86 Silverado Father and Son project
 

Moved from the engine and drivetrain section because this turned into a real project!



I am "helping" my son build a truck to drive. So we purchased a 86 swb that needs an engine. Today we purchased a car with a donor engine 92 Buick roadmaster with a 5.7 tbi engine and I think a 700r4 tranny. The first question can I do a direct swap and use the ecu and harness and keep the throttle body? or would be better off throwing the old carburator and intake off the oem 305? Has anyone done this type of swap? can we use the 700r4? I hope to use the serpentine belt setup and I know we probably need to address the fuel supply to the motor. What about emission crap? Can I just chuck it all in the trash? BTW,The fuel inected motor runs good and I think it would be more economical and reliable than a carb. Suggestions? Thanks,
Mike

Here is the truck:
http://i14.photobucket.com/albums/a3...ck/86chev1.jpg
here is the donor engine:
http://i14.photobucket.com/albums/a3...uck/buick1.jpg
http://i14.photobucket.com/albums/a3...uck/buick2.jpg
http://i14.photobucket.com/albums/a3...uck/buick3.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

that setup could be a direct bolt in. what trans is currently in the truck? if its a 9 inch shaft th350 the 700r4 is a direct bolt in driveshaft will even work. same if its already a 700r4. i would leave the engine as is with the exception of the catalytic converter. the tbi runs great and it will get decent mileage. not gonna set any speed records but will be reliable.you can do the normal upgrades to get a few more ponies out of it. the serpentine setup is definately the way to go. basically drop it in as is. the only issue will be the speed sensor the car has versus a mechanical speedo drive. but there are adapter available to address that too

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Thanks for the reply Cableguy, I think the tranny was a 350 TH longtail. What about wiring? Is it pretty much plug and play using the TBI harness and ecm? Does this vintage use a high pressure fuel pump located in the tank? Or is it mechanical? I think we are going to start pulling the engine and tranny today. I'm wondering, do you think we can pull it as an assembly, or will we need to seperate it at the flywheel? thanks for your help,
Mike

here is a pic of the original tranny:
http://i14.photobucket.com/albums/a3...ck/86chev4.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

the fuel pump is easy. its actually a low pressure pump. it is electric but only 15psi. as a matter of fact go find at 86 or 87 truck with tbi and steal the tank out of it and u will have a bolt in deal. just look at some trucks with that setup on it to get a good idea of the wiring. its fairly simple just need to run the powers etc to the proper places. just be very careful when you take the harness out of the car not to break anything and keep track of all grounds to ensure they all get hooked up in the truck. pull all the plastics and radiator etc out of the car pull the fan off and the serpentine brackets just make sure u get all the bolts out. the bolts are all in the same places as all of the older sbc's tho holes on the block and a couple on the heads. drop the tranny crossmember and the engine and trans should come out as a unit. they will definately go into the truck in one piece lots easier to deal with that way.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

oh and i almost forgot. u will be using the power steering lines from the truck but you hafta swap the adapters out of the pumps. where the line screws into the power steering pump is removable. u need unscrew the line then unscrew the fitting that the line screws into. and swap them from one to another so the threads will match. be careful when u pull the fitting theres a spring it will pop out at you.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Thanks again Cableguy! I am hoping this goes smooth. I noticed the a/c compressor is in a different location on the truck. I defenitely think the serpentine belt is the way to go.

I am a little worried about the fuel pump/tank setup. The truck has duel tanks on it. I don't know if it's possible to use both original tanks with the original switching system?

