What should fuel pressure be on a TBI fuel injection system?

Fuel Pressure is critical to the operation of a fuel injection system. Always check to insure that you have the proper fuel pressure. Fuel pressure should be a constant 10 – 15 PSI on a TBI fuel injection system and is typically around 12 – 13 psi. Higher pressure than 15 psi indicates that there is an issue with the installation.

Can a fuel pump be replaced with a TBI?

Of course, the simpler solution is to simply replace the fuel pump, which will serve the dual purposes of simplifying installation and replacing the worn fuel pump with a new unit. Though the swap is fairly straightforward, be forewarned that vehicles with the computer controlled 4L60-E automatic overdrive transmission will need additional work.

Can a 2.8 liter Chevy S10 not start?

When the ignition control module fails, your 2.8 liter Chevy S10 (GMC S15) will crank but not start. Testing the GM 7 pin ignition control module is easier than you think and you don’t even have to remove it (from the vehicle) to test it.

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”.

Which is the best S10 throttle body unit?

Chevrolet S10 Fuel Delivery∕ Chevrolet S10 Throttle Body System∕ Chevrolet S10 Throttle Body Unit Chevrolet S10 Throttle Body Unit Shop AutoZone for Chevrolet S10 Throttle Body Unit. Sort by FeaturedPrice (low to high)Price (high to low)

Why is there no fuel spray from injector?

On the way home it stopped and hasn’t run for weeks now. There is fuel and pressure at the injector but no spray. There is a red wire and blue wire there. The red has 12 volts, the blue is supposed to pulse on cranking. It does not pulse.

What’s the difference between the 88 and 92 injectors?

The Throttle bodies look the same, the injectors may have some internal difference, perhaps the 92 has higher fuel pressure, the 88 only has 9 to 13 lb fuel pressure. I’m on my way to get the noid light now, its noon here.

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.

How do you clean throttle body injectors?

Spray the injector or injectors with throttle body cleaner, and gently clean the exterior and the tip of the injector with the brush. Do not insert any metal objects into the tip of the injector, as this will enlarge the nozzle tip, permanently damaging the injector.

How does TBI work?

TBI fuel injection is a type of fuel injection system where the fuel is injected into the throttle body. The throttle body fuel injection system, or TBI as referred to by GM or CFI by Ford, works using a single or pair of injectors. The throttle looks like a carburetor without the fuel bowl, the metering jets or the float.

What is throttle body injector?

throttle-body injection. noun Automotive. a fuel-injection system in which an injector (throttle-body injector) delivers fuel to a central location within the intake manifold of the engine.

What is engine injector?

An injector is a device for introducing fuel under pressure into the combustion system of an engine. The vibration of the four-cylinder engine cracked a fuel injector pipe. Larger injectors increased fuel flow to the 2.4-liter turbocharged engine.

Is there an injector pulse while cranking the engine?

The engine will run if you either spray starting fluid down the throttle body or hook up a remote start switch. If you use the key, there is no injector pulse while cranking. As you let go of the key and return it to the run position, the injectors give one squirt.

What kind of scan tool do I need for GM TBI?

A scan tool can be used and set up for a GM TBI application to read the data, or to check for stored codes. 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.

How to troubleshoot your TBI fuel injection system?

Troubleshooting your TBI Fuel Injection System 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. See

Where does the vacuum leak come from on a TBI?

There are instances where the vacuum leak is coming from the adapter plate used to attach the throttle body to the manifold. If this is the case make sure that the seal is positive between the manifold and the adapter plate; also between the adapter plate and the throttle body.

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 causes a Chevy C / K 1500 to bog down?

My truck bogs down (and tries to die) when I give it gas to accelerate off of a stop. There is often a backfire or two when this happens. Pumping the gas does not help. I basically have to crawl through any intersection until it picks up a bit of speed from idle. The truck idles smoothly, and it runs fine once it’s above about 5-10mph or so.

What causes no fuel to pass through the carburetor?

No fuel at your carburetor can be caused by many things. It could be a simple issue like a fuel filter plugged so tight that no fuel can pass through.

Can a Chevy 350 TBI run from a carb?

Iv helped my buddy put a 383 stroker into a 01 s10 but he changed out the tranny to run from the carb and by the the way the engine is going into a 97 Chevy k1500 that had the 4.3vortec so I need help figuring out the wiring Why? Cause it’s my toy and I don’t have to pass emissions

What is the best carb and intake on a 93 Chevy c1500?

I have a few questions I’m looking to do a carb conversion on my gm goodwrench 350 tbi out of a 93 Chevy c1500 What is the best carb and intake and what to do to keep the 4l60e?

What do you need to convert a TBI to a carburetor?

The most basic things you’ll need to convert from TBI to a carburetor is a carb and a matching manifold. You could try to track down a used stock manifold, but aftermarket aluminum manifolds like the Performer RPM make more power, are lighter and will only run you about $60.

Where to spray starting fluid on GM TBI fuel system?

Spray starting fluid down the bore of the throttle body. When you have sprayed a good squirt of starting fluid, quickly place the air filter assembly’s cover back on. IMPORTANT: Placing the cover back on the air filter assembly is important because it’ll prevent any back-fire, that may occur, from spouting flames out of the throttle body.

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

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.

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.

What does 0 psi mean on fuel pump?

The fuel pressure gauge will register 0 PSI. OK, now that the testing part is done, let’s take a look at what your results mean: CASE 1: If the fuel pressure gauge registered 0 PSI. This confirms that the cause of your TBI equipped pickup’s ‘no start’ condition is caused by a lack of fuel.

Where is the fuel injection switch on a 1989 TBI truck?

Small HEI Distributor with Externally Mounted Coil or Large cap (internal coil) distributor. It must be fuel injection style with 4 wire feedback to the ECM MAP Sensor (located on passenger side of intake manifold and can be moved to the firewall) Part # SU105 Two Terminal Oil Pressure Switch for 1989 TBI Truck (Part number PS215)

What kind of fuel pump wire do you need for TBI?

The GRAY wire labeled “Fuel pump Feed+” must be connected to the positive fuel pump power wire to energize the fuel pump. A typical TBI pump pressure must be able to maintain 15 to 18 PSI. Brake Switch The PURPLE wire on the 700R4 transmission plug must be connected to the Brake Switch in your vehicle for proper Torque Converter Lockup operation.

What does 12 psi mean on GM fuel pump?

CASE 2: If the fuel pressure gauge registered 12 PSI. This fuel pressure gauge result lets you know that the fuel pump is working and delivering enough fuel to the fuel injectors. The reason your 4.3L, 5.0L, or 5.7L GM vehicle is not starting is due to another reason.

How is the throttle connected to the accelerator?

In the old days, there used to be a cable that was connected from the throttle to the accelerator. But now in the technological age, the car’s computer controls when the throttle opens and closes by the feedback it gets about the acceleration of the vehicle.

How is TPS used in a fuel injection system?

The TPS provides the most direct signal to the fuel injection system of what power demands are being made by the engine. The TPS signal is continually measured and combined many times per second with other data such as air temperature, engine RPM, air mass flow, and how quickly the throttle position changes.

How does the Chevy throttle body injectors work?

by Lee Sallings. The throttle body injection system used by Chevy was a natural progression from the carburetor previously used. Pressurized fuel is strained through screen-type filters before it is introduced into the engine through a pair of injectors located above the throttle body’s venturi and throttle plate.

Where are the fuel injectors located on a Chevy?

Pressurized fuel is strained through screen-type filters before it is introduced into the engine through a pair of injectors located above the throttle body’s venturi and throttle plate. Over time, varnish and sediment clog the screens and injectors, causing inefficient fuel atomization.

What causes hesitation and surging on Blazer 4.3L?

Fix Hesitation and surging on Blazer 4.3L If you have Hesitation and surging on Blazer 4.3L and it’s driving like a dog—poor acceleration, hesitation, or a surge and you suspect a fuel problem, you may be partially right.

Why is my Blazer 4.3L driving like a dog?

If you have Hesitation and surging on Blazer 4.3L and it’s driving like a dog—poor acceleration, hesitation, or a surge and you suspect a fuel problem, you may be partially right. But before you start replacing really expensive components like the fuel pump, try this: Disconnect the electrical connector to the MAF sensor and take it for a drive.

Where does the brake line go on a TBI fuel pump?

Steel 3/8″ brake line connects to the pump’s output and heads forward along the left hand frame member. A 3/8″ coupling joins another section of steel tubing and connects to the fuel filter. The filter used is a common GM fuel injection filter, NAPA 3481.

When to change the TBI pump in a car?

Nice thing about the Actron gauge is the hose is long enough that you can watch it while you drive. If the fuel pressure drops more than 1 psi under 8-10 seconds of full throttle the pump should be changed and dont put the stock TBI pump back in even if your engine is stock.

Where is the return line on a TBI fuel pump?

The yellow arrow shows the new return line from the regulator connecting to the old steel fuel line which was reused for returning gas to the tank. Fuel returns in the original TR6 supply line and back near the new pump, is coupled to 5/16″ plastic line with a short section of rubber hose.

Where is the test valve on a fuel injection system?

1. Locate the Schrader valve. Most modern fuel injection systems come equipped with a Schrader or test valve located on the fuel rail. The valve is similar to the air valve on your tires. 2. Connect your fuel pressure gauge to the Schrader valve or test port.

What kind of fuel injection does a Dodge truck use?

The greater efficiency of the system led engineers to drop EGR on the 1996 trucks. In 1997, the 3.9 received sequential multiple-port fuel injection, where each injector fires as the cylinder is drawing in air (in the older multiple-port injection systems, the injector often fired against a closed valve).

