Tbi swap build thread

[rfmaster]

Basic ignition and power



//RF

[408cuda]

Just a quick update. It lives! Had it running 3 or 4 times today. Sounds decent but did trip the SES light for the o2 sensor which was no surprise as it's jb welded into ~2' of ex pipe and the other side is open header. This was just to see if would even run. Lots of odds and ends to do now but we're on our way. Pretty uneventful test fire overall. We hooked the donor tank up under it and once it had fuel psi to the TB she took right off.

Checked the alt and only showed about 12.5v, need to look into that still.

rf, the diagrams are amazing. The ignition one will really be a great help to those thinking of doing this. I plan to study the headlights and will put to use when we get to that. Thanks again!

Hope I didn't steal your thread cj, but another tbi swap running and you guys were a big help. More questions to follow I'm sure.

[rfmaster]

Originally Posted by 408cuda

Just a quick update. It lives! Had it running 3 or 4 times today. Sounds decent but did trip the SES light for the o2 sensor which was no surprise as it's jb welded into ~2' of ex pipe and the other side is open header. This was just to see if would even run. Lots of odds and ends to do now but we're on our way. Pretty uneventful test fire overall. We hooked the donor tank up under it and once it had fuel psi to the TB she took right off.

Checked the alt and only showed about 12.5v, need to look into that still.

rf, the diagrams are amazing. The ignition one will really be a great help to those thinking of doing this. I plan to study the headlights and will put to use when we get to that. Thanks again!

Hope I didn't steal your thread cj, but another tbi swap running and you guys were a big help. More questions to follow I'm sure.

Cuda

No worries about the thread - we are here to help (especially now). Do you know which alternator you have mounted on your motor??? I am guessing (based on a posted photo) that it is CS130 - should have four terminal connector with pins labeled S F L P and a stud labeled "Bat". Please confirm which alternator you have.

//RF

[cjracing15]

Originally Posted by 408cuda

Hope I didn't steal your thread cj, but another tbi swap running and you guys were a big help. More questions to follow I'm sure.

This is why I started this thread. I am glad you have got it running.

[rfmaster]

Originally Posted by cjracing15

This is why I started this thread. I am glad you have got it running.

Any updates since the last post????

Drove my truck for the first time in three weeks - engine runs silky smooth (everything works) with warm weather is here to stay for the next couple of days.

Aghhh - Found collector leak - you can hear it and there are carbon deposits were it leaks.

//RF

[cjracing15]

I finnally have an update. The truck runs great!! It took longer than I would have liked but it runs better than it ever did with the carb on it. I still need to get a vss from JTR and a chip from Tbi chips because of the cam I have in it. I also need to get a gromlet for the firewall installed for the computer wires. But other than that it is done. I wanted to get a vedio of it running but my camrea is not croperating at all so here are a few pics. Enjoy!

[cjracing15]

A few more.

The engine all together.







The interior put all back together


The choke as a check engine lite.

[cjracing15]

Ok here ya go. These are the only before pics I have.

[cjracing15]

Here are a few pics i forgot I took.

This one is the best I could do. I tried to get a pic of the internal baffel. This is for the pepople that had questions on why shoud you swap out the fuel tanks.


These last two are of the fuel lines that I used and how I flare them so they would have something to calmp to. The other ofcourse is the tank ready to be installed.




My problem ended up being the fuel selector valve. I guess that the 22 year old valve could not handle any extra press. going through it. I had to bypass it and it fired right up.

[pancake]

Hi everyone and thanks for all the great information. I am getting ready to convert my 4x4 rig to TBI and this thread is helping a lot. I have a few questions for you guys. I hope this is ok, I don't want to hijack the thread.

A little about the rig the TBI is going in:
78 blazer with a 350c.i. engine. I pulled the engine from a junk yard with no heads and rebuilt it. The rebuild is pretty much stock except a mid R/V cam and headers. I think the block was fuel injected before, therer is no cut out for a mechanical fuel pump. The heads I put on the block are not off a TBI truck and I know I will have to re-work the two inner intake holes to align with the heads. The tranny is a manual (SM 465) and a NP 205 T/C. This is a trail rig and will only see the road driving from the camp site to the trail head and will be on the trailer the rest of the time. I am thinking of putting a TH400 in this summer with a doubler.