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

the easiest thing to do would be to find an identical truck in the junkyard and rob the fuel system stuff.you might lose one tank but i know for sure there were fuel injected trucks with dual tanks. just would hafta see how its setup. i would however at least pull the pump and stuff out of the car just to have it even if its just a spare. its a 15psi electric in tank pump. relatively cheap. they were used in a ton vehicles. but i would find tanks out of a newer truck and steal the whole setup it will bolt right in if its an 87 or so

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Made progress this afternoon. We got all the mechanical unhooked and most of the electrical. I'm still trying to figure out what all we need to keep from the 92 harness. The plan is to remove the whole harness in tact and then remove what we won't need on the 86. I tried to label everything where it goes.
I was pretty impressed with how clean the engine and tranny is. There was no noticeable leaks anywhere. The odometer shows 223k miles but the engine still runs real good and the trans shifts good. Hopefully, all will go smooth. Here is a pic:
http://i14.photobucket.com/albums/a3...uck/buick4.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

good deal your just about there now only a few more bolts and the whole thing is out and on the ground. its a lot easier to sort the harness out once its laid out and untangled

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

More progress! We got the donor engine out today! (thanks Garrett for the help). Anyway, Here are the pics, it seems there are a bunch of extra wires to get rid of. Notice the number from the ecm. Hopefully, I can try to start sorting out the harness tomorrow.

http://i14.photobucket.com/albums/a3...uck/buick5.jpg
http://i14.photobucket.com/albums/a3...uck/buick6.jpg
http://i14.photobucket.com/albums/a3...uck/buick7.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Small progress. I pulled all the rest of the wiring from inside the donor, pulled the fuel tank and all the lines. Hopefully, I can use some of these parts. The car is pretty much ready for the scrap yard. We'll probably wait until the engine is running before hauling it off. Just in case we need parts off it.
Then started trying to seperate the harness and figure out the wiring. I'm totally lost on how this should be done. I noticed most of the TBI upgrades are guys just adding the system and not starting with a complete motor and tranny that was running. Maybe, I'm just lazy or crazy but I thinking I'm going to just stick it into the truck and make the connections in the truck.

I got the bulkhead connector off and tried to get the gooey glue off (messy). I hoping to leave the engine harness pretty much the way it is and intergrate the necessary truck connections like the temp, oil press, starter and anything else it takes. The truck harness is covered in oil. I guess the PO had a massive leak and it covered every wire in there. Photos:
http://i14.photobucket.com/albums/a3...uck/buick9.jpg
http://i14.photobucket.com/albums/a3...ck/buick13.jpg
http://i14.photobucket.com/albums/a3...ck/buick12.jpg
http://i14.photobucket.com/albums/a3...ck/buick11.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Update:
We decided to bypass the wiring "problem" for now. We just finished stabbing the motor this evening. (no time for pics). It looks like the tranny is sitting back about 5 - 6 further than the original tranny. I'm not 100% sure yet but it looks like I may need to move the cross member back and get a different driveshaft. Man, today was the first time I crawled under the truck. I knew from looking at the engine and bay that the PO had an oil leak but, man the whole under side of the truck is COATED with oily slime. I wish I had a pressure washer. I am going to see about borrowing one. I hope to get some photos tomorrow.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

there should only be a 3 inch difference between the th350 and the 4l60 mounting point. 2 inches if your trans is a 700r4 which I think it is. if your th350 has a 9 inch tail shaft the driveshaft should swap right over. if its a 6 inch shaft your about 3 inches short but getting the driveshaft out of a truck that came with a 700r4 stock shouldnt be a problem

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

I'm not sure what tranny the truck came with. It's in the pic above in the bed of the truck. And I don't have a clue what the car had in it. I will move the cross member tomorrow and try to figure out how much too long the driveshaft is. You said the difference could be 2 inches for the 4l60? Would it be possible to find an OEM driveshaft? Maybe at a salvage? I could cut it down at work and re-weld it if necessary. I have access to TIG welder. It may need to be rebalanced though right? Thanks for your help!,
Mike

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

measure the tail shaft. see if its 6 or 9 inches. its a th350 in the bed of the truck.measure just the tail housing thats bolted on with the 4 bolts. make sure the clam shell mounts bolted to the engine from the car are the same as the ones on the motor from the truck.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

I didn't change the mounts you are talking about. I thought they only made one hole pattern on those. The dist. looked pretty good in relation to the firewall, but it was dark and late by the time we got done. Hopefully, more progress today after work. Thanks,
Mike

