Need good fuel injector cleaner

Try with some of the basics first. When was the vehicle last given a full service? Dirty air and oil filters can affect an engine's idle speed. Old spark plugs also affect idle. Once it has been serviced try putting some fuel injector cleaner through the system. Use this method.
Start with the fuel tank at a very low level usually just as the fuel light comes on, (If it has one). Add the correct measured amount of cleaner to the fuel tank. This will give you a stronger mixture. With the engine cold, start the engine and let it idle. DO NOT rev the engine as this will thin the mixture making it less effective.
Let it idle up to working temperature and for about 5 minutes more. Calmly drive to a fuel station and Fill the tank to the top. Add the rest of the cleaner then drive as normal. Personally I would take the vehicle for a good trip out to check the vehicles revs at different speeds. When you get the fuel light on again you can fill as normal or add One more dose of cleaner.
If this doesn't work You could have a vacuum leak somewhere on the system. These can be a pain in the tailbone to find so I would suggest getting a Good mechanic to look and listen to it to hunt out the leak.

Does it have spark ? Instead of trying to test fuel pressure , spray carb cleaner into the engine through the throttle plate or vacuum hose an see if it starts an runs ,at least till carb, cleaner is used up. What engine does it have ?

Engine Controls and Fuel - 2.8L
Engine Controls and Fuel - 3.6L
Engine Controls and Fuel - 6.0L

Fuel Rail
The fuel rail consists of 3 parts:
• The pipe that carries fuel to each injector
• The fuel pressure test port
• Six individual fuel injectors
The fuel rail is mounted on the intake manifold and distributes the fuel to each cylinder through the individual injectors.

You have to take the plastic cover off the top of the engine to see it .

there's a shraeder valve to easily de-pressurize the fuel system before working on removing the injector...



you need to remove that plastic "beauty plate" to see the intake plenum/ manifold

he shows you how to unplug the electrical connector from that fuel injector

from there, someone else maybe chime in on how to disconnect the hose from the injector if you have a similar setup as that youtube link

PS: make sure you lube the o-ring of the injector before installing How to change fuel injectors

The fuel injectors are not working as the should. Run some premium fuel and fuel injector cleaner to try and make problem go away.
It problem persists the injector computer circuit voltages require checking. Possible injector controller or injector replacement could be solution.

You can purchase Salvage units at Carparts.com. This is a nationwide network of Salvage yards which have some warranties, ship to your door and provide you some choices in prices and condition of the parts.

You can also look to the internet and search for rebuilt brain units.

If you are having drivability problems, you can tell us why someone thinks its the computer. For instance, the Northstar engine requires a special solvent to be introduced into the fuel injectors annually. This strong chemical needs to sit overnight inside the engine to work.

Your valves can soot up without this periodic service.

Sorry, can't give you a price for either repair, but Salvaged parts can be good especially with rear end collisions or trans failures. Front end collisions with the engine on may have a shorted brain. You will see a large variance in offered prices.

Please rate my info.

P0174 System Too Lean (Bank #2)
P0171 System Too Lean (Bank #1)

System to lean means that a fuel injector or injectors may be plugged up, or the oxygen sensor is sensing too lean of a condition.

How many miles do you have on this engine?
Have the O2 sensors ever been changed?

When was the last time you had a tune up?

There can be a misfire too from the cylinders.

An engine that hesitates, stumbles or misfires when accelerating or when it is under load is an engine that is either sucking too much air, not getting enough fuel or misfiring. If the Check Engine Light comes on, you may find any of the following codes:

• P0171, P0174 Lean fuel condition codes
• P0120 to P0124 Throttle position sensor codes
• P0222 to P0229 Throttle position sensor codes
• P0400 to P0409 EGR related codes

If there are no misfire codes, a common cause of acceleration stumble is a bad throttle position sensor (TPS). The TPS tells the computer how far the throttle is open. The computer uses this information to determine how much fuel is needed to maintain the correct air/fuel mixture and when extra fuel is needed if the throttle suddenly opens wide.

Another common cause is dirty fuel injectors. If varnish deposits have built up in the tips of the injectors, they won’t spray as much fuel as they normally do, or will “dribble” fuel instead of spraying a fine mist. This creates a lean fuel mixture and conditions that are ripe for stumble and hesitation (also misfire). Look at short term fuel trim (STFT) and long term fuel trim (LTFT) with your scantool. If the numbers are high, it tells you the engine is running lean and the injectors need cleaning. Treat mild cases with a high quality fuel-injector cleaner additive. Severe cases require professional cleaning equipment.

Also if this sensors apply to your vehicle, camshaft sensor or crankshaft sensor if sensors bad you don't get any spark.

Good luck and rate this solution, please.

hi,

are you familiar with the northstar engine?
first generation northstars are notorious for this kind of thing..
the engine is prone for metal fatigue/ warping of the heads, and stripped out head bolts, do you have documentation and service history for it?
these engines need a good mechanic to inspect and replace head bolts which strip out and need fixing. I will post a link at the bottom
once the engine is repaired correctly it should last a good long time
have it fixed correctly. I think someone has turned up the idle knob in an attempt to get the coolant flowing quicker to keep it cool.
its worth repairing if you have the money..

jm

http://www.cadillacforums.com/forums/northstar-performance-technical-discussion/976-overheating-northstar.html

check spark plug and wire condition, try servicing injectors and check fuel preasure regulator

this cars are very coming with the leak at the fuel pressure regulator, all you have to do is locate the regulator for the fuel, it is on the fuel injector rail, and unplug the vacum hose if you see any fuel or smell like fuel inside the hose that means the regulator has to be replaced,