I will be buying a used TBI setup. Should I get a pre 92 or will anyone work? I think Iwill buy a new aftermarket wiring harness from painless or Howell. Do I need to order anything specific for the harness?

Now for the TBI conversion questions:
1) The nuteral safty switch is re-wired so I can start the truck in gear if I need to. Do I just ground the N/S switch? Is it wire B-10? What do I do with the wire if I decide to go to the TH400?

2) After reading about the VSS I will be putting one on the conversion. The VSS conects top the tranny or t-case? Where can I get a cheap one? If I put a TH400 in will I need to change the VSS? The TH400 will have a manual valve body.

3) Where do I put the knock sensor?

4) Where I put the collant temp sensor?

5) I do not have A/C but would like to use the wire from the ECM to bost idel when I need to use the winch. Any sugestions how I would do this? Put in a toggel switch?

6) Which ECM should I look for? Serial #? and will I have to get it re-programed....new PROM?

7) I have a plastic fuel cell in the rig now. I might go to a stock fuel tank with the pump in it in the future. What external pump should I get to ust the fuel cell? Do you have a part number? Do I need a fuel regulator or is this built into the TBI? I do need a return line right?

7) I have also read about a charcoal canister? Do i need one?

Sorry for all the questions but I would like to do this right and you guys seem to know you are talking about. This is the best site I have found for TBI conversion information.

Thank you in advance for the help!!

[cjracing15]

First welcome to the board. Second I am glad that this thread is helping on your swap.

Now to try and answer some of your questions.

On your harness if you go aftermarket I would go with a howell. It is the best in my opion, if you want to go all stock there is one in the 73-87 classified section here for sale. (not mine. bigbolck 73 is the one selling it) It is complete. You will want to get a system from a 87-93 truck. It seems to be the most simple to use.


1) Yes I would ground this wire in your case.

2) It shoud be in the t-case. I bought mine from jags that run. They will have every thing you need to make your vss work

3) The knock sensor should be bolted in the center of the bolck. (does not mater what side) I will try to get a pic of mine for ya.

4) The cst should be bolted at the front of a tbi intake.

5) You can just use a switch for this for what you want to do. All it needs is 12volts to the wire.

6)Ecm # is 1227747

7) If it were me I would run a stock tank if it is all possible because of the reliabilty factor. GOOD (not cheap china made crap) In tank pumps just do not give much throbble at all.

8) You will not need a regulator unless you run a higher press fuel pump than stock. You will need to run a 5/16 return line.


I hope this helps you. Any more questoins just ask.

Oh and we like PICS.

[rfmaster]

Pancake welcome to the 67-72 board.

Your questions regarding TBI conversion are in the spirit of this thread and we are glad to help you with your project.

First things first - in your post you stated that you put a 'mild RV cam' into your rebuilt 350. Do you have specs for this cam???? This is very important as cam selection may make or break TBI conversion!!! I am not trying to scare you. Most RV cams are very tame, but there are couple parameters - LSA that make EFI tuning easy or difficult.

For a low cost TBI system I would look for (JY or running beater) 350 CID equipped 87-92 Burban or truck. These come equipped with 1227747 ECM's - grab everything that is connected to ECM harness:
CTS
EGRV + EGR
MAP
ESC
KS
Optional (Dizzy + coil) or find early full size dizzy from CCC equipped SBC car or truck. This is a subject for a long discussion and should be looked into separately.
TB (TPS + IAC + Injectors)
VSS and DRAC if available
CCP canister (optional)
Air diverter valve (optional)
relays, brackets, etc
O2 should be sourced new!


