Mpfi...from junkyard? (stock)

[broncoman6524]

ok i know that mpfi came on some camaros (z28?) and all corvettes, are there anymore im missing? So if i was to walk into a yard and ask about htem what prices should i be looking for? 4-500ish?

and if i pull it all, i would need hte intake, rails,injectors, throttle body, dizzy?, all wiring and the computer correct?

IF anyone has done somehting similiar PLEASE let me know. fuel economy is killing me plus im begining to want to wander over to the "dark side" LOL.

If it matters its an 84 k5 with a 350. how much of a bitch will it be to wire this up?

 

[Ryan B.]

TPI... thats old news.

If you are a member of ck5 i did an entire write up of a tpi swap in the advanced previews/tech section.

 

[dyeager535]

There are a few of us that have/are doing the swap.

Mines essentially done, but that's not saying much.

You might as well prepare to strip the car...anything connected to the wiring you need to take essentially. Anything '89(I think) and later will have VATS, which means you won't even be able to START the engine until you burn a chip to disable it.

Of course, '85-89 are all MAF cars, not desirable compared to the 90-92 MAP's IMO. '85 is worthless, do NOT waste time on that setup. Corvette and Camaro routed some of the stuff differently, Camaro is an easier swap into the trucks IIRC.

Anymore, I don't think $4-500 is worth it. Maybe $300 or so, bit more if you can hear it run before disassembly.

 

[Russell]

Mine is basically done as well

Do your homework before you leap in. Know exactly what needs to be down, and know exactly how you are going to do it before you even buy one small part.

Also, do yourself a favour, and buy a complete, running parts car. Nothing nickles and dimes you quite like an incomplete TPI setup does.

As far as the engine goes, do yourself a favour, and install an aftermarket, fuel injection friendly camshaft, and consider a set of TBI swirlport heads. The MAP intake will bolt straight up to them, and they are well suited to the raw torque theme that TPI represents. Get a cam that makes power from idle though 5000 rpm. You won't get any more rpms out of your engine, mine is built to fit the bill, and I'm able to squeeze about 4700 out of it before it falls flat on it's face. Lumpy is NOT good, you want something that idles very smoothly.

If you want a mean, high revving, loping, fire breathing small block, and EFI, look aftermarket, cause you won't find a stock EFI system capable of handling an engine like that.

Electrically speaking, the swap isn't too difficult, esspecially if you can find an 87 TBI wiring harness to swap into your truck, then modify for TPI use. Then all your fuses will be found in the factory fuse block, you'll have the ALDL cable, check engine light, fuel pump relay / wire to the tank etc. The 87 harness should tango just fine with your 84 steering column etc.

Again, do your homework, and find out everything that is involved. If you've got questions, feel totally free to ask, and one of us will likely be able to help. The only stupid question around here, is the one that goes un-asked!

 

[merace19]

You can get around the vats if you use the switch and key from the donor car. I have Just read that MAF or Mass air flow will allow you to upgrade you motor and still work. It uses the messured amount of air to calibrate the fuel. I read this in a EFI book dealing with swaps. "MAF type of system might be better suited to people who want to modify their engines, because any increase in the airflow, caused by a new cam bigger exhaust ec... will automatically create additional fuel. But to get the optimum timing and such you still may have to get a chip burned" MAF was from 1985-1989.

 

[merace19]

Avoid the 85 TPI system as it is not like the other years and not easy to swap. Engine is same but the EFI is different.

 

[merace19]

Ryan B.
Just read all your old post. Good reading. I have actively looked and read everything on EFI that i can. Hard to understand without it in front of me.

 

[Russell]

Only problem with a MAF system is that the MAF itself is a real bottleneck, esspecially on a 400, and on an engine that is bounced around a fair bit, and possibly exposed to wet, or excessively dirty conditions, that MAF won't last very long.

Speed Density is also far more adjustable in the chip, and once tuned up properly, runs more efficiently.

So yeah, while MAF does allow for a 5 - 10% change in airflow without worrying about chip changes, it still will require tuning for any significant changes in engine dynamics, and can be a bit less reliable on an off-road rig.

 

[merace19]

Only problem with a MAF system is that the MAF itself is a real bottleneck, esspecially on a 400, and on an engine that is bounced around a fair bit, and possibly exposed to wet, or excessively dirty conditions, that MAF won't last very long.

Speed Density is also far more adjustable in the chip, and once tuned up properly, runs more efficiently.

So yeah, while MAF does allow for a 5 - 10% change in airflow without worrying about chip changes, it still will require tuning for any significant changes in engine dynamics, and can be a bit less reliable on an off-road rig.

Good points. But the MAF sensor is after the air cleaner so if you get water on your MAF sensor you gonna have Other problems. Dirt same deal. Good oiless filter and all should be ok. I just hate having to mess with the chip unless the motor has been hopped up a good bit.