Question about 2004 GMC Envoy SLT

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Why there is no spark at the spark plugs? what is all the cause for no spark?

When cranking there is no spark at the spark plugs when i test for spark. the engine was running good with no problem when i turn the key off and tried to start the engine again the engine would turn over but it want start what could have happen that quick? no service engine light was on when the engine was running. 2004 GMC Envoy SLT 4.2L i hope the Expert can answer my question with a correct answer i don't want to put any parts on that's not need.

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  • GMC Master
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Try this link might help you out.... How to Diagnose Loss of Spark in Your Car Engine

Posted on Dec 10, 2016

  • 6 more comments 
  • Joe Russell Dec 10, 2016

    the 2004 GMC Envoy SLT 4.2L don't have a single coil it have the coils on the spark plugs the link you sent me wasn't helpful so what are the basic things that cause no spark?

  • NOEL
    NOEL Dec 10, 2016

    Engine Cranks But Won't Start
    The first step is to determine if it’s a spark, fuel, or compression problem. Here’s a quick way to find out which of the three is missing. Remove a plug wire, insert a Phillips screwdriver or spare plug piece of bare wire into the plug wire boot and place the end near the engine block (do not hold the plug wire while cranking the engine unless you want a shocking experience). If there’s a spark when the engine is cranked, it has ignition. The problem is either fuel or compression. If the engine has an overhead cam with a timing belt, loosen the cover over the timing belt and check the belt. If the belt is okay, the problem is no fuel. Listen for the electric fuel pump in the fuel tank to make a buzzing noise when the ignition is turned on (you may have to open the gas cap to hear it). You won’t hear anything if the pump has died. Diagnostics can now be focused on the fuel pump circuit to determine if the pump, relay or wiring is causing the no start. If the relay has voltage but the pump isn’t running, you’ll probably have to drop the fuel tank to check the wiring connector at the pump. If the problem is no spark, anything in the ignition circuit that creates the spark may be at fault. Use your AutoTap Express DIY to look for an RPM signal from the Crankshaft Position sensor while cranking the engine. A bad Crankshaft Position sensor is a common cause of no starts. The signal from this sensor goes to the PCM or ignition module that switches the ignition coil(s) on and off. If you have an RPM signal, a bad ignition module or PCM may not be switching the coil(s) on and off. Using a voltmeter, check for voltage at the coils with the key on and while cranking the engine. The voltage should be switching on and off. In ignition systems with a single coil and distributor, a bad coil or a cracked distributor cap or rotor can prevent the spark plugs from firing. On multi-coil, distributorless ignition systems and coil-on-plug systems; one coil failure may cause an engine to misfire, but it won't prevent it from starting. What’s causing the no-start? All engines require three things to start and run: spark, fuel and compression. If any one of these isn’t there, you aren’t going anywhere....

    What’s causing the no-start? All engines require three things to start and run: spark, fuel, and compression. If any one of these isn’t there, you aren’t going anywhere.
    Symptom:
    Engine Cranks but won’t Start
    Probable Causes:
    Fuel Pump (P0230 to P0233)
    PCM (P0600 to P0606)
    Crank Sensor (P0355 to P0399)
    Fuel Pressure (P0190 to P0194)
    Chances are the Check Engine Light is not on, but you may find any of the following codes:

    P0230 to P0233 Fuel Pump codes
    P0600 to P0606 PCM related codes
    P0335 to P0339 Crank Sensor codes
    P0190 to P0194 Fuel Pressure Sensor codes
    No spark due to a bad crank position sensor, a faulty ignition module or PCM, a problem in the ignition circuit (ignition switch, antitheft system, wiring, etc.), a faulty park/neutral safety switch, a bad ignition coil (only on engines with a single coil ignition), or wet plugs or plug wires (did it rain last night, did you just wash the engine?)

    A less common cause is a worn starter that draws so many amps while cranking the engine that there’s not enough juice left to adequately power the ignition system and fuel injectors. Contributing factors might be a weak battery and/or loose or corroded battery cables.

    No fuel because of a dead fuel pump, bad fuel pump relay, blown fuel pump fuse, plugged fuel filter or line, or failed PCM injector driver circuit or injector power supply relay. Or, the fuel tank might be empty (don’t believe what the gauge is telling you), or the fuel tank might contain contaminated fuel (water or too much alcohol) or the wrong type of fuel (whoops, somebody put in diesel instead of gasoline).