ECM (in trucks) is located just behind glove box and can (should) be removed intact. Please note that you can still use 305 equipped TBI system, but you'll have to do couple of upgrades down the road (EPROM, KS, Injectors). 1227747 ECM is very common, dirt cheap, has been hacked backwards and forwards, and can be easily updated (re-programmed)

For a little bit more work a car based TBI is an excellent foundation for a CARB to EFI conversion. Look for F-bodies 88-92 with (LO3) 305 TBI, B-Body both were equipped with LO3 (305) and LO5 (350) TBI systems. Early passenger cars TBI systems were based on 1228746 ECM. Car's emission requirements were (are) more stringent and more control and sensor lines were made available in '8746 ECM. These included ITS, CCP control, AC enabled and PS switch. In the 90's B-Bodies received an upgraded version of '8746 ECM - 16196395

From ease of conversion #1 1227747 from 350 CID truck (look for ASDU, ASDZ broadcast codes), #2 1228746, but this will require EPROM work, #3 16196395 from B-body, also will require some EPROM work or EBL conversion (#1, 2, or 3) for ultimate flexibility and ease of tuning.

I have sourced all my harnesses from JY donors - I can not comment on aftermarket harnesses. Either Painless or Howell should work just fine. If you have to pass smog - than you must have functioning AIR diverter you'll need harness that has connector that controls diverter.

Now for the TBI conversion questions:
Q1) The neutral safety switch is re-wired so I can start the truck in gear if I need to. Do I just ground the N/S switch? Is it wire B-10? What do I do with the wire if I decide to go to the TH400?
A1) With manual there are couple of options. For now just leave it open.


Q2) After reading about the VSS I will be putting one on the conversion. The VSS connects top the tranny or t-case? Where can I get a cheap one? If I put a TH400 in will I need to change the VSS? The TH400 will have a manual valve body.
A2) Get VSS from JTR - it is in line with your speedometer cable into trany.


Q3) Where do I put the knock sensor?
A3) Passenger side water jacket drain plug - just above oil pan rail. Be forewarned that it is best to remove this plug while engine is out of the engine bay. These plugs are known to rust-in and break while removing. Drilling a pilot hole and right size easy-out is only way I know to get them out! It is PITA.


Q4) Where I put the coolant temp sensor?
A4) CTS should be placed within 2- 3 inches of thermostat housing in intake manifold. Most after market manifolds have multiple suitable tapped holes.


Q5) I do not have A/C but would like to use the wire from the ECM to boost idle when I need to use the winch. Any suggestions how I would do this? Put in a toggle switch?
A5) This is a very easy circuit to implement. - Run a wire from winch relay coil to ECM AC requested input (ECM Pin-B8) line.


Q6) Which ECM should I look for? Serial #? and will I have to get it re-programed....new PROM?
A6) See discussion above, but if you get lucky...


Q7) I have a plastic fuel cell in the rig now. I might go to a stock fuel tank with the pump in it in the future. What external pump should I get to ust the fuel cell? Do you have a part number? Do I need a fuel regulator or is this built into the TBI? I do need a return line right?
A7) For TBI conversion you'll have to have fuel delivery system that works. You'll need three lines going to your gas tank. 3/8 fuel supply, 5/16” (or 3/8") and another 5/16" for vapor line - CCP. Tank must have internal baffles to keep fuel sock from uncovering. For external mounting I used Carter P74017. You do not need fuel pressure regulator - TB has a simple spring based FP regulator. Do not go crazy with high fuel pressure pumps!


Q7) I have also read about a charcoal canister? Do i need one?
A7) Yes, it keeps fuel vapors from escaping into atmosphere. With CCP fumes are delivered into TB and consumed instead of being lost.

[pancake]

wow...thanks for the quick responses...

A few more questions:
What is a:
DRAC, KS, Air diverter valve, ESC, and EGRV?

Sorry I am very new at this FI stuff

After further review, I might put an TBI adapter plate on my current manifold instead of changing intake manifolds. What are you thoghts on this?

Where does the Charcoal canister go? Is it in the return line to the fuel tank?

As for the camshaft..It is an Edelbrock R/V cam...very mild...do not have the specs with me but can let you know Friday.