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Update:
We worked on the truck for an hour or two. Not much in the way of progress. I was able to find out it looks like we won't need a different drive shaft. I stuck the original in the tail shaft and raised it up to the rear diff. and it looks to be a pretty good fit. (I can't find the hardware for the u-joints, hope I can find some replacements). I don't know for sure how much slack is needed for suspension travel? Anyway, I am putting off the need to get started on the wiring. I was able to get all the broken studs out of the d/s exhaust manifold. (that was a pain!) I will try to get some pics. I was able to weld washers to the studs (several times) heat it up and get them out. I still have to weld the bung in the d/s for the o2 sensor.

This project has really tested my patients, so far I am losing big time! So far I have had to fight with the motor mount bolts, the tranny cross member, the exhaust manifold bolts and on and on. This is what happens when you don't do any serious wrench turning for 15 years. I hope my son doesn't get half of my short temper!......here is some pics.

engine in its new home
http://i14.photobucket.com/albums/a3...ck/86chev5.jpg
http://i14.photobucket.com/albums/a3...ck/86chev6.jpg
Cross member needs to move<----- 3"
http://i14.photobucket.com/albums/a3...ck/86chev7.jpg
Driveshaft front
http://i14.photobucket.com/albums/a3...ck/86chev9.jpg
Driveshaft rear (I need caps too)
http://i14.photobucket.com/albums/a3...ck/86chev8.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

good deal. if possible slide the carrier bearing towards the trans some and get the yoke into the trans a bit further. other than that looks good. just gotta do the wiring now

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

also those u joint straps are in the help section at any auto parts store.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Thanks, now I know what motors in my truck, that looks just like my engine and it powerful.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Thanks for the info, If I remember right they have something like a 5/16-24 cap screws too. I should be able to check that pretty easy.

Also, this truck has a one piece driveshaft with no carrier. I think that there is only about an inch of travel from butted up tight to where it actually will ride.

On the wiring, I am going to wait till I have all the things I know or kinda remember how to do first. Then move on to wiring.

Mike

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

lol it wont be too bad. the bolts come with the strap in the package so dont worry about finding em. is it a short bed truck?

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Yep, it is a short wide.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

the d shaft will go into the trans a bit further once u set it down on the crossmember with a mount isntead of sitting up on the pan. ideally you would want the shiny part of that yolk all the way in the trans. it will be close enough once you set the trans down

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

I made a threaded bung out of SS and welded it to the truck manifold.
Pics of progress:
Before
http://i14.photobucket.com/albums/a3...k/86chev10.jpg
After
http://i14.photobucket.com/albums/a3...k/86chev11.jpg
http://i14.photobucket.com/albums/a3...k/86chev12.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

I'm working on all the mechanical issues with the engine install. But, I am starting to try to figure out some of my wiring and gage problems. I'm curious if any of you guys left the original sending units if you did this type of swap? I am planning to install the original truck oil senders and the temp, I just don't know about the ones from the car engine? Does the ecm need to see info from these? I will have to come up with tees if that is the case.
Here is the car senders:
http://i14.photobucket.com/albums/a3...k/86chev13.jpg

Here are the truck senders:

http://i14.photobucket.com/albums/a3...k/86chev14.jpg

I also notice there are some electical components I don't know what are?
I know one of these is a fuel pump relay....so what are the other pieces?
do I need them?

http://i14.photobucket.com/albums/a3...k/86chev15.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Mike

First photo.

The T combo.
One of the two sensors is a pressure transducer which is used for oil pressure gauge while the other is an oil pressure switch which is used for idiot light. Take a close look at both - look for GM part numbers. The temp sensor on the right should be screwed into the driver side cylinder head. Remove car sensor and replace with truck version. IMHO, now is the time to get replacement sender as old ones can develop a leak.

