GM EFI... long shot but.....

[DeckSetter]

just thought I'd ask if anybody knew...

My coworker has an '88 Chevy truck, 350 automatic. The previous owner of the truck took out the fuel injected engine (maybe blew it up? dunno, truck has 190k) and replaced it with an older carb'd engine.

Problem is, the carb is way too big and somebody used the carb on a racing engine and took the whole butterfly out so now it has no choke. Brilliant, too bad it's a street truck and Indiana is cold in the winter. He'd prefer fuel injection.

I have a complete '93 GMC van, 350 that threw a rod. Will the '93 EFI setup work on the older engine? Are the computers the same? I think the truck wiring is intact except the engine harness, would the van harness work? Is the '93 computer the same as the '88?

Any info? I just need a starting point...

[BadAssPerformance]

Although they both shoul dbe TPI, I think that they are totally different wiring. Would be best to pull everything from the van if you want to try to EFI it. Way easier just to buy a street carb tho.

[turbovanman²]

All 350 TBI's up to 95 will work BUT there is computer differences, EGR control, spark control and air cleaner differences but are interchangeable. Van to truck wiring harness, totally different but in a pinch, I guess you could make it work. The van puts the computer under the drivers seat, the truck is behind the glovebox.

You can use the 93 computer as long as you use 93 spec components, IE EGR controls etc.

Also, depends on what year engine the truck now has, the TBI intake has the newer angle bolt holes, starting in 86.

[DeckSetter]

Also, depends on what year engine the truck now has, the TBI intake has the newer angle bolt holes, starting in 86.


I believe the engine in the truck is older, so that pretty much rules that out. Doh!

Thanks!

[turbovanman²]

I believe the engine in the truck is older, so that pretty much rules that out. Doh!

Thanks!

I think you can ream out the holes on the intake to work, surf the net for info, I can't remember.

[JDAWG]

honestly i dont understand why people do this (not meant torwards the op), lets just rip out all that fuel injection junk and slap a big carb on there (which is way inefficent). Carbs suck! How hard is it to figure out how 5 sensors work? Sorry to whore your thread.
but i thought the heads were different from the carb to fuel injected engines, I could be wrong

[88_pacifica]

OK, here's the dealie yo...

First of all some verification needs to be done. There are 2 different "styles" of 350 motors offered in the "80's era." I'm guessing this V8 is of the 2 piece rear main seal variety since it's "carbed," but you have to verify this. The intake mani bolts holes are in the same locations, but the angles that they are drilled in is different and more "vertical" on the '93 as Simon said. This didn't affect anything really other than make working on them a little "easier" supposedly.

This first was done on the TPI Camaro's and so on in '87-88 IIRC. So, this is important to verify for proper sealing purposes. Secondly, the newer motor and electronics(thrown rod engine) are probably reverse cooled (aka- heads then block) whereas the first gen is not, (pre '88). This may not sound like a big deal, but it's NOT like our 4 cyl because the whole head has different flow/cooling ports/runners so you can't just "switch" the pumps.

The electronics are designed for this so it will totally screw up the sensors and cooling stats. Find out what it has first and post back up your findings. Oh, and to verify by looking which you have you will need to look at the crank.

http://en.wikipedia.org/wiki/Chevrolet_Small-Block_engine

[turbovanman²]

OK, here's the dealie yo...

First of all some verification needs to be done. There are 2 different "styles" of 350 motors offered in the "80's era." I'm guessing this V8 is of the 2 piece rear main seal variety since it's "carbed," but you have to verify this. The intake mani bolts holes are in the same locations, but the angles that they are drilled in is different and more "vertical" on the '93 as Simon said. This didn't affect anything really other than make working on them a little "easier" supposedly.

This first was done on the TPI Camaro's and so on in '87-88 IIRC. So, this is important to verify for proper sealing purposes. Secondly, the newer motor and electronics(thrown rod engine) are probably reverse cooled (aka- heads then block) whereas the first gen is not, (pre '88). This may not sound like a big deal, but it's NOT like our 4 cyl because the whole head has different flow/cooling ports/runners so you can't just "switch" the pumps.

The electronics are designed for this so it will totally screw up the sensors and cooling stats. Find out what it has first and post back up your findings. Oh, and to verify by looking which you have you will need to look at the crank.

http://en.wikipedia.org/wiki/Chevrolet_Small-Block_engine

Doesn't matter if its one or 2 piece rear main, its the heads that were after. Also, cam lift and duration plays a big role in the FI's proper operation.

Also, truck old school small blocks are all regular flow cooling systems, bottom to top.

[88_pacifica]

Doesn't matter if its one or 2 piece rear main, its the heads that were after. Also, cam lift and duration plays a big role in the FI's proper operation.

Also, truck old school small blocks are all regular flow cooling systems, bottom to top.

Correct, but I was assuming that nobody knew the source of the "replacement motor." What if it's from an 80's Caprice?

[turbovanman²]

Correct, but I was assuming that nobody knew the source of the "replacement motor." What if it's from an 80's Caprice?

It could be but if its got the right heads, its fine, ;)

[DeckSetter]

Correct, but I was assuming that nobody knew the source of the "replacement motor." What if it's from an 80's Caprice?

Correct, no idea what the replacement motor is from.

The owner bought a timing chain cover from Napa, they gave him the wrong one. He ended up getting one from the dealer, they matched the numbers off the block up to the correct cover.

It sounds like it would be wayyy too much hassle with switching the computers and possibly wiring harnesses over anyway. I'll talk to the guy tomorrow and tell him the info.

Thanks guys!

[jre97]

The heads were changed in 87 and they went to the one piece rear main in 86. You can pick up a brand new holley or edelbrock with an electric choke for about $300. You will probably need a carb adapter plate for the intake if it's not already a square bore.