If you recomend a factory harness.....I was looking on e-bay and found the harness, TBI, computer and all sensors off a 89 chevy truck. He also has the fuel tank. I might go this route...I still dont know for sure.. can you explain pros and cons of both??

I will be looking for a stock tbi fuel tank because my fuel cell does not have a return line. I would also like the truck to run when it is on its side, happened 3 times already

The 4x4 does not have to have emissions and is not street driven. What sensors should i get rid of and which ones do I NEED?

If I need to get the computer re-programed who can do this, or do I just order a chip for it?


Thanks again for all this great info and the fast replies. i hope this thread keeps going, it has tons of GREAT info.

P.S. Does anyone here live in Colorado?

[cjracing15]

Here is the pics I promised about the knock sensor.






ks I am gessing is Knock sensor

air diverter valve Is part of the emistions.

esc electroinc spark control.

egrv I am guesing is egr valve.

[cjracing15]

Originally Posted by pancake

wow...thanks for the quick responses...

A few more questions:
What is a:
DRAC, KS, Air diverter valve, ESC, and EGRV?

Sorry I am very new at this FI stuff

After further review, I might put an TBI adapter plate on my current manifold instead of changing intake manifolds. What are you thoghts on this?

Where does the Charcoal canister go? Is it in the return line to the fuel tank?

As for the camshaft..It is an Edelbrock R/V cam...very mild...do not have the specs with me but can let you know Friday.


If you recomend a factory harness.....I was looking on e-bay and found the harness, TBI, computer and all sensors off a 89 chevy truck. He also has the fuel tank. I might go this route...I still dont know for sure.. can you explain pros and cons of both??

I will be looking for a stock tbi fuel tank because my fuel cell does not have a return line. I would also like the truck to run when it is on its side, happened 3 times already

The 4x4 does not have to have emissions and is not street driven. What sensors should i get rid of and which ones do I NEED?

If I need to get the computer re-programed who can do this, or do I just order a chip for it?


Thanks again for all this great info and the fast replies. i hope this thread keeps going, it has tons of GREAT info.

P.S. Does anyone here live in Colorado?

I have read that people have had very good luck using adapter plates on there swaps.

The canister goes on the driver side is usually mounted on the fender or core support. Mine has three ports. One goes to the gas tank, one is a vent, and the other goes to the tbi.

If you are going to have to buy one anyway I would go with a howell harness. I used a factory harness becaue I had it already. One from an 89 truck will work you will still need a computer and a distrbutor. Like I said in the other post there is a complete setup on the site right now for sale in the clasified section.

The pro for me on using the factory harness was cost because I had it. Plus once you have to sort all the wires to fit it to your truck you will really get to know how the system works.

The con of course is TIME. It takes time to sort all those wires and then run them in a way that looks good. With the howel harness it is just about plug and play.

You just about need all of the sensors for the system to work like it is suppose to. You can get rid of the egr valve I guess but you will have to get a chip made wiht the egr turned off. But I think you are going to need that done anyway because of your cam.

Then that brings us to the computer and chip. I am useing tbichips.com . Check out that site. This guy is awsome.

Again how about some pics of your truck?

[rfmaster]

Pancake

DRAC - Digital Ratio Adapter Controller http://614streets.com/drac.html Not required if you are using aftermarket inline 2000ppm VSS.
KS - Knock Sensor ( http://www.sae.org/technical/papers/9004 88 )
Air diverter valve - A.I.R. used to control if AIR pump output is diverted into exhaust manifold or bypassed out http://www.freepatentsonline.com/3940928.html
ESC - Electronic Spark Control sends a voltage signal to the ECU. As the knock sensor detects engine knock, the voltage from the ESC module to the ECU drops, and this signals the ECU to retard ignition timing. The ECU will then retard the timing when knock is detected.
EGRV - EGR CONTROL SOLENOID


TBI adapter plate = it's OK, but be aware of possible leaks. For a clean installation on pre-87 heads I use Holley 300-49 Intake manifold (if you have funds).

