Where is the fuel injector on a GM TBI?

The GM TBI (Throttle Body Injection) system uses a pair of low pressure fuel injectors mounted above the throttle body opening. Unlike a port fuel injection system, that sprays fuel into the intake manifold runner just above the intake valve, the injectors in this system spray fuel directly into…

Why is my Check Engine light on after installing fuel injection?

Most of the problems encountered while installing your fuel injection system or after a time of operation are very simple. If your check engine light is on you more than likely have a hard fault meaning something is grounded out, unplugged, operating out of range or has gone bad.

Can a bad fuel pump start a GM Spider?

If you need to test the ‘spider’ equipped GM pickups or SUVs, the following tutorial will help: Troubleshooting The Fuel Pump (GM 4.3L, 5.0L, 5.7L). A bad fuel pump will make your 4.3L, 5.0L, or 5.7L throttle body fuel injected pickup or SUV crank but not start. Here are some more specific symptoms:

What causes a fuel injection system to leak?

First and foremost the engine and fuel injection system must be free from vacuum leaks. Vacuum leaks are the leading cause of installation issues with your fuel injection system. Check all sources of potential vacuum leaks including components not related to the fuel injection

Do you need a tachometer for fuel injection?

Use of this section may require a digital voltmeter, test light, fuel pressure gauge, timing light, tachometer and/or a diagnostic scan tool. If you are familiar with vehicles and how they are serviced you should be able to work through this section with no issues.

What should the fuel pressure be on a 350 TBI?

From 370-440hp you need to bump the fuel pressure up on the 454 injectors to the 15-18psi to increase their flow rate to 100lb/hr.

Can you change the throttle body on a 350 TBI?

Modify the throttle body. This one pretty cheap but does require removing the throttle body. UTIMATE MODS . Stock 42mm TBI units flow around 450cfm which if you look at http://www.carburetion.com/calc.asp a stock 350 even with a cam upgrade to increase the powerband to 5500 rpms isn’t going to use much if any more than that stock throttle body.

What is the TBI code on a 1990 Chevy truck?

Consult a service manual or see below for any check engine light code definitions. You can use a late 80’s or early 90’s GM TBI definition. If you have access to a scan tool use a hook up for a 1990 350 cu. in. 5.7L Chevrolet truck. For some scan tools enter VIN 10th“L” 3rd“C” 8th“K”.

What kind of fuel pump does a TBI 454 have?

Stock TBI 454 makes 230hp and 380tq so stock fuel pump is maxed out right off and a typical 454 will run better with a fuel pump upgrade even with stock chip. GAS MILEAGE. Always a big complaint with 454 TBI trucks. 90 and older is particularly bad and that is largely due to NO OVERDRIVE.

What kind of injectors are in a TBI?

Each remanufactured TBI Assembly includes Injectors, TPS, Idle Air Valve, and Bushed Throttle Body Housing. Most TBI’s are “In Stock”and ready for Quick Delivery. We also stock General Motors Rebushed Throttle Body Housings and have an inventory of Multi Port Injectors.

How does the GM TBI fuel injection system work?

Can a carburetor be replaced in a TBI engine?

While it works fine for stock applications, the fact is that General Motors’ Throttle Body Injection (TBI) system is a nightmare for modified engines. Though it is possible to replace the injectors and throttle body, and to reprogram the computer, many find it simpler to “down-grade” to a carburetor setup.

What happens to the fuel injector in a Chevy?

The fuel injector in a Chevy is responsible for metering the fuel that enters the intake manifold, and ultimately the engine. If your fuel injectors are dirty or are leaking, you’ll notice decreased performance, increased fuel consumption, and your engine may not run at all in extreme cases.

How does idle air control work in a GM TBI?

The air gap between the throttle body and the throttle plate is calibrated to allow enough air to pass by it for the engine to run at base idle speed. The IAC (Idle Air Control) valve utilizes the on-board computer to fine tune the idle speed according to engine conditions.

Where is the idle plug on a GM TBI?

Plug the vacuum lines with golf tees or other suitable item. Remove plug over the idle screw located on the right front of the throttle body by using a hammer to drive a punch into the plug and then using the punch to pry the plug out of the throttle body.

Why is my fuel injection system plugged in?

The electric fuel pump installed for a fuel injection system will draw considerable more volume of fuel from your tank than your old system did. If there are any contaminants in the tank this many times will plug up or greatly restrict the flow of fuel to the system causing many issues. Step by Step Troubleshooting guide.

What was the compression ratio of a 1995 Chevy 350?

Low Compression The low-compression version of the 1995 Chevrolet 350 was used in four vehicles: Suburban, G30 van, C/K3500 and C/K2500. It had a cylinder bore of 4 inches, a piston stroke of 3.48 inches and an 8.3:1 compression ratio. This engine produced 180 horsepower and 295 foot-pounds of torque.

