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Fuel injection

hammermachine

hammermachine

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After wheelin last weekend it became obvious that I need to upgrade from a carb to some kind of fuel injection. It's also obvious I don't have the skills to install a system in my 85 K5. I could probally get one of the mechanics from my club to install it. I was looking at the Holley Pro-jection. Does anybody have any feedback about this system, or have any other options?
 
My opinion on ANY of those systems is just go stock. It's a bolt in, and relatively cheap.
 
Just find an '87-91 K5 being parted, and take every single injection piece off of it.

Best if you can hear it run, as you at least know it works and if it doesn't work after install, it's a problem with the installer. :)
 
Yep if you can find a running vehicle with TBI just swap the whole thing over. I used a 93 suburban as my donor. I did put in a new harness, computer, oxy sensor, prom etc. Or I should say I had that stuff put in. I did the motor swap with a mechanic friend and he played with all the wiring crap. Howell was very good to work with, great techs. I now get 15 mpg and starts every time quickly and no bogging.
 
Yep, and for his '85, he can "simply" swap the entire '87-91 wiring harness to include fuse panel. I assume anything '92+ (new body style of course) the fuse panels aren't a bolt in deal, so not as ideal for swapping into an '85 if so.

It's all up to the individual, but starting with one that bolts directly into the truck makes it a lot more "plug and play".
 
Tbi

So I guess I should only be looking for TBi systems from a 87 to 91 v8 vehicle. There's a ton of dirt cheap mini blazers and s 10's that I could get, but I don't know if the TBI set up would work on my K5. The other option is to keep look or save up and order a new one online.
 
If you have a v8/5.7, then just check the ECM sticker for the code "7747" at the end of the model code. If that's right, you know it's setup for a 5.7.
 
bp71k5 said:
If you have a v8/5.7, then just check the ECM sticker for the code "7747" at the end of the model code. If that's right, you know it's setup for a 5.7.
Click to expand...

That is not true. "7747" ECM's are used in many different vehicles including other than V/8 engines. The "chip" inside the ECM is what will be different if it came from a 4 banger, V/6 or a V/8. So just because the ECM is a 7747 doesn't mean the chip inside is correct for his application.
 
hammermachine said:
So I guess I should only be looking for TBi systems from a 87 to 91 v8 vehicle. There's a ton of dirt cheap mini blazers and s 10's that I could get, but I don't know if the TBI set up would work on my K5. The other option is to keep look or save up and order a new one online.
Click to expand...

You want it out of the R/V trucks only. That's the old body style up to 1991.

The S-10 stuff MIGHT work, as the fuse panels look the same to me, but the 87-91 R/V stuff is bolt in, so much better in those regards. The S-10 stuff may be too short or too long (depending on how things were run) and the injectors are probably too small. It's just better/easier to get one that is setup for your specific displacement engine, if not so far from stock that the stock EFI components can't feed it.
 
The "chip" inside the ECM is what will be different if it came from a 4 banger, V/6 or a V/8. So just because the ECM is a 7747 doesn't mean the chip inside is correct for his application.
Click to expand...

Ah, I did not realize that. Are there ECM\chip combo's other than 7747 that will work in a V/8? Or does the 7747 at least narrow down the choice? (i.e. find another donor if it doesn't say "7747"?)
 
'7747 is a "generic" ECM, as are most of the ones GM used. Probably to be found in a bunch of GM vehicles, most/all probably TBI...S10's, cars, etc. '165 would be a common ECM used on TPI vehicles, V8 and V6.

There are so many "chips" (PROM's) that were used however, it's almost unfathomable. EVERY single drivetrain combination out there had a different PROM. Say you're dealing with a 1991 K5 (for instance). Since that could be had with 465 or 700, you've got two PROM's right there. Then couple that with two different rear axle ratio combos with either transmission. Then multiply that with CA emissions and Federal emissions. Then AC and no AC. As you can see the "options", all of which changed the PROM calibration, mean literally hundreds of PROMs. This is why manufacturers now tend towards "standardized" drivetrains and option packages (see GM dropping manual transmissions in trucks, tuning being just one issue deciding that I'm sure), as it reduces the R&D and EPA testing required, as each combination/PROM has to be certified before being "legal" for sale.

With that said, in reality, few of the differences actually mean anything to the swapper. They will certainly affect how fuel is consumed and how well it runs, but compared to say a tire or axle ratio change, will be relatively unnoticed. Auto vs. manual would be a big one, whereas the difference in a PROM for 3.08 to 3.42 would be miniscule. (and even then auto vs. manual tends to run ok when swapped)
 
There's a ton of other ECM that are the same as the 1227747. But if your useing it in a V8 get one from a V8. Not only are there chip differances there is another chip in the ECM called a Netres chip which has the Limp home info. So a V6 ECM needs two chips for a V8.

Also I think the 90-91 Blazer ECM number is 16136965. The ECM is identical to 1227747. Take a look at this site for an idea of how many differant numbers there are for a C3 ECM with 2732 chip.
http://www.cruzers.com/~ludis/c3xref.html
 
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