TPI & EFI for a Gen 1 Engine

The more I read, the more I'm confused.:bonkers: This is not hard to believe coming from me.:lol::lol: Will some one explain to me the difference installing these sytems. One of the systems fits, the other has to be modified to match the heads. One system has to have holes machined for the distributer. What is the easiest install on an 82 engine, without having to rework the heads or intake.

This would make a good sticky if someone has doumented everything. I did read the sticky that GrumpVette did.

I think a TPI system is a bolt on for an 82 engine, the LT1 may be the one that requires the distibutor machine work.

Why would you need to drill a hole for this dizzy ? Is this a 92+ intake ?

I'm just asking questions trying to understand the difference. I am not sure what the difference is between the TPI or LT1. I'm just fed up with the lack of options for the CFI. I think it's time for a change. Just want to make the right choice.

Thanks

Dirtbuster1 said:

I'm just asking questions trying to understand the difference. I am not sure what the difference is between the TPI or LT1. I'm just fed up with the lack of options for the CFI. I think it's time for a change. Just want to make the right choice.

Thanks

Click to expand...

Herb, Sorry I am so confusing.....but I have had a TPI on my basically stock L48 that came with my car, then 3 years later bought a engine down here in Florida that upped the HP by 100 or so....
then went to the LT1 induction for some other whatever HP....

the TPI is a mechanical direct bolt on, it will fit and work without any crazy work, about as close to a bolt on as you can get.....

hell, I went from a Qjet to TPI within about 6 months of owning the car....

only reason it was that long was other things need URGENT attention....

I drive MY car every damn day....in the rain, through mud puddles, and even flooded out the floorboards the other day, call me the vette equivalent of iron butt for Harley drivers....


:crutches::crutches:

Gene,

I am getting a better understanding with the more I read. If I can't see or feel the parts, it's kind of hard to comprehend. I guess there is a difference in some of the motors that GM built for different year models. That is the confusing part for me. This will be a major swap for me with no one to look over my shoulder. I guess you could say I'm old school when it comes to engines. When you start adding all of the ECM's, sensors, & fuel injection it's kind of greek to me.:smash::smash:

Dirtbuster1 said:

Gene,

I am getting a better understanding with the more I read. If I can't see or feel the parts, it's kind of hard to comprehend. I guess there is a difference in some of the motors that GM built for different year models. That is the confusing part for me. This will be a major swap for me with no one to look over my shoulder. I guess you could say I'm old school when it comes to engines. When you start adding all of the ECM's, sensors, & fuel injection it's kind of greek to me.:smash::smash:

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Eh, no sweat, the basics are very simple, really all the puter does is sense the engine temp, so that is the basic choke function as to how much fuel to add....now the idle air flow through those pesky motors actually bypasses the throttle blades, which are always the same position....so that means the speed of the engine at idle, and maybe also during operation/driving air is added or subtracted to help with proper fuel management, or maintaining idle speed....as you know....pulling a vac line increases the idle speed, but also leans out the mix....and also messes up dispersion through the runners....

the Incoming air temp is bacically the same sensor as water temp....but incoming air, and so it's sending a signal in the same region it's mainly a trim function to fine tune the computer....kinda like what the O2 sensor does, tell the computer we are too rich or lean....making the thing a closed loop system....but the O2 sensor has to be 600f or more to work properly, which is why they use built in heaters to get that temp up there quicker, or at ALL if it's in a header collector.....obviously the computer need know where you pressing the throttle opening to....between zero/idle position and full open at 90*....WOT.....but there is obviously a load differance between just goosing the throttle at a stoplight and a WOT take off.....one the MAP...or Mani Absolute Pressure sensor senses the vacuum in the intake plenum...I call it the suck sensor.....so at max suck it requires less fuel on account of it's a vacuum in there and so to keep the air volume to fuel ratio the same...less fuel......so if we decide to floor it on take off, it senses less vacuum and says add more fuel.....

thems the basics of what you looking at.....more systems use a MAF sensor which senses over a heated wire, the airflow speed by it cooling the heated wire and lowering it's resistance....kinda like trying to cool a lightbulb...which is why they burn out when first turned on....less resistance, more voltage more power and the filament gives it up when old.....

