number. With EST connector open ECM will set code 42 - this is perfectly normal. Clear it by disconnecting battery after shutting engine.

Originally Posted by pancake

Any advice on timming or insatlling the Dizzy would be great.

Thanks again for all the help and I hope people are getting some usefull information from this thread!

Before taking original dizzy out remove hat and turn engine by hand until balancer reads 0 TDC and mark and rotor points toward #1 on dizzy. Mark that location before removing dizzy from intake. As you pull dizzy out the rotor will turn counter clockwise. Mark the final position as well. The idea here is to pre-align TBI dizzy so it just drops in place of HEI. Otherwise, turn engine to the 0 TDC and with a help of 12" BFS turn oil shaft as shown in the figure below. The key is to have oil pump shaft slot to line up with #5 Intake rocker (approximately). Turn TBI dizzy counter clockwise so as it drops it will turn clockwise and engage oil pump shaft. Whoa la!

[rfmaster]

Originally Posted by pancake

Sorry forgot about the ADAL connector wire questions:


A blk/wht is a ground?
B to A9?
C brn wire is for the Air Divirter? What should I do with it?
E to A8?
F Lt brn/Blk....Where does it go?
H whith wire...Where does it go..looks like it attaches to a few more white wires.

Thanks again

Good question

ALDL Pin - Function - wire color - ECM pin
A - ECM ground - black/white - A12
B - ECM Diagnostic request - white/black - A9
C - Air diverter - brown - C2 (not used in your application)
E - 160 baud data ECM - orange - A8
F - Shift light or TCC - tan/black - A7 (not used in your application)
H - Antilock computer data - not used in your application

//RF

[pancake]

Hace some pictures of the TBI setup before install:



I will get more pictures up as soon as I can figure out how to make the files smaller

Here are some #'s off the TBI set up:

Intake # 14102182

TBI Body 17090061 2139 KCD

Injector #'s GM5235206 and the small # is 7259GM* on one and 7279GM* on the other..Is this a problem?

EGR #21698 or 2169B (not sure if it is a B or an 8)

ESC #GM 16052401 9161

Number on the Bottom of the Dizzy 1103749 9H 4

[pancake]

Some more pictures:


Picture:

#1 wiring harness after sorting out the wires. I need to soilder the ends back that were cut to seprate the wires ( common ground, and orange wire)

#2 Everything laid out on my garage floor.

#3 Sensors, EGR, ESC< Fuel pump relay ( will get new 4 wire 02 sensor and a VSS)

#4 some shims the machine shop gave me to mate the new intake with the old heads.

#5 The intake fresh from the hot tank.

[rfmaster]

Pancake

GM5235206 injector is rated 61 lb/hr at 13 PSI and was a standard issue on 350 Trucks and should have orange - black paint (some of it is still there). 7579 and 7279 is a production date code. Makes no difference to have different date codes.

TB 17090061 was used on 1987-1990 350 TBI trucks. Nothing special, but make sure that throttle shaft moves nicely and there is no slop due to worn shaft holes.

ESC 16052401 was used in many different EFI and CCC applications. When used in combination with 10456288 KS it should work just fine with your 350

1227747 ECM with ASDU code - very commonly used in conversion from carb to TBI. Depending on heads and compression timing may need to be augmented.

Intake manifold - just make sure that you can bolt it down.

//RF

[brontotx]

Great thread... wish I'd found it a year ago when I did a TBI swap into my C20, which is a "mutt" made up of my restored, but wrecked, '82 Camper Special (never lend trucks to girlfriends!) and an '85 with a straight body and frame, but bad engine, shot front suspension, brakes, and rear axle, butchered wiring harness, etc., etc. After getting the mutt running in late '05, I had the usual drive/tune-ability issues with the q-jet and got a full '87 TBI set-up off of e-bay. It took me a few months to sort through it all in the driveway (yup - I'm a bona fide shade-treer, subject to working in daylight when the weather is good). I have it running (and it runs very well if I do say so myself) - I'll mention some of my "insights" (more like problems I dealt with) later.

