20 Most Recent 1995 GMC Sonoma - Page 7 Questions & Answers

Is the belt diagram sticker still on the top of the cross brace where the radiator is or on the inside of the hood?

To take the crank sensor out that is broken inside the motor you will need to be creative,use a screw with hex type head tap it in and pull the broken cransensor out.

Inside the fuel take

First you will need to retreive the trouble codes from the computer.

Check your fuel pressure it should be 41-47 with key on and engine off.Sounds like the fuel pump is weak.You might want to check the fuel filter too it could be clogged.

Hi Greg:On 1995 GMC Truck Sonoma 4WD 4.3L TBI 6cyl the Oxygen Sensor is located under hood, driver side, lower engine area mounted in lower exhaust manifold at pipe flange.Fig.: Removing the oxygen sensor from the exhaust pipeThe sensor uses a permanently attached pigtail and connector. This pigtail should not be removed from the sensor. Damage or removal of the pigtail or connector could affect the proper operation of the sensor. Keep the electrical connector and louvered end of the sensor clean and free of grease. NEVER use cleaning solvents of any type on the sensor! The oxygen sensor may be difficult to remove when the temperature of the engine is below 120?F (49?C). Excessive force may damage the threads in the exhaust manifold or exhaust pipe.Hope this helps; also keep in mind that your feedback is important and I`ll appreciate your time and consideration if you leave some testimonial comment about this answer. Thank you for using FixYa, have a nice day.

this is run on vacuum on the top of the tranfer case there is vacuum lines and a transfer vacuum switch pull the vacuum line off and see if there is oil in one of the lines there will be 3 lines on it, if there is you need to change that switch, i had this problem on my 95 sonoma and it fixed the problem, also does your heater go from defrost to the floor some times. it could also just be a small hole in a vacuum hose. there is alot of them under your truck

sound like heater box has issues. doies the heater box have trash in it, like leaves???? It might be a vacuum line dry rottering and making the dampher not work properally. I need to be there to really check it out??????

There isn't a modulator on this trans as it is electronic

You can have first gear going forwrd but no reverse. It is possible. The low/ reverse clutch isn't needed to go forward.

Hello In my 25 years of experience I've really only seen few things that cause this, one is that the built in pressure check valve in the outlet of the in tank electric fuel pump leaks, this causes the fuel in the line and filter to flow back into the tank, this creates a void in the fuel line, the pump must fill the line and filter back up before pressure builds and the engine starts and runs smoothly, based on your description of when this happens I would say that is the problem with your truck. The fuel pump is located in the fuel tank, you must remove the tank from the truck or pull the truck bed off to replace the fuel pump. If you replace the pump make sure you also replace the fuel filter or the new pumps warranty will be void. I have a parts site that i order from on line, they are MUCH cheaper than local sources and only sell high quality aftermarket replacement parts as well as ACDelco and other OEM parts. Click here to access this parts site

Have you tried starting the truck up using Starting Fluid? If it starts and runs for a few seconds, you definitely have a fuel issue, and from the sounds of it you may have faulty injectors or fuel pressure regulator. If the starting fluid doesn't start the engine for a few seconds, you may have a spark, or ignition problem. Let me know what happens when you use Starting Fluid and I will help you out further. I’m happy to help further over the phone at https://www.6ya.com/expert/jeremy_69f3cc28d95bf514

yes it gets its vacuum from the engine, the vacuum line goes through the firewall on the passenger side from a vacuum storage cannister that is connected by a hose to the engine intake manifold

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Hi,

My name is Ben and I'm your guru, i.e., mentor, an influential teacher or popular expert: a management guru. - origin from Sanskrit, 'weighty, grave', for today.

Your fuse is merely indicative of a bad ground, unintended grounding, water in the wiring, etc.

With that in mind, let's begin.

First Step:

Do a Thorough Visual Inspection
Do a thorough visual and "hands-on" underhood inspection before starting any diagnostic procedure! You can find the cause of many problems by just looking, thereby saving yourself a lot of time.
• Has the vehicle been serviced
recently? Sometimes things get
reconnected in the wrong place, or
not at all.
• Don't take shortcuts. Inspect hoses
and wiring which may be difficult to
see due to location.
• Check sensors and actuators for
damage.
• Inspect the illumination system wires for:
- Damaged terminals.
- Split or cracked connectors
- Splits, cuts or breaks in the inline fuses, circuit brreaker
wires and insulation.
• Inspect all electrical leads for:
- Correct wiring routing. Refer to vehicle
service manual.
- Pinches and kinks.
- Splits, cuts or breaks.
• Inspect wiring for:
- Contact with sharp edges.
- Contact with hot surfaces, such as
exhaust manifolds.
- Pinched, burned or chafed insulation.
- Proper routing and connections.
• Check electrical connectors for:
- Corrosion on pins.
- Bent or damaged pins.
- Contacts not properly seated in
housing.
- Bad wire crimps to terminals

Step Two:

Discussion: Late model vehicles are highly computer controlled to reduce emissions, maximize fuel economy and improve consumer comfort. The various control systems in vehicles are interrelated and controlled by multiple computers,sensors, relays, and circuit breakers that constantly monitor vehicle performance through a myriad of sensors located throughout the vehicle. Based on information received, the computers adjust the vehicle performance through a series of valves, switches and motors. You must use a scanner to unlock the information stored in your car's computer. Your GMC is OBD I compliant.

A Scan Tool can be used to read and erase trouble codes, display, record and play back LIVE diagnostic data and perform other tests allowed by the vehicle maker. Scan tools that cover vehicles 1982 to present are available at your local auto supply dealer.

You don't indicate any diagnostic tests to date. A GM dealer or your local mechanic will charge $100-$200 to perform a diagnostic scan. However, AutoZone will provide a thorough scan for FREE.

Anyone who tells you that a modern vehicle can be diagnosed without a scanner with the problems you have set forth is merely guessing. You car has a computer and memory and probably knows exactly what the problem is. That on-board computer is just waiting for you to ask, "What's wrong". All of the suggestions that I can ;make would of necessity be based on the scanner readings

Irrespective of what anyone tells you, there is but one way of diagnosing your problem. If I were to make a suggestion, it would be -- at best --. a mere guess. A diagnostic scan retrieves any inform related to the malfunctioning parts and tells you precisely what is wrong. Perform the scan diagnostic now.


All the best,

Ben

Turn ignition forward a few times just far enough for accesories to come on(then try to start)

Not too big of a deal. Disconnect battery.
Remove driveshaft from vehicle. Disconnect any electrical wiring from transmission. Remove starter. Remove gear shifter. Support transmission on a transmission jack, or a good sturdy floor jack. Remove rear transmission mount, and crossmember. Lower transmission slightly to help gain access to the engine-to-trans bolts. Unbolt slave cylinder and hang it out of the way. Remove engine-to-transmission bolts, and bouncer bars (if equipped) Slowly pull transmission away from engine. If it's stuck, double-check to make sure all the bolts are out, then try raising or lowering the trans a bit with the jack and/or pry in between with a pry bar to help break it loose. Remove transmission from vehicle. DON'T lose the dowel pins! They are needed to line up the engine to the trans properly. Remove clutch pressure plate from flywheel, and remove pressure plate, and clutch plate. If the rear main seal is leaking (behind flywheel) NOW is the time to change it (cheap $10 part) Installation is in reverse of removal. Good luck!!

I had that problem on an older GM but I discovered that if you could wiggle the starter around and get it in a vertical position it would drop down as long as the solenoid was turned the right way. This may work for you, otherwise you will have to remove the brace. Hope this helps.