Used factory harness from a pick your part JY is about $30-40, aftermarket new harness $300+. Factory harness is 20 years old - make sure that wires and connectors are in good shape. I have done couple of these conversions and have a collection of PED weatherpack connectors (Look for a connector kit on EBAY)

OEM GM sensors can outlast the car, but I I would not pay top dollar for them. Cheap is the word when it comes to used.

Gas tanks - you'll have to do a bit of research, but look for a tank of EFI burban (30 gal) that mounts behind axle. EFI tanks have baffles. You'll need 3 port fuel sending unit (and possibly in tank fuel pump, which is better than external)


For best drivability keep all sensors - unless you want to learn how re-program ECM on daily bases. Sensors: O2, MAP, TPS, CTS, and VSS. For off road you can omit AIR. Having CCP costs very little and prevents tank fume build up!

TBIchips can get you a chip - if you get ASDU code ECM it should work close enough to get you going.

//RF

[pancake]

after even more research....what is the deal with the o2 sensors? three wire? four wire? heated? Thanks again for all your help folks

[rfmaster]

If you are running headers - either three wire or four wire is must. You'll need to wire a simple relay controlled circuit to turn heater when ignition is on. Heated O2 provide correct O2 concentration in exhaust gas stream faster than old style single wire O2 sensors.
Optimally, four wire heated O2 provides a ground return wire back to ECM. Exhaust system may not provide low resistance path back to ECM. To avoid ground return loops fourth wire is used. (2x heaters, Gnd return, O2 signal = AFS-74)
In three wire O2 sensor you have 2x heater, O2 signal...

//RF

[pancake]

Since I do not have to worrie about emission control, do I NEED an Air diverter valve?

In my orignal post, question #1, for the N/S switch, rfmaster said to leave it open. Can you elaborate? open=not hooked up at all?

If I go with a stock harness, $ is always an issue, for the wires I dont use do I just cut them off?

I do have headers on my blazer. So I will need a 3 or 4 wire o2 sensor. I will also need to weld a bung into the header. I have read keep it within 12" of the head...is this correct?

Can you please explain how to"wire a simple relay controlled circuit to turn heater when ignition is on"?
I am no electrican but did google relay info and have a very basic understanding. Please correct me if I am wrong, but there are always open or always colsed relays....and a relay is just a switch operated by a current?? correct?

[pancake]

A question on ECM's....

for ECM 1227747 there are mant diffrent broadcast codes like ASDU and ASDZ?
A broadcast codes is specific to that vehical? example..a broadcast code ASDU is for a 1991 Chevy C-1500 5.7L V8 Auto, and a broadcast code of ASDZ is for a 5.7L automatic? Is this correct?
(See info below from http://www.cruzers.com/~ludis/c3xref.html#1227747)

Is a broadcast code the same as a PROM?

I have a manuel tranny in my Blazer. Should I not get a 1227747 with a broadcast code of ARHT or ASDW? Are they hard to find?

Or, does the tranny type of the broadcast code not matter in my situation?

Thank again folks for all you help!



1227747
Schematic

Application: 1987-91 truck 4.3 V6 TBI “Z” LB4 (exc. “S” & “T” body)
1990 truck 4.3 V6 TBI “Z” LB4 w/ MT (“S” & “T” body)
1990-91 truck 4.3 V6 TBI “B” LU2
1987-91 truck 5.0 V8 TBI “H” L03
1987-90 truck 5.7 V8 TBI “K” L05
1991-92 truck 5.7 V8 TBI “K” L05 w/o 4L80E
1987-89 truck 7.4 V8 TBI “N” L19
MEMPAK IDs: “Z”: ADWD, AKDX, AKSN, APAB, ATKX, …
“B”: …
“H”: ADTJ, AFDY, AJUK, ARPC, …
“K”: ACSU, ACSW, AKAL, AKAJ, AKAR, AMUR, ANLW, ANLX, ANLZ, ARHT, ARJT, ARJU, ASDU, ASDW, ASDZ, …
“N”: ANTZ, AZFT, …
CALPAK IDs: “Z”: 16051637

[rfmaster]

Originally Posted by pancake

Since I do not have to worrie about emission control, do I NEED an Air diverter valve?