Hang loose man we make a EE and a ET outta you yet.....:bump::bump::hunter:

Basically for a Gen I you have to stay with a tpi or some of the aftermarket equivalents or a EFi system based on a carb manifold. There are some more exotic ones, but my guess is that you want to keep it simple, so going the tpi route will be the best bang for the buck

Keep in mind there are 2 different TPI systems. The one you need is the early (85 - 87 I think) that has the angle center bolt holes on the intake. The later year lower intakes have the 4 center bolts (2 on each side) that go straight up and down and not at a angle like standard small block heads. You can use the later intake however you will need to have the bolt holes machined to fit your heads.

The LT-1 intake will need to have a hole cut for the dist and the intake bolt holes will have to be relocated. You will also need to relocate the t-stat housing due to the LT-1 intake does not have one, they sell this piece (see photo below). You will also have to buy a diffrent throttle cable bracket and adapt the fuel lines that exit out the rear on the LT intake. There are places that are doing the machining on the intake for around $150 bucks.



I was going to go this route until I was able to get a good deal on a super ram and went that route.

If you decide to go TPI I have the old one off my car (lower and upper intake and runners) that would bolt right on your motor. You would still need TB, fuel rails and injectors.

Phil

If you stick with the maf sensor it will probably work on your engine, but from 89 up (i believe) they went with map, which could need reprogramming.

I was going to go this route until I was able to get a good deal on a super ram and went that route.

If you decide to go TPI I have the old one off my car (lower and upper intake and runners) that would bolt right on your motor. You would still need TB, fuel rails and injectors.

Phil[/QUOTE]

I have extra rails and regulators, etc for a TPI.....

Gene,

Can you measure your TPI unit it for me. I have to have something that is 8" from one of the intake bolts,to the top of the fender. If it will work I might stop by and get it while passing through the week of the 13th. I have taken all I can of this CFI. What are the parameters for the TPI. If I can't get my O2 any hotter, it still might not work. The easiest thing to do might be to reinstall my stock exhaust to fix that.

Thanks

Herb

Dirtbuster1 said:

Gene,

Can you measure your TPI unit it for me. I have to have something that is 8" from one of the intake bolts,to the top of the fender. If it will work I might stop by and get it while passing through the week of the 13th. I have taken all I can of this CFI. What are the parameters for the TPI. If I can't get my O2 any hotter, it still might not work. The easiest thing to do might be to reinstall my stock exhaust to fix that.

Thanks

Herb

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OH, hell, we leaving in the Am on the 13th to go to Satellite Beach for 3-4 daze with some friends...be back by wed or thurs mid afternoonish....

maybe later in the week, that O2 I used runs hot enough all the time, and it's fine....dunno why yours won't, makes no sense....you sure you getting full power through that thing?? that coild takes maybe 2 amps, and I question the connections....otherwise it makes no sense.....how many wire that sensor have???

Mine has 3 wires, the early ones like stock for your car are ONE wire....some of the later ones are 4 wire with the O2 sensor (not heater) ground being run back to the computer directly.....

:crap:

Gene,

I will be coming back threw on Friday after the cruise. The new O2 works ok in the 1 wire mode. When I hook up the heater it jumps back to around .85 to .9V. Then the ECM seems to get all of the data jumping around, hunting back and fourth. I don't want to mess up another O2 until we fiqure out whats going on.

In my best guess, the ECM doesn't look at to many things while in open loop. I say this because the BLM & the INT stay fixed at 128. The O2 voltage data is logged ok, along with the IAC counts & the CTS data. I'm not sure where the ECM variables have to be to go into closed loop, but the O2 voltage must have to be above .55V, & the CTS probably above 150F or so. But when the O2 is heated, it will jump into closed loop no matter where the CTS temp is?

