About this tech support page

This tech support page is based on our 30 plus years of experience doing performance work and custom installs. Please let our experience help you with your project. More than likely if you think you have a problem, we already have an answer for you, if not we will learn!  So please take the time to contact us for assistance, before you assume it is a problem. We may be able to save you time, grief and money!

It is important to know that you will need comprehensive mechanical abilities, knowledge and above average tools to complete the install of this system. More than likely there will be modifications required to fuel lines and such. Again, we are here to help the best we can, so feel free to contact us before and during your project install.

Download FIRST Tpi Installation Manual/ Fast manuals here

PLEASE NOTE:  The Fast EZ manuals have a picture of a throttle body type efi, but the intructions are the same for the FIRST TPI.

Helpful Tech tips and information

Early style throttle body mounting

The early style plenum required a steel diversion plate to seal off the EGR port properly. It was common for these to be removed because customers did not understand why it was there. If this plate is missing, just give us a call we have them for sale. 

Steel diversion plate

This plate is needed to properly seal the EGR port so there is not a large vac. leak under the throttle body flange.

Diversion plate not installed

Notice the large hole that is left open under the throttle body flange when the plate is not installed. This plate is used to apply pressure for the gasket to seal.

Diversion plate installed

Now you can see how the hole is sealed off when the plate is properly installed, no more vac. leak!

Large cap HEI modification

You can use the GM large cap distributor with the FIRST® TPI, however because of the large size of the base runner you will more than likely need to remove some of the lower casting on the dist. base to allow room for adjustment.

Fuel rail layout

The FIRST® fuel rails are 6016 billet aluminum with 3/8 NPT female on each end. You can use many different combinations to make your connections. You can use hose barbs with fuel injection rated line. You can use an 3/8 NPT male to 3/8 NPT female inverted flare to use steel lines or even flare your existing steel lines. You can also adapt AN fittings to the rails. Typically we use the crossover in front for clearance reasons and use the rear exits for the main feed line and out to the fuel regulator. It is possible to use a long loop of fuel line to go around the dist. if you need to use the front for feed and return.

Fuel pump and filter layout

It is a good idea to have a pre fuel pump filter to catch debris from the tank, then the fuel pump and then another filter after the pump which will catch debris from a failing fuel pump before it gets to the fuel injectors!

Cold air intake

It is usually fairly simple and recommended to add a cold air intake set up in most applications. This really does help keep cool air going into the intake. Room can sometimes be an issue we know this,  but we have always been able to figure out a way to get it done. 4" couplers and 4" aluminum tube in this picture with the K&N filter behind the grille.

Proper return spring installation

The return spring tab should be mounted like in the picture, so that when full throttle is achieved the spring will run along side of the lever like in the picture. You should not need to move the location of the spring tab to achieve proper return pressure. If you feel it is not providing the proper return to idle pressure more than likely something else is wrong and you should contact us so we can help you figure out your situation. We do not charge to inspect throttle bodies, no matter what the age. Just cover shipping charges.

Proper TPS mounting

There should be no pressure on the TPS bracket at all, the job of the bracket is to hold the TPS so that the TPS lever on the throttle shaft can properly contact the TPS lever during rotation of the throttle shaft.  If for some reason you feel something is not correct, please contact us so that we can walk you through this situation. The part number for the "standard" brand is TH37T.

Proper TPS mounting

It is OK if the TPS touches the throttle shaft screw as they should move in time together like the late model TPS that mounts directly to the shaft. If you feel that something is not correct please contact us so that we can walk you through this situation.

Proper MAP bracket install

This is how the MAP bracket is properly mounted. Yes, you do need to hook up the vac. line to one of the 1/4 vac. fitting on the plenum!

Manifold absolute pressure (MAP) sensor

Part number for "standard" brand is AS5T. 

Intake air temp (IAT) sensor location

This is where the IAT sensor is typically mounted on the FIRST TPI. It can be mounted anywhere in the plenum area or intake tubing.

Intake air temp (IAT) or manifold air temp (MAT) sensor

Part number for "standard"  brand is AX1T

Idle air control (IAC) mounting location

This is where the IAC valve is mounted on the FIRST TPI Throttle body.

Idle air control (IAC) valve

Part number for "standard" brand is AC1T

Oxygen sensor (O2)

Coolant temp sensor

The part number for "standard" brand is TX3T

Coolant temp sensor location

This is a typical coolant sensor location on the FIRST TPI. It can be mounted anywhere in the coolant passage.

Important bolt to seal

 It is necessary to use sealant on the passenger front lower runner bolt, this does go into the front coolant passage. 

Installed Throttle cable bracket

 This is the proper way to mount the throttle cable/ Detent bracket. We have seen installs where this bracket is mounted upside down or on the forward bolts and this is totally incorrect. This bracket has been designed to be mounted like in the picture. The angles are correct for the throttle cable, cruise cable and detent cable including the 700r4 trans  which we run in many vehicles with the FIRST® TPI. If for some reason you cannot seem to get your cables to function with this bracket set up this way, please contact us so that we can work through this situation with you. 

Good tool to have

 Your install of the runners will go much easier, if you have an extended 3/16" ball end hex socket. This will allow easier positions to get the hard to reach under the plenum and lower runner bolts. 

Possible coil mounting location

You can use the machined boss on the right rear section of the base manifold to mount a small cap distributor remote ignition coil when not using the vortec heads.

FIRST TPI Dimensions


Vacuum Ports