In my orignal post, question #1, for the N/S switch, rfmaster said to leave it open. Can you elaborate? open=not hooked up at all?

If I go with a stock harness, $ is always an issue, for the wires I dont use do I just cut them off?

I do have headers on my blazer. So I will need a 3 or 4 wire o2 sensor. I will also need to weld a bung into the header. I have read keep it within 12" of the head...is this correct?

Can you please explain how to"wire a simple relay controlled circuit to turn heater when ignition is on"?
I am no electrican but did google relay info and have a very basic understanding. Please correct me if I am wrong, but there are always open or always colsed relays....and a relay is just a switch operated by a current?? correct?

N/S - Lieve end of that wire unconnected ECM Pin-B10 (Orange-black wire). In automatic equipped cars this line is grounded via P/N when transmission is set in Park or Neutral. This is done to compensate commanded engine idle speed in drive by about 50 to 75 depending on operating conditions.

If you go with stock harness - I would first lay out and id all connections - see my early post elsewhere in this post. IMHO I do not like to cut, but you can choose to remove unused circuits.

O2 positioning was critical for couple of reasons. First the O2 must be heated to about 600F to operate. Placing it further down stream tends to keep it below 600F. Heated sensor gets around this placement requirement. Another reason for keep O2 closer to the engine is what is known as transit response time. ECM operates close loop feedback system which takes into account response delay times. I can go on further into control system theory, but ideally observation points need to be within near proximity of the process to keep close loop operation stable.

I'll post simple relay circuit schematic - it is a bit late tonight.

Automatic calibration or broadcast code BCC (EPROM) can be easily adapted to manual transmission duty. As is automatic calibration is not ideal, but it will get you going. There are several calibration tables that must be changed to make manual transmission operation smooth. This is another subject area that you'll have to research. For now hunt for a 350 based BCC 1227747 ECM as your starting point. .

Relay allows small control current to control large load current.

//RF

[pancake]

Here are the specs for the cam shaft in my 350:

Summit® Camshafts
Camshaft, Hydraulic Flat Tappet, Advertised Duration 252/ 262, Lift .398/ .420, Chevy, Small Block, Each

[pancake]

195/202@.050,.390/.410" lift stock?

[rfmaster]

Heated O2 control circuit.

Summit K1101 cam is a very mild mannered cam shaft. I have heard (never used one myself) that it (Summit K1101) works well with TBI. For a stock TBI EPROM idle vacuum must be around 16 to 18 inch at 600 RPM. Large overlap cams or narrow LSA kill idle vacuum for high RPM power. Since TBI relies on MAP sensor to determine volumetric efficiency significant deviation of vacuum at various operating points (RPM/MAP) will result in incorrect baseline fuel delivery. ECM can compensate, but if it is too far off - engine will run rather poorly if not at all.

You should be fine with this cam.....

//RF

[pancake]

Thank you for the relay circuit schematic. I should be able to do that? Can I get these at Radio Shack or do you know of a better place?

I found a guy on E-bay that has a complete unit for $400.00:

It's in a 1990 Chevy 2WD Truck

TBI aluminum intake manifold w/ temperature sensor and EGR valve
Throttle body w/ TPS (throttle position sensor) and IAC (idle air control) valve, Distributor
Ignition coil
EGR solenoid
Sensors including the ESC (electronic spark control) and MAP (manifold absolute pressure) sensor with brackets, knock sensor, and oxygen sensor
Air cleaner spacer w/ valve cover breather tube
Air cleaner assembly including flexible air intake hose
Power brake booster vacuum line/hose
Complete engine wiring harness
ECM engine computer #1227747
Electric fuel pump w/ sending unit
Fuel lines
Nuts & bolts

and will add the fuel tank out of an TBI Suburban for another $40.00

with shippiny to Colorado for everything is ~$500

Can you guys think of anything else I will need right now besides a CCP?

Thanks again for all the help and quick responses!!

I will be putting up pictures of the Blazer soon, as well as the TBI parts when/if I get them.