Gene,

I will be coming back threw on Friday after the cruise. The new O2 works ok in the 1 wire mode. When I hook up the heater it jumps back to around .85 to .9V. Then the ECM seems to get all of the data jumping around, hunting back and fourth. I don't want to mess up another O2 until we fiqure out whats going on.

In my best guess, the ECM doesn't look at to many things while in open loop. I say this because the BLM & the INT stay fixed at 128. The O2 voltage data is logged ok, along with the IAC counts & the CTS data. I'm not sure where the ECM variables have to be to go into closed loop, but the O2 voltage must have to be above .55V, & the CTS probably above 150F or so. But when the O2 is heated, it will jump into closed loop no matter where the CTS temp is?

Dirtbuster1 said:

Gene,

I will be coming back threw on Friday after the cruise. The new O2 works ok in the 1 wire mode. When I hook up the heater it jumps back to around .85 to .9V. Then the ECM seems to get all of the data jumping around, hunting back and fourth. I don't want to mess up another O2 until we fiqure out whats going on.

In my best guess, the ECM doesn't look at to many things while in open loop. I say this because the BLM & the INT stay fixed at 128. The O2 voltage data is logged ok, along with the IAC counts & the CTS data. I'm not sure where the ECM variables have to be to go into closed loop, but the O2 voltage must have to be above .55V, & the CTS probably above 150F or so. But when the O2 is heated, it will jump into closed loop no matter where the CTS temp is?

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Herb, Friday is cool, good show....you having your vette with you?? would be nice to see it in the AM if possible, as my house faced directly west and so the sunlight comes in the garage pretty brutal....:shocking:

The O2 readings are supposed to go from .1 to .9 volts back and forth at say idle...or steady cruise....you can see that on a scanner or with a DVM, which is what I always used before I got a scanner some years ago....there is a steady on conversation between the O2 and the computer controlling the injector pulse width (ON time).......so it is normal for that voltage to sway around within the parameters above.....the fact you heating it up will make it react sooner, that's all, wether the computer is ready or not....which depends on the water temp....

the BLM I THINK will stay until the engine warms up enough, even though the O2 is changing with driving.......the temp it goes closed loop at can be changed and I had mine lowered with a chip....

how far away are you?? time/distance?? from say Jax, as I'm about 17 miles SW of the city center, crow flight....:hi:

Gene,

I think we are going to drive down the wifes car for the cruise. I wouldn't trust the 82 with all that is going on. I will be putting the 04 in the shop before we leave, for repairs on the door. On Friday the 17th we will be headed back from Port Canaveral probably leaving around 10am, maybe sooner? Sound like you are somewhere between Jax and St Augustine.

Herb

Herb

I am on the opposite side of the St. Johns river from St. Augy's....

head north, take I 295 north/west for about 6 miles, cross my favorite 3.5 mile long bridge....over the St. Johns....and go another 4 miles to Blanding blvd....within 2 miles of the place....south like heading to middleburg....

simple to reach really....

:beer:

If you have additional questions on changing carburetor to TPI give me a shout through the forum.

I am running TPI on my 63 and it is not really difficult. You can obtain a "stand alone" TPI harness from several sources. With that harness, a computer and the addition of a high pressure electric fuel pump you are just about there.

Rich:beer:

badbirdcage said:

If you have additional questions on changing carburetor to TPI give me a shout through the forum.

I am running TPI on my 63 and it is not really difficult. You can obtain a "stand alone" TPI harness from several sources. With that harness, a computer and the addition of a high pressure electric fuel pump you are just about there.

Rich:beer:

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Thanks for the reply. I decided to go with a LS1 motor. I got a good deal on it. Now the neck is getting in the way again. Looks like I will put things off until after surgery.