[cruiser enthuiser]

I am posting up progress of my TBI conversion for my carb'd Chevy 350 in my '68 FJ40. I know there is a lot of information on this forum relating to this subject already and I have found it very useful. However, I am a total newb with this stuff and thought others (who might be newbs too) might find something useful from my project. Also, I hope some TBI Veterans will chime in and offer advice.

Here's a pic of the engine now. It's dirty, the PO let it sit for a long time. Fortunately, the mileage is low, only about 4k. The carb is a Carter AFB - it has never run well and I hate messing with it. After much reading, TBI seemed like the easiest, most economical way to get reliable EFI.

[cruiser enthuiser]

During my research on TBI swapping I found this article and after reading it I decided that DIY EFI was something I could tackle:

How to install GM TBI on any Chevy V8

I started searching for a donor and almost immediately found an '88 Suburban on Craigs List that was being parted out. The engine was still complete so I grabbed it, the harness and ECM (computer) for $100.00. I was pretty stoked with the ease of the find.

[cruiser enthuiser]

I blasted the worst of the crud off at the car wash and started pulling stuff off. At this point I'm wasn't even sure which sensors do what, but if it was questionable I pulled it to be sure. What I am sure I need is: MAP (manifold absolute pressure) sensor, temp sensor, knock sensor. Also pulled electric spark control module and distributor.


Pic of the intake as I stripped it down.

[cruiser enthuiser]

In order to adapt the TBI intake manifold to my engine the four center bolt holes of the manifold have to modified because the angles are different. I saw that others have done this themselves but I was leary of trying to machine anything and screwing it up. I took it to a local machine shop and they said, "You got a Dremel?"

I said, "yeah."

"Do it yourself, it's easy," he said.

Since I was there I had the manifold hot tanked. Here's what it looked liked after.

[cruiser enthuiser]

I set up my old Edelbrok intake next to the TBI one and compared the angles. I tried to use a protractor to determine the angle that I would have to bore but this proved impractical. I tried to drill the holes on my drill press but the manifold was akward as hell. Ultimately, I eyeballed and used a hand drill and hogged out the holes and that worked pretty good. I test fitted the intake half a dozen times and finally did break out the dremel to clean up the holes. They are very elongated and it looks a little odd when bolted up but it shouldn't effect anything adversley (right?).

[cruiser enthuiser]

Because the angle that the bolt enters the manifold to bolt to the head is now different from the surface of the manifold it was neccesary to cut an angled recess. I read somewhere that it's 18 degrees. I see that others have fabricated special angled washers but I wasn't crazy about that idea. Instead I used the Dremel again for cutting the recess. The little cutter head was about the right size diameter. It was slow going but I think it came out pretty good. Is it 18 degrees? I dunno but the test fit came out nice. It's hard to see in the picture.

Oh, and I did paint it...VHT flat aluminum with some clear coat.

[cruiser enthuiser]

Here's where I am at now. I carefully cleaned the throttle body and have partially reassembled the intake manifold. I will bolt it up to the engine in the next few days. There's still a long way to go including installing a new electric fuel pump, special fuel sender with a return, and fuel lines and of course the wiring!

[Trollhole]

Great job. I love to see parts that are all dirty cleaned up to look new again. Pluss they are so much easier to work with.

I don't understand why people don't have parts hot tanked more.

[Bomar]

Nice work and great find on the burb engine.

[cruiserjunkie]

Add this to thread to must watch colum Thanks for the info

[cruiser enthuiser]

Originally Posted by Trollhole

Great job. I love to see parts that are all dirty cleaned up to look new again. Pluss they are so much easier to work with.

I don't understand why people don't have parts hot tanked more.

It was $20 well spent IMHO.

Thanks for the compliments.

[rsc71]

i got a 89 blazer for my tbi for 400 and sold the axles for 300.i am transplanting the whole motor and harness though so will be easier for me.looks good so far!! there is an IH web page that is real helpful on TBI swaps
Parts Needed For The Gm Conversion - Binder Bulletin Forums

[cruiser enthuiser]

Originally Posted by rsc71

i got a 89 blazer for my tbi for 400 and sold the axles for 300.i am transplanting the whole motor and harness though so will be easier for me.looks good so far!! there is an IH web page that is real helpful on TBI swaps
Parts Needed For The Gm Conversion - Binder Bulletin Forums

Great link! Very helpful with the part #'s and prices. Thanks!

[allan man]

I have been planning on doing this myself,this is like a miracle that someone like you posted it, i will be paying close attention to your thread as far as parts,cost,donor vehicle, especially all those wires...what color what goes where, heck ill make sure i get a 88 suburban unit myself...and thanks for sharing

[AKcruiserfreak]

Looks good! I'll reference this thread when I go to a TBI V8.