I ended up using the dash and rebuilt steering column from the '82 due to the '85's butchered wiring harness, shot steering column, and butchered metal dash sub frame (think hacksaws and ball peen hammers). While I installed a new stalk switch for the turn signals and cruise control, I never hooked up the cruise as I mainly use my truck for hauling stuff around town. I am about to go on a longer trip and want to get the cruise operational, so my questions are:

1) What do y'all recommend for the cruise: using the '82 or getting the parts for the later '85 or '87? I think the '82 would be cheapest since I have all the parts (I have some of the '85 parts too), but am concerned about the speedo cable wind-up I see, which is mostly at low speeds, so may not be an issue.

2) If I go the later model route, can I use the VSS signal from the JTR adapter I installed at the transmission end or do I need to get a later instrument panel too? My guess is no as I presume the later speedo-based VSS provided vehicle speed to both the cruise and ECM, but wanted to confirm with y'all.

3) Any other considerations I need to be aware of to help my decision and/or on getting this to work?

Some of my "insights" on swapping a TBI into an older vehicle:

1) Get manuals (or at least wiring diagrams) for both vehicles.

2) A factory TBI manifold requires modification if older heads are used (mine are mid-70's 333882's). I carefully used a disk grinder on the drivers side of the manifold to alter the angle for the bolts and made angled spacers for the passenger side.

3) If you want to use the TBI ECM's electronic lock-up for the 700R4 transmission, get a 700R4 from a later year. My '82 700R4 was not compatible with the ECM and, since my '82 was showing signs of wear (some slippage and lots of silver in the fluid), I got a used '87 700R4 that is compatible and has been working great.

3) Using the original 5/16" return line can result in excessive back pressure, which keeps the fuel pressure too high and makes the vehicle run real rich. FWIW, I have dual tanks and decided to use a Carter in-line fuel pump I found on Summit Racing "designed for TBI swaps into carburetor applications". I installed a fuel pressure gauge at the regulator and the Carter was running at 22 psi, no matter what regulator spring I installed, or how many coils I cut off the springs. I ended up disconnecting the 5/16" return line in sections to see where the back pressure was and found that even short sections had measurable back pressure compared to 3/8" line. After replacing all the return lines with 3/8, except for a short section of 5/16 for the tank selector solenoid, my pressure was down to 17-18 psi... close, but still running rich with a stock ECM calibration. I then found a vacuum adjusted fuel pressure regulator on e-bay and installed that... 12 psi at idle and up to 18 when WOT.

4) Even after sorting out the fuel pressure, I was still running a little rich and attributed it to the stock ECM calibration combined with the older heads and RV (high torque) cam I have in my engine. Researching my options, I ended up buying an EBL ECM, which replaces the PROM with flash memory and comes with "optimization" software. It wasn't the cheapest route, but after data logging and re-flashing my ECM a few times, my truck is running unbelievably well. Fuel mileage is up some 20-25% too (yippee!).

Anyway, sorry for the longish first post, but I wanted to share some of the problems I had and my solutions. And I would appreciate any insight anyone might have on getting my cruise functioning.

Mark

[rfmaster]

Hey BrontoTX

Welcome to the board. IMHO, Mutts make best friends for life.

My '75 is as simple as it gets - no cruise control. I am not in a position to make comments regarding cruise controls.

VSS input - this is a tricky one, but you can probably adapt later DRAC unit to drive both ECM VSS input (2000ppm) and cruise control computer. The critical part is re-programming DRAC to match your rear end gear ratio, tire size and spedo gear ratios. In the past I found a page were this was documented, but it escapes my recollection at this time. Try Googling. Otherwise, get JTR 2000ppm VCC unit and DRAC in series with each other.

I am not a column expert - try a focused post instead.

TBI comments.
1) Definite yes, I pick-up B-Body FSM - it was cheap and covered ECM that I was using for my conversion.