Second photo

Combo bracket - this bracket was mounted on a passenger side fender skirt (B- Body) and is used to support ESC module, ?, couple AC circuit relays and ECM fuse holder. Electronic spark control (ESC) module is used in conjunction with knock sensor (KS) to provides a voltage signal to ECM when engine knock is detected. ESC module is analog signal conditioner - filter. Depending on severity of detected knock it will pulse 9 volt output to ECM, indicating presence and persistence of engine knock.

//RF

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

RF,
You mentioned that one of the relays is for the A/C controls? Is this to kick the compressor on? I assume I will need to tie this into the truck harness?

Another thing came up today that for some reason I never noticed. This transmission has an electrical speed sensor and the truck has a mechanical cable that runs the speedo. Is there a simple solution for this? Or let me rephrase, is there a cheap solution to get the speedo to run?

We made good progress today on the install. Finished the exhaust, changed out the sending units, moved the tranny cross member, put the new straps on the rear U-joint. It looks like I will need to drill some holes for the cross member. 2 bolts on each side lined up. Also, the driveshaft seems to be just about the right length. Hopefully, we can wrap up all the mechanical this week and get to wiring this weekend. This is slow going when you only have an hour here and 2 hours there. Here are some pics:

http://i14.photobucket.com/albums/a3...86chev21-1.jpg
http://i14.photobucket.com/albums/a3...k/86chev18.jpg
http://i14.photobucket.com/albums/a3...k/86chev20.jpg
http://i14.photobucket.com/albums/a3...k/86chev19.jpg

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Mike

Regarding AC control relays and circuit.
AC control circuit will require some rework. I have a FSM for '91 B-body which covers AC circuit in detail. I do not have the same manual for your truck! If you can get your truck information than we have a good chance of putting a combo harness that will work.

Regarding speedometer.

Bad news - money involved. To get a fully functional spedo - VSS will require procurement of two parts. You have to get a mechanical speedometer driven gear housing - that's what plugs into transmission in place of your electronic vehicle speed sensor (VSS) from an earlier 700R4 equipped car or truck from JY or a local tranny shop. Try to get aluminum one - they last longer. Depending on tire/rear end ratio you'll have to change driven gear to get speedometer to read correct speed. Furthermore, to keep ECM happy an inline bolt-in VSS from JTR will have to be procured. TBI equipped cars and trucks used two-pulse (2000 pulses per mile) square wave VSS (it's a reed switch) through 1992. You can read a full explanation here:
http://www.jtrpublishing.com/Pages/S...eedometer.html

A lower cost VSS is available from Summit made Rostra Precision Controls 250-4153
http://www.summitracing.com/parts/RPC-250-4153/
Specs for this part - number of pulses per revolution are not available. I did not use this part before so I have no first hand experience. Perhaps, worth a call to summit tech line.

Another rely cheap inline VSS is made by SCS/Frigette 208-3606 - again no first hand experience with this one.

More discussion with VSS retrofitting can be found here:
http://www.binderplanet.com/forums/s...ad.php?t=50649

//RF

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

RF,
I am wondering if I tie truck A/C control wire(s) into the circuit that goes to the ecm for the a/c would that then control the relay to fire the a/c? What info about the truck is required to construct the harness you are talking about? Do you do this type of work? I am assuming you are a EE....is it just a hobby?

Regarding the VSS, it looks like this with the proper gear ratio and tire size would be a direct replacement:
http://i14.photobucket.com/albums/a3...tegral-VSS.jpg

It is pretty pricey at a $101 plus the shipping. I wonder if any of the early 90s
burb or blazer instrument panel with necessary wiring would solve the speedo issue? As always, thanks for the help!
Mike

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Cableguy,
I tried to use the high pressure power steering line from the truck it would not mount up to the car engine. (not because of fittings more because of wrong routing) I'm wondering if I need to get a hose that will fit say a 90-92 burb or blazer?

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

you could try to bend the line to make it fit. if you bend it slowly and your careful not to crack or kink the line you can probably move it enough to make it work for ya. the other option is to have a hose made. you would take the truck hose for the steering box side and the car hose for the pump side and have them use each end and make u a new hose.

