Here's a few tips from putting TPI in my '71 Chevelle:

I used the ignition feed from the old distributor to feed the ecu and coil. Doesn't work. It's a resistor wire. There is a bypass during cranking. So the car would crank and catch OK, but as soon as I released the key it would die. So I used this wire to work a relay, and fed the coil and ECU from that.

Now the car started, but would not turn off when I shut off the key. The gen light on the dash feeds back just enough current through it to keep the relay energized. This was solved by putting a 10w diode in line with the bulb. To make sure the diode is going the right way, turn on the key without starting the car. The light should come on. If not, turn the diode around.

The stock charging system does not cut it with all the extra electrical load. After about a week the battery had drained to the point that the car would not start. I upgraded to a 105 amp CS alternator. Instructions are here: http://www.chevelles.com/techref/ftecref14.html

The heater hoses are routed differently. On the TPI cars, the heater return goes to the radiator. On Older cars, it goes to the water pump. The water pump hose is right in the way, and interferes with other hoses and the new K&N air cleaner on the throttle body. Here's how I routed the hoses: From the inlet of the heater to the throttle body warmer - no change. From the manifold to the throttle body, I moved the connection at the manifold end to the opening where the cold start themostat was supposed to go, and plugged the old opening. The hose was lengthened and routed around the heater return hose. For the heater return hose, I used an angled connection to point it out of the way. Not sure where you can get an angled connector. I just got lucky an had one off an old Packard. The alternator bracket had to be cut to make room for the hose.

The new manifold needs to be modified to fit the old heads. The four bolt holes in the middle need to be drilled out at a new angle, and you will need 17deg angle washers to put under the bold heads. This sounds easy, but it took me a couple of hours to do.

Cheap things you should replace:
-The o2 sensor I had lasted only 1 week.
-Heater hoses.New ones don't rupture.


Saving money:
-I used the harness from a V6 and modified it. This is not for the faint hearted. It's more like making a whole new harness using the old wire and connectors. You need to get two of the CTS connectors, because the V6 uses a different type of MAT sensor.
-When you get the ECU from the junkyard, make sure you get the mounting bracket and brackets for the MAP sensor and relays.


Other tips:

-Painless wiring makes as VSS sensor that connects between the trans and spedo cable. Works great.
-You will need some programming. Some things that may be different from the TPI car:
-VATS - you need to disable
-EGR - on the old engine, it does not use the computer
-AIR - does the old engine have it?
-VE - probably needs adjusting if you are using your old engine
-Canister purge.
Of these, only VATS is a show stopper. The others will just set codes and make it run like crap.
-K&N makes an air cleaner just for this conversion. Attaches to the front of the TB. Later on you may want to install a cold air intake.

Bottom line, It's running great now, and gets better every time I adjust the tuning tables. I found I needed more timing, especially at the low end. For VE, I needed less at low RPMs and more at high.

 

I forgot a couple:

You will need to install new fuel lines and a fuel pump. This is the part of my conversion that took the longest. I thought I would use the old line, and run a hose for the return. But the old line, being old, couldn't handle the pressure and leaked. I ended up installing two new steel lines. NAPA sells the steel tubing in 25' rolls. One roll was enough. I used hose clamps to connect the hoses. I used a brake line flaring tool to flare the ends of the tubing so the hose could not come off.

Install a surge tank. I did not do this because It seemed like a lot of work, and I have not figured out how yet. With a full tank of gas, everything is fine. As the gas get below 1/2, I start to get a miss when I hit the gas. The gas in the tank sloshes backward and the fuel pump starves.

 

Yeah, isn't TPI swapping fun!? I did it in my 71 Camaro about five years ago. I experienced several of the things you mention below except I went with a 1986 manifold which had the old style bolt holes and an SLP swap harness which was basically stock harness with all of the connections. I also went with all new sensors since I didn't want to chase down problems after I installed it.

From there it's been one modification after another to get more power!!! But I think I've found my stopping point.

 

yeah definitely a learning experience,but worth it in the end.

 

I installed a SD unit on my Vet 3 years ago. Had to replace the fuel pump about a year ago. Otherwise, Shazam, one bad mothervet (with a few extras of course)

 

Actually, what I did was to have my tank modified to include a baffle tray for the pump to sit in. I then found a third gen fuel sending unit and put a high-flow pump on it. It fit right into my tank with no modifications (except for slight bending to prevent bottoming out)! Even the gas gauge works properly!

 

Hey, nitro,

Did you ever find what was causing your idle misfire? Still struggling with mine.

Thanks

 

hey protour,no and its starting to get on my nerves,ive swapped the gear ,rechecked for vacuum leaks,replaced tps set that a hundred times,cleaned iac,and reset that(might buy new one this week)i did check wires and found one that wasnt reading right but when i checked it again it was,so im thinking a break in the wire when i move it around,thre not that old and there accel 300+ wires race wire.I have a deal lined up on a 96 lt-1 so might swap that in it if i cant get anywhere.its shame cause it runs incredible after i leave off idle.

 

I feel your pain, man!

Actually, I'm going to get a used laptop from my buddy to use with my new Romulator. I'll try to tune out the misfire as best I can and just run it like that until perhaps one day when I stumble accross the problem.

Good luck on yours.