2) I used pre -87 specific TBI intake, Holley 300-49. (I did not care for grinding) Alternative is to get Q-jet to TBI adapter plate and keep original manifold.

3) There are about dozen variation in 700R4 internal wiring. Two years later I have not hooked up my TCC function in my 700R4. Yes, I know I am bad.

3a) - Avoided back pressure problem by using 3/8" line everywhere. I also use Carter P5000 inline pump - works great. In addition I use a surge tank and a lift pump - both of my tanks are fully selectable and functional.

4) I run EBL conversion with my ECM - the best thing for tuning. I still have some tune work to do ( I have false knock due resonating exhaust system). Overall gas millage went from HWY 13MPG to about 17MPG (700R4). Original HWY (TH-350) was a dismal 10-11 MPG (I have 4.11 gears and 14 bolt rear)

//RF

[FRENCHBLUE72]

This is a great thread guys I am so glad that it was started however I wish I would have stumbled onto it earlier in my conversion process as I am almost done now... So I am sure I will have questions when I finally get ready to fire this baby up...

[brontotx]

I have looked at both the '82 and '87 factory service manuals and have come to conclusion that the cruise control and ECM are simply not connected in this era of trucks. There is the obvious exception of the VSS signal being used for by both the ECM and cruise in post-'87 trucks, which I determined through additional web research to both use the 2000 ppm signal. So, IF I went with the later cruise control (which I have decided not to do - see below), the VSS signal I am getting from my JTR 2PRS should feed both the cruise and ECM, just like they do when the VSS signal comes from the speedometer on post-'87 trucks (and cars).

Basically, my '82 cruise set-up uses a transducer and vacuum modulator mounted on top of the driver's side inner fender to understand and manage the speed when cruise is on. In essence, the transducer is a VSS-like signal, but internal to the cruise control. Since I have all but one of the '82 parts (I'm missing the throttle rod), I have decided to simply try and get this system functioning as the TBI and ECM really don't "know" (or care from what I can determine) if the cruise is engaged. Once I get the throttle rod and have a chance to test and diagnose the '82 cruise system, I'll report back how it works (or not) with the '87 TBI set-up - wish me luck.

RF - you are correct about there being about a dozen variations of the 700R4 TCC lock-up circuit. Since I had purchased an '87 TBI set-up from the e-bay seller in Brenham, TX, and since Houston (where I live) is only about 80 miles from Brenham, I contacted him and purchased the used '87 700R4 from the same donor vehicle (an '87 1/2-ton Suburban) as the TBI was pulled from. The used tranny was in good shape (clear, non-burnt fluid) and has been performing well for some 5,000 miles now. Given the heavier duty nature and use of my C20, I also installed an aftermarket auxiliary transmission cooler and an outboard transmission filter mount/kit that included a temperature gauge, which I use to keep an eye on when towing.

Also, my Carter P5000 pump works great too, although my first one was replaced under warranty by Summit since the first pump occasionally "locked up" and I had to "jump start" it by bypassing the relay using 12V+ direct from the battery to the pump. Given the problems with the first pump, I also purchased a spare since the Carter pump is the only part in my TBI conversion that is not available at my local auto parts store.

I also have a weird problem with the pump running for a few seconds after shutdown. I replaced the fuel pump relay and this problem occurs with both the pre-EBL ECM and the EBL ECM, but the pump still runs on, so my guess is that the ECM signal "decays" instead of shutting off instantly, keeping the relay engaged.

I did not install a surge tank or lift pump and both my tanks are selectable and functioning like yours. While I am happy with my set-up, perhaps you could elaborate to me and others on why you felt these were required?

Again, thanks to all for this great thread.

Mark

[FRENCHBLUE72]

Can someone tell me really quick what color the wires should be on the starter pink or red?

[brontotx]

Originally Posted by FRENCHBLUE72

Can someone tell me really quick what color the wires should be on the starter pink or red?

It is pink on my '82 wiring harness, but may be different for other years.

[FRENCHBLUE72]

Looks like I wired it up correct then... sweeeeet