TK

[Downey]

I looked at the Binder Bulletin, I think it's a good starting spot, but does not take you far enough towards completion. I would additionally want one of our instruction manuals (freebie) because it is more detailed with regard to the harness, specifically the 6 wires that go from the GM computor to your Toyota vehicle (in addition to all the wires that go from computor to engine). The Binder Bulletin also mentioned some things we have not found it necessary to do??????

[Mr. Notorious]

Nice, I'll be watching this thread!

[cruiser enthuiser]

Originally Posted by Downey

I looked at the Binder Bulletin, I think it's a good starting spot, but does not take you far enough towards completion. I would additionally want one of our instruction manuals (freebie) because it is more detailed with regard to the harness, specifically the 6 wires that go from the GM computor to your Toyota vehicle (in addition to all the wires that go from computor to engine). The Binder Bulletin also mentioned some things we have not found it necessary to do??????

Thanks for that input. At this point I am gathering all the information on this conversion that I can get my hands on. Is there a PDF version of this manual Jim?

Thanks - Ed

[Mr. Notorious]

I'm still a newb at this swap so I must be missing something obvious, but why didn't you just get an adapter plate for the throttle body to the 4 barrel intake manifold you had on there already?

[too tall]

Originally Posted by Mr. Notorious

I'm still a newb at this swap so I must be missing something obvious, but why didn't you just get an adapter plate for the throttle body to the 4 barrel intake manifold you had on there already?

Good point . Looks great though at any rate . What are you hoping to gain from this conversion?

[cruiser enthuiser]

Originally Posted by Mr. Notorious

I'm still a newb at this swap so I must be missing something obvious, but why didn't you just get an adapter plate for the throttle body to the 4 barrel intake manifold you had on there already?

I thought about that option. After doing a fair bit of reading and web searching on the subject I came to this very unscientific conclusion: GM designed this intake to work specifically with their TBI system. Would bolting the throttle body to an intake manifold designed for carburation yield equal performance? I have no way to know so I'm siding with GM on this one. If it didn't make a difference I don't think they would have re-designed it. Plus, I already had the manifold from the donor engine and I think an adapter plate is about $60.

Maybe someone else can offer additional insight on this?

[cruiser enthuiser]

Originally Posted by too tall

Good point . Looks great though at any rate . What are you hoping to gain from this conversion?

There are a number of obvious benefits for electronic fuel injection like improved off-road performance, fuel efficiency, no more carb tuning, etc. For me the most important thing is reliability. I want to turn the key and hear it purr (ok, maybe not purr but rumble softly)...everytime.

[3doghouse]

Great thread, please keep us posted!

[Mr. Notorious]

Good Enough answer for me! Did you pick out the fuel pump yet? I think I may copy your part numbers

[cruiser enthuiser]

I have made frustratingly little progress on my TBI conversion during the holidays - lots of family in town and lots of commitments. Every time I thought I had a few free hours to work on the Land Cruiser something would come up . As a result my intake manifold is still sitting on the bench.

That's not to say I didn't make some progress. I continued to read all the information I could find on TBI conversions and spent some more time identifying and cleaning parts.

Below: Knock sensor - this threads into the water drain plug on the side of the block by the starter.

[cruiser enthuiser]

Electric Spark Control Module on left, Manifold Absolute Pressure Sensor on right.

Pic Below that is oil pressure switch.

[cruiser enthuiser]

I have given a lot of thought to the wiring harness and whether to go with a Painless or use the stock GM harness. Here's the argument as I see it:

Painless= easier installation with new wires/connectors
GM= great price! PITA installation with old wires/connectors

I have nearly zero experience with automotive wiring until this project, so the idea of tearing into the stock harness is intimidating as hell. $370.00 for the Painless may save me weeks (or months) of cursing and spitting in my driveway.

On the other hand, there is loads of information out there from others who have used the stock harness including wiring diagrams, etc. and I would like to put that $370 towards something a little more sexy (new shocks would be nice!). With that in mind I started looking at the harness.

The connectors are all very self explanatory as to where they are supposed to go. I connected everything I could on the intake manifold and labeled it. There are a few cut wires and I am very concerned that the connectors to the fuel injectors look a bit melted (kinda tough to see in pics). Should I find new ones?

[cruiser enthuiser]

Pics of what I labeled so far. Tomorrow: install the new manifold!

[cruiser enthuiser]

I bolted on the TBI intake manifold today. I used these funky bolts that were on my old Edelbrock. They have a small 12 point head which worked out nicely because of the very tight space on a couple of the bolts. Hooked up as much as I could for today. Need to deal with the new fuel system next.

Couple pics to show the progress. Notice I installed the oil pressure sender first for ease of access.

[cruiser enthuiser]

Manifold installed.