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Cableguy,

I tried bending it to fit. It still needs a lot more than I could get out of it. I call local autozone I'm hoping the hose for a 90-92 suburban will be a direct replacement. I will let you know. Thanks,
Mike

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Here is great article on a TBI swap.
http://users.sfo.com/~eagle/howell.html

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Mike

The four pulse unit will not work very well with your car ECM. Assuming that 4 pulse VSS is a square pulse (On-OFF vs. AC) type will cause ECM to detect twice the actual speed and depending on ECM calibration fuel cut off will occur at much lower actual speed (around 55 MPH vs. 110 MPH). Not good.

Early 90's trucks & SUVs used the electronic vehicle speed sensor and DRAC module for electronic speedometer. That system is a kludgee mess as DRAC provided different frequency pulse signal to various sub systems (ECM, Spedo, Anti-lock brake computer). This simplest solution is to get 2000ppm inline VSS and non electronic speedometer gear housing.

Yes, I am EE - non automotive, but I have a lot of respect for auto boys since their environmental requirements exceed industrial ratings and probably on the par with mil specs.

AC wiring requires a bit of combining of truck controls with your new ECM.

//RF

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

RF,
What would you suggest doing with the vss? I guess I need to get the aluminum housing you spoke of and the inline electronic vss? Any idea what part numbers? thanks,
Mike

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Mike

You'll need the following:

Speedometer Driven Gear (43)
Speedometer Housing & Support Bracket (44)
Speedometer Housing O-Ring (42)
http://www.tcsproducts.com/images/st..._schematic.pdf

All three items can be sourced from JY. The only catch is get a correct driven gear that gets speedometer cable to turn at 1000 tire revs/mile - this is straight forward and several handy references are availlable. The following links are will provide you with a good reference information:

Look for part # 54 (P)

http://www.partshp.com/speedometer_gears.htm
and
http://www.73-87.com/7387garage/drivetrain/speedo.htm

VSS
I think I covered this subject extensively in prior posting.

Attached photos capture my setup - I run this my conversion. That yellow module is a JTR 2000PPM TBI VSS bolted to speedometer housing and speedometer cable is bolted into VSS output. Photos were taken at an awkward angle - sorry.


//RF

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Which one of the senders is for "idiot" light and which one goes to the pressure gage?

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Mike

1) Fuel Pump relay wiring

Fuel pump relay socket on a 91 B- Body should have the following wires:

1) black-white (16AWG) | coil ground
2) dark green-white (16AWG) | coil hot - pulled by ECM to +12 V to activate FP relay.
3) Orange (10AWG) (NO - 87)| Battery hot (there should be 20 Amp inline fuse)
4) Red (16AWG) (NC - 87a)| Fuel pump test (4" pig tail with a blade connector)
5) Gray (10AWG) (COM - 30)| Switched Fuel Pump line - this should be connected to FP + terminal.

2) Ignition On Power
I end up wiring a simple relay circuit (see Painless Wiring switched fuse box #70107 for electrically challenged) that gets energized when ignition is on or in start position. For this you'll have to probe your fuse box and find a spare tap port (there should be several ) that remain hot when ignition key is in run and start. This is very important to make sure that this port STAYS hot during cranking!!! Otherwise your ECM will never get a chance to fire injectors during cranking.
http://i226.photobucket.com/albums/d...ng20090202.gif

3) AC control circuit

Will have to dig into it since B-Body ECM compensates idle RPM when AC is commended to ON. It makes for better idling setup.

//RF

Re: 5.7 TBI in an 86????? Anyone done this swap??
 

Thanks RF for you patients with this novice on this wiring subject. I was able to figure out a few things about the truck wire harness but still have a long way to go.

While your on here, which one of the oil sending units was the one for the idiot light? I need to get rid of it and put the original one for the ecm back on there.

right now, I am searching ebay to find some fuel line inline pump filter clamps etc. BTW, how did you tie into the tank? this truck has dual tanks and I assume there is a switching valve under there....so I guess that is where I cut the 5/16 line and tie into with the inline pump?