    No compression because the timing belt or chain is broken, the timing belt or chain is loose and jumped out of time, or the overhead camshaft has snapped. A powerful scantool like AutoTap Express DIY can help isolate the root cause

  • Joe Russell Dec 10, 2016

    there is no spark at the spark plugs when cranking the fuel pump run when turn the key on i don't have a auto tap express diy scan tool to check for rpm signal from Crankshaft Position sensor while cranking the engine. i just bought a Innova 3040c scan tool will it check for rpm signal? there is voltage at the coil when key is on but there is no signal on the trigger side of the coil when cranking or do i just check for voltage on one side of the coil the pink wire? the coils is on the plugs the codes i found is P2101, P1516, P2119 these codes was read after the battry cable been disconnect the vehicles was running good with no problem until i turn the engine off then it wouldn't start back up. the security light is on when turn key on but it go out in about 5 seconds how do i reset the security light? i do notice when i turn the key to cranking sometime when i turn the loose the starter will keep turning for a few seconds will that cause no spark is something wrong with the ignition switch? i didn't the engine service light on while driving. please help to find the problem. thank you

  • NOEL
    NOEL Dec 11, 2016

    if you have checked all of the above then i would get the ignition switch checked out,also get the trigger side looked at.

  • Joe Russell Dec 11, 2016

    i don't understand this, at the begining of the cranking i can see spark at the coil on plug but it spark for only a few seconds and stop when cranking why? i connected a multimeter to the connector on the crankshaft position sensor and it show 5.0 ACV voltage when cranking if i can find out why no spark i believe the engine start how do i check and ignition switch and the resitiance on a crankshaft position sensor? as i stated before when i turn the key loose the starter will keep turning for a few seconds why it do that?

  • NOEL
    NOEL Dec 11, 2016

    The ignition coil is what generates the spark, so if it's present at the right times but weak, the coil is usually to blame. It is a voltage amplifier. If only a portion of the coil inside it shorts, it will partially amplify the voltage so the spark will be weak. The point being that a failed ignition coil isn't necessarily completely dead, there are degrees of failure so to speak.

    You didn't mention replacing the ignition wires, which can also cause a weak spark if the internal resistance is high, but that's not common. Usually faulty wires will leak the voltage externally and cause an outright misfire, and that usually happens when they're wet. If you wash your engine and if misfires, worn out ignition wires or a distributor cap that isn't sealing out water are the usual problems. If you can wash your engine bay and it runs normally afterwards (including a test drive), then you can pretty much rule out distributor and ignition wire problems. The coil is also normally immune to water as long as the ignition wire between it and the distributor is sealing properly. If the coil is sensitive to water and the ignition wire is new, then the coil housing is cracked or open somehow and thus can be considered failed....
    try this link as well...http://www.aa1car.com/library/ignition_c... could also be a faulty distributor...if all this does not work then i am lost as well.

  • Joe Russell Dec 11, 2016

    this vehicle don't a distributor it have the coils on the plugs six of them can you tell me how to check for resistance on the crankshaft position sensor with a multimeter what the number should be for the resistance if any?

  • NOEL
    NOEL Dec 11, 2016

    try this link then..https://www.1aauto.com/content/articles/... this one..http://atlib.info/blog/133-how-do-i-chec... this..http://easyautodiagnostics.com/misc-inde...

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2 Answers

Got 2004 dodge stratus misfiring code says p2305 already changed coil and spark plugs and wires still misfiring


Who is doing the parts replacing?

Have you looked at Scan Tool Data & road tested?

Have you actually done any testing, to find a problem
& used the codes to component test

Till you answer that, I will say you need a repair shop

Lots of things cause misfires

Changing spark plugs & a coil or two ,based on a code,
is not doing the required testing to find a problem or the
need for parts just yet

Nov 23, 2014 | 2004 Dodge Stratus

1 Answer

Cranks won't start


First you must check to see if engine is mechanical sound by performing a compression test. remove the spark plugs install a compression gauge in the spark plug hole and crank engine about 4 cycles compare readings to all cylinders reading should be around 125-150 psi readings in the 50 psi range possible jumped or broken timing belt. If engine is mechanically sound test for spark at the spark plugs use a spark plug laid against valve cover and have some one crank it over look for the spark to jump the gap. A no spark problem is internal in the distributor.