How to reset the baseline idle speed in a GM TBI?

Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench. Reconnect the IAC valve. Reinstall the air cleaner and remove the paper clip from the ALDL connector. Reconnect the battery terminal after 5 minutes and test drive the vehicle.

How much horsepower does a 350hp TBI engine have?

A 180hp 350 tbi motor makes a good 230-240hp using Sae gross math. Very few places advertise Sae net numbers.

What are the facts about a 1990 Chevy Suburban?

This page is dedicated to facts, specifications and statistics specific to the 1990 Suburbans only. Much of the information applies to 1989-91 Suburbans as well as there are very little changes within the last 3 years of the 7th generation. To cover all the years of the Suburban starting from 1935 would be a major undertaking.

How to fix a 1990 Chevy 5.7L TBI fuel problem?

It ran long enough to drive up on the trailer while under its own power and it also drove off the trailer on its own power (not that same day I brought home) but you did have to keep foot on throttle otherwise it would stall out and not start again until the next day. 1. New Fuel pump 2. New Fuel filter 3. New Fuel pump relay 4.

How many spline did a Chevy Suburban have?

With a T400 or 4L80E trans or 5 speed, it will be 32 spline. There was only 1 available transfer case in 1990, the NP241C.

When did GM stop making the Chevy Suburban?

On August 31, 1991, production of the large SUVs was moved to Janesville Assembly in Wisconsin. GM ceased production of GM vehicles in December 2008. It was the oldest operating GM plant.

What is the TBI Chevy 5.7 valve adjustment procedure?

Adjust the exhaust valves of cylinder No. 2, 5, 6 and 7 and the intake valves of cylinders No. 3, 4, 6 and 8 by performing the following procedures: Back out the adjusting nut until lash can be felt at the pushrod. While rotating the pushrod, turn the adjusting nut inward until all the lash is removed.

How to set valves and injectors cat 3116 diesel engine?

The timing specification is on the valve cover and the dial indicator has to be calibrated before checking injector timing. Rotate Engine 360 degrees to #6 compression stroke. As I stated before the valves can be adjusted with basic tools but the other procedures need to be performed with the CAT tune up kit.

Where is the EGR valve on a 1994 Chevy?

This will ensure that the components are cool and prevent potential burns. Open the hood of the vehicle and locate the EGR valve. The EGR valve on a 1994 Chevy is on the lower intake manifold beside the throttle body. The EGR valve is a circular metal component with a vacuum hose coming off of it.

What causes a vacuum leak in a fuel injection system?

Vacuum leaks are the leading cause of installation issues with your fuel injection system. Check all sources of potential vacuum leaks including components not related to the fuel injection system. There are instances where the vacuum leak is coming from the adapter plate used to attach the throttle body to the manifold.

What’s the difference between’93 and’94 TBI 454 engines via injectors?

However the above post also indicated that those trucks had 30 psi or so injectors. I searched another sight and got that the injectors on the 94-95 454 trucks were in the 30 psi range but however the injectors are 46# injectors instead of the 90# on 3500 heavy duty 454 trucks like mine ’93 dually.

Is the throttle body fuel injection a carburetor?

For the Last Time, Throttle-Body Fuel Injection Isn’t a Carburetor! – Autotrader For the Last Time, Throttle-Body Fuel Injection Isn’t a Carburetor! Instead of digging up some obscure bit of automotive history, today I’m going to talk about one of my pet peeves: Confusion between carburetors and throttle-body fuel injection, otherwise known as TBI.

Where is the diagnostic connector on a GM TBI?

Unfold a paper clip and bend it into a “U” shape. Push the ends of the paper clip into the “A” and “B” terminals of the ALDL (Assembly Line Diagnostic Link) connector, also called the diagnostic connector. In GM vehicles that use this TBI injection, the connector is a black plastic rectangular connector located under the driver side of the dash.

What kind of TBI is used for throttle body injection?

2. Throttle Body Injection = TBI The 4.3, 5.0 and 5.7 TBI’s are all the same CFM with 1 11/16th bores. The injectors are different sizes. The 454 is larger with close to 2 inch bores. It is recommended a TBI from about the same size engine to be used in your conversion or larger for high performance built engines. 3. TBI Wiring Harness.

What kind of EFI system do I need for a TBI engine?

TBI Fuel Injection Conversion using a GM TBI EFI system! One of the most popular EFI conversions to older Chevy engines or any engine for that matter is the GM TBI system using the 1227747 ECM.

What should the idle speed be on a GM TBI?

Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier. Turn the screw to adjust the idle speed to 650 RPM +/- 50 RPM. Turn off the engine and disconnect the negative battery terminal from the battery using a wrench.

What causes PCM to disable fuel injectors?

@jrt2020 , Josh, The anti-theft system (Pass Lock) failure will mimic this, as anti theft tells PCM to disable the fuel injectors.

Where is the fuel injector on a GM TBI?