Where was the 3.9 V6 Dodge truck engine built?

Head of engine tuning Pete Hagenbuch remembered, “The 3.9 which was built in Mound Road, on the machining equipment which included a 90 degree bank angle. It was another one of those boom-boom, boom-boom type engines.

Why does my 1993 Chevy TBI stall at idle?

Timing is steady and not jumping all over. It is a fuel issue. The only code that ever sets is a P044, lean exhaust, and the exhaust is really lean. We have swapped PCM/PROM with a same year Suburban, no change. Both vehicles run the same as this did using the other’s PCM.

How many MV does a 1993 Chevy TBI have?

Even now it seems on the lean side, but will for a while have one 02 crosscount before the 20 second lean PCM clock expires throwing it into open loop. The 02 MV hot will frequently hang down around 56 MV to 156 MV and never cross over to rich for a long time.

What to do if your Dodge 318 won’t start?

If you have a pick-up coil then you don’t have crank position sensor. 1st check for spark at plugs during “no start”. If not ,check for spark from coil wire. If o/k then check rotor and dist cap for carbon tracking. You can’t post conmments that contain an email address.

Can a TBI be used as a return line?

These fittings are not suitable to use as a return line because they have an orifice in them and restrict the flow of fuel back to the tank. If you have installed your return line to a “vent” line you will need to route the return line in a different fashion. Fuel pressure on a TBI unit should stay constant under all throttle conditions.

Why are my diesel injectors not working properly?

Normally this causes damage to the diesel injectors. If this is not corrected, the problem will arise again. This is an expensive failure and no short cuts can be taken. For Common Rail systems that have metal damage, it is recommend that the fuel rail, fuel lines, and injectors be replaced.

How to diagnose low pressure in a diesel tank?

The best way to diagnose this is to look at the fuel supply in 3 areas. Low pressure supply from the tank to the H igh P ressure P ump (HPP) – some vehicles rely on the HPP to suck the fuel from the tank while others have an electric pump in the tank or fuel line to supply fuel to the to the HPP.

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.

How to test the fuel pump on GM TBI fuel systems?

One method involves removing the fuel filter and using an adapter, that has a Schrader valve on it, in its place. You then connect your fuel pressure test gauge to this adapter. The other method is to use an adapter between the throttle body assembly and the pressure line.

What kind of fuel lines does a Howell TBI use?

The Howell system comes with rubber fuel lines to and returning from the TBI. We have never felt comfortable with these rubber lines over the engine. Emery was the first I know of that put flexible stainless shielded Teflon lines to his TBI. Manny converted his last year and promised to help Mr.C and me to get lines for ours.

Where is the fuel pump on a GM Truck?

As you’re already aware, the throttle body fuel injection system on your 1987 to 1995 4.3L, 5.0L, or 5.7L pickup (or SUV) uses a low pressure (12 PSI) electric fuel pump located in the gas tank. And although GM did not include a Schrader valve to which you could connect a fuel pressure gauge, it can be tested with one to find out if the fuel

Where is the throttle body fuel pump located?

As you’re already aware, the throttle body fuel injection system on your 1987 to 1995 4.3L, 5.0L, or 5.7L pickup (or SUV) uses a low pressure (12 PSI) electric fuel pump located in the gas tank.

What causes a truck to stall when gas is released?

The truck idle drops and lopes and occasionally completely stalls. This usually happens when driving slow in town… backing out of parking space, letting off gas when coming to a stop sign or to park etc. It does fine to start and accelerate. I have done a tune up including oil and filter, fuel filter, spark plugs, wires, cap and rotor.

What causes a Chevy C / K 1500 to drop in idle?

In order to change these, you have to completely removed the distributor and completely disassemble the distributor to get the pickup off and replace it. These components are very sensitive and when failing, will cause misfire, idle issues, and cause it to burn rich as well. 11 out of 12 issues like this are because of this pickup coil.

What are the symptoms of a fuel pump relay problem?

1. Engine stalls One of the first symptoms of an issue with the fuel pump relay is an engine that suddenly stalls. If the fuel pump relay has an issue while the vehicle is operating it will cut off power to the fuel pump, which will cause the engine to stall.

When did they start putting inertial switches on fuel pumps?

So you could have an ignition problem of some sort giving the appearance of a fuel pump problem. I don’t recall if they started putting inertial switches in series with the pump back in 1985 or not (I don’t think they did).

What happens if the fuel pump is stuck?

The injectors could be stuck open, but all the right side are electrically connected together, same with the left. Both sides are ground controlled. There would be ALOT of fuel running into the engine, engine would hydrolock. The fuel pump relay is ecm controlled (ground), also the oil pressure switch is a redundant power supply to the pump.

What should fuel pressure be on a TBI fuel injection system?