Nov 07, 2013 | 1995 Honda Accord

1 Answer

Had my truck tested,it said cylinder 1 misfire.what is causeing this?


Possible causes: bad spark plug, plug wire, coil, injector not working or stuck-clogged, or an internal mechanical problem where compression is lost on #1-like a bad valve not seating, or head gasket...To check for a mechanical condition, do a compression test.
First thing to do is pull the spark plug and check it or swap in a known good one. Check the spark on #1-should have a blue snapping spark when the engine is cranked. If so, not the coil or the wire. Keep looking. Good luck.

Sep 26, 2013 | 1997 Dodge Dakota

1 Answer

Crank position sensor


Check if you have spark on a plug wire when it is cranking over and wont start. If you have no spark, a good guess is the crank position sensor. Often the cause of no spark, but could also be the ignition control module, the camshaft position sensor, or the pcm. If you want to be sure before replacing the sensor, have the sensor tested while on the car. A shop could test it.

Dec 29, 2012 | 1997 Buick LeSabre

1 Answer

Will crank and run fine when engine is cold go for drive come back wont start, new battery1 will turn over just like no fire is getting through1


could be a number of possible faults.1/crank sensor not working when hot,trace this and pour cold water on it(dont do this if it is not by crank pulley as water isnt good for modules etc) and retry.2/sparkplugs worn,but usually they would fault more on cold start.3/fuel pump cuts out when run,try wacking tank from underneath and retry.though I would concentrate on nil spark caused by a faulty ignition module or crank sensor.
Next time it fails to start.pull off a sparkplug lead,make a quick test plug with an old(but working)sparkplug.pull the side wire away from the center electrode 5mm and insert into plug lead.earth ground the plug on its thread against metal on the engine.crank and check for spark visually,don't be tempted to hold the plug while cranking.if nil spark we will have to test further which is faulty sensor.if it sparks ok we will need to test for fuel.
testing for fuel is easy.
when it fails,unclip air filter housing,while engine is being cranked,spray an aerosol based carburettor cleaner into air duct to engine,it should start and run while spraying and stop when you stop spraying if fuel delivery is the fault.fuel pump will then need testing/replacing.
be careful not to spray onto ignition or any areas of spark

Feb 11, 2011 | 1994 Lexus LS 400

1 Answer

Car cranks but will not start.


You turn the key to start and hear the starter motor crank the engine, but when you release the key, the cranking stops and there is silence. This means that the battery and starting motor are working properly, but the engine is not firing. If you continue cranking the engine over in this way, the battery will eventually run down and will need to be recharged, but the battery and starter are not the cause of your problem.
There are a number of causes for this type of no-start condition, the most common being that you are simply out of gas. Assuming that you have fuel in the tank, you will need to go through a series of tests to determine what is causing the problem. The testing procedure is as follows:---

Spark:---------An easy way to test for spark is with an inexpensive spark tester. This is a device that is readily available at most auto supply stores. You use it by simply holding it next to a spark plug wire. If you see the neon lamp flashing while someone cranks the engine, then you have spark and should move on to checking for fuel. If there is no spark, or a very weak spark, you will have to replace the spark plug or the coil pack.It has to be checked.

Fuel:
First step here is to listen for the fuel pump running inside the gas tank. When you turn the key to run, you should easily hear the pump come on, run for a few seconds to build fuel pressure, then turn off. If you do not hear it, it could mean that the fuel pump or circuitry is bad. (Fuel pump failure is a common problem).

Fuel injected cars are very sensitive to proper fuel pressure. If the pressure is off, even by a few pounds, it will cause noticeable performance problems, or a no-start condition. To check for proper fuel pressure, you will need a fuel pressure gauge that is suitable for your type of system. Or you can also get the fuel pressure tested at local car garage, If fuel pressure is low then its a fuel pump and fuel filter related problem.

Compression:

If you know that you have spark and fuel, the next step is to check for compression. For this, you will need a mechanic's grade compression tester that will screw into a spark plug hole. You will need to remove the spark plugs and use the compression tester to test the compression on each cylinder. If the compression is very low on all cylinders, that is a sure sign that the timing belt (or timing chain depending on the engine) has failed and will have to be replaced.

