Where is the idle button on a GM TBI?

The “A” and “B” terminals are located on the top right of the connector. Unplug the IAC valve located on the passenger side, rear of the throttle body. Start the engine. Insert a T-30 size Torx driver into the Idle adjustment screw that is located behind the plug removed earlier.

Is the Chevy TBI 454 having Idle problems?

Recently rebuilt the 454 in my 1990 TBI Burb. I am having a terrible time with getting it to idle smooth. The engine has a little over 500 miles on it. I have spent countless hours going over the engine looking for vacuum leaks and believe every thing is OK on that front.

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

When did I replace the IAC on my Chevy TBI?

I have replaced the engine temp sensor, the connections to the coil, the coil, cap, rotor, plug wires, map, checked the tps, reset the base idle, checked voltage values at the tps connection, map connection etc. The iac was replaced about 4000 mles ago. The throttle body was re-bushed about 4000 miles ago.

What’s the idle time on a GMC TBI?

IAC 160 steps, throttle sensor . 43 volts, map sensor 2. 15 V, rpm 800,egr duty 0%, throttle angle 0%, injector pulse 4. 3ms, knock sensor 179, engine run time 2 seconds, Well it is not an exhaust restriction. I dropped the exhaust piple down and started her up. Still stalled out in about 2 seconds or less.

What makes a 95 TBI Chevy run crappy?

2–EGR….did you use the VIN # and go to the dealer for the correct one? to test it ,disconnect the vacuum line and plug it and go for a ride. 3–When I removed the cat on mine ,the 02 sensor set the check engine light on and was going thru more gas but didn’t run crappy.

What should fuel pressure be in a TBI?

So, basically I rebuilt the TBI. New injectors, fuel pressure regulator, cleaned the IAC and the ERG valves. Installed new plugs, wires, cap, rotor, fuel filter, and O2 sensor. I checked the fuel pressure and it is reading 11psi down to about 7psi.

How does the GM TBI fuel injection system work?

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 the throttle body above the throttle plate.

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.

What’s the problem with my 1991 Chevy K2500?

I have searched the forums and found similar threads but nothing seems to fix my problem. I have a 1991 K2500 with the 5.7 350 TBI. Problem is when I first start the truck in the morning (or after sitting awhile) and go to take off, it will chug, bog out, or barely go for a few seconds, then snap out of it and run fine.

What’s the idle RPM on a 1993 Chevy truck?

Ok here is my issue I have a 1993 k1500 with a 5.7 tbi when at idle it has a low to the idle. It flacuates between 350 and 1000 rpm. I has so far replaced distributor, cap, rotor, plugs, wires, cts, iac, o2 sensor, map sensor and tps.

How do you change the idle speed on a T-30?

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. Reconnect the IAC valve.

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.

Why does my TBI 350 have zero power?

This weekend I put a new idle air control valve and o2 sensor in, and the symptoms still persist. Along with the erratic idle, the engine has absolutely zero power. It stumbles as if it’s missing a couple of cylinders when you accelerate.

What should the idle speed be on a GM TBI?

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.

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”.

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.

Why does my 91 Chevy 1500 die at idle?

WORKING ON MY 91 CHEVY 1500 4BY4 . MY PROBLEM IS THE MOTOR DIES AT IDLE IT HAS THE 5.7 TBI. WHEN YOU LET THE MOTOR WARM UP IT WILL JUST DIE OUT AFTER ABOUT 5 MINUTES IDLE TIME BUT WILL START RIGHT BACK UP THEN DIE AGAIN MAYBE 2 MINUTES LATER. IF I PUT IT RIGHT IN DRIVE AND GO IT WILL RUN FIND UNTIL I HAVE TO STOP THEN IT WILL DIE OUT AGAIN.

What causes Extream high idle problem on Chevy 1500?

Two things come to mind very quickly. 1. Leaky throttle body base gasket.Very comon on this engine.I don’t know if you serviced this when you pulled the intake. 2.Misadjusted or bent throttle linkage.You don’t know what was done before you got to it.

What’s the idle speed on a 1990 Chevy?

Not open for further replies. I bought a 1990 Chevy 1500 pickup several months back. it idles around 1500 to 1800 rpm and it is tearing the transmission apart.

Where is the fuel injector on a GM TBI?

Why does my Chevy Truck start and idle?

Not sure why this test caused a better and longer gas flow than the above test of just putting the ignition in the ON position and seeing how much gas comes out of the line before the fuel filter. Last test says to start the vehicle and remove the relay.

Can a bad throttle position sensor cause idle surging?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges. 3) Check Engine Light

What causes a GM TBI engine to idle high?

IAC count, EGR percent,TPS etc.They all have an effect on idle speed and may not set codes in an OBD 1 system.Don’t forget a leaking pcv valve (Too obvious).Also a bad coolant temp sensor or connecter.Try wiggle test on 2 wire connecter near thermostat housing with it running.You may get lucky.Harness has been known to go bad at sensor connecter.

What’s the idle speed on a GM Truck?

I recently got to the point of starting the new engine up, and it would idle at 2,000 RPM for 30 seconds or so and then drop to 1200 RPM. Both of these speeds are too high for idle.

Are there any problems with the GM throttle position sensor?

GM Throttle Position Sensor Problems 1 Function and Location. Throttle position sensors (TPS) are usually located on the large butterfly valve that controls airflow into and out of an engine, called the throttle-body. 2 Inconsistent Idle. 3 Engine Stalling. 4 Erratic Shifting. 5 Maladjusted TPS. …

When to clean throttle body 4.3L V6 position sensor?

Clean the throttle body to fix a sticky throttle on a 4.3 in a Blazer, S10, Silverado, and express. Also GMC Jimmy, Sonoma, Sierra, Savana. This applies to 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007.

Why does the idle go up after cleaning the throttle body?

The idle is going to be high at first until the computer relearns the idle again. Cleaning the throttle body allowed more air to enter the engine, and the computer is compensating by adding more fuel.

How long does it take for GM throttle body to relearn?

If you don’t do a relearn procedure, the PCM will “hunt” for a new baseline idle. It will eventually learn it on its own, but it may take over a week of driving, during which time you will experience high and low idle speeds and possibly rough idle. 1) Start the engine and let it idle in park for 3 minutes.

How to do throttle body re-Learn Chevy Malibu?

1) Start the engine and let it idle in park for 3 minutes. During that period the idle may be higher idle than normal. 2) After 3 minutes, turn the engine off and leave it off for 60- seconds. 3) Start the engine again and let it idle in park for 3 minutes one more time. During these run periods you may see a check engine light.

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.

Where is the idle button on a GM TBI?