-------------
This troubleshooting will let you know the problem.Thanks.

Jan 20, 2011 | 2004 Hyundai Santa Fe

1 Answer

My car cranks but i will not start at times. What could be the problem?


You turn the key to start and hear the starter motor crank the engine, but when you release the key, the cranking stops and there is silence. This means that the battery and starting motor are working properly, but the engine is not firing. If you continue cranking the engine over in this way, the battery will eventually run down and will need to be recharged, but the battery and starter are not the cause of your problem.
There are a number of causes for this type of no-start condition, the most common being that you are simply out of gas. Assuming that you have fuel in the tank, you will need to go through a series of tests to determine what is causing the problem. The testing procedure is as follows:---

Spark:---------An easy way to test for spark is with an inexpensive spark tester. This is a device that is readily available at most auto supply stores. You use it by simply holding it next to a spark plug wire. If you see the neon lamp flashing while someone cranks the engine, then you have spark and should move on to checking for fuel. If there is no spark, or a very weak spark, you will have to replace the spark plug or the coil pack.It has to be checked.

Fuel:
First step here is to listen for the fuel pump running inside the gas tank. When you turn the key to run, you should easily hear the pump come on, run for a few seconds to build fuel pressure, then turn off. If you do not hear it, it could mean that the fuel pump or circuitry is bad. (Fuel pump failure is a common problem).

Fuel injected cars are very sensitive to proper fuel pressure. If the pressure is off, even by a few pounds, it will cause noticeable performance problems, or a no-start condition. To check for proper fuel pressure, you will need a fuel pressure gauge that is suitable for your type of system. Or you can also get the fuel pressure tested at local car garage, If fuel pressure is low then its a fuel pump and fuel filter related problem.

Compression:

If you know that you have spark and fuel, the next step is to check for compression. For this, you will need a mechanic's grade compression tester that will screw into a spark plug hole. You will need to remove the spark plugs and use the compression tester to test the compression on each cylinder. If the compression is very low on all cylinders, that is a sure sign that the timing belt (or timing chain depending on the engine) has failed and will have to be replaced.

-------------
This troubleshooting will let you know the problem.Thanks.

Jan 19, 2011 | 1997 Saab 900

4 Answers

My car will not start, it turns over but wont ignite. i have changed the plugs, wires, distributor cap, rotor, and ignition coil. i am at a loss on what else could be causing this.


fuses, relay, corrosion at wire connections, ignition switch, pick up coil, ignition control module. Is the distributor rotor turning when you crank the engine? I ask this because a broken timing belt would cause a no start condition.

Jan 04, 2011 | 1990 Geo Metro

3 Answers

The engine turnes but it wont start.


Free Auto Repair Advice by Professional Mechanics




Troubleshooting / Car Engine Cranks but Will Not Start / Engine Crank But Wont Start 2

* Why does my engine stall at idle?
* How do I change my spark plugs?
* Why does my engine stall?
* Why does the engine stall after replacing the battery?
* Why won't my engine crank over?
* How to retrieve trouble codes
* How to test fuel delivery system
* Engine cranks excessively
* Engine has excessive smoke
* Rapid ticking sounds when engine is cranked
* How to tune up your engine
* How to jump start your engine
* How to test an oxygen sensor
* How to open a car hood
* How a flywheel - flex plate works

Engine Cranks But Will Not Start

For an engine to run, you need three things to happen inside the engine, compression, fuel and ignition, without any one of these components the engine will not run. Follow the repair guide below:


Engine Configuration with Camshaft Operation

*

Compression - Engine compression caused by crankshaft rotation and pistons moving up and down inside the engine block. If the timing belt or timing chain fails it will cause the camshaft to become out of correlation with the crankshaft or allow the camshaft to stop rotating. Either of these conditions will cause the engine to lose compression and sometimes cause internal engine damage.
*

Fuel Delivery System - The fuel system includes: fuel pump, fuel injectors, pressure regulator, fuel filter and pressure lines. This system is used to supply fuel under pressure to the fuel injection system, the lack of fuel pressure or volume will cause the fuel delivery system to fail and the engine to stall or not start.
*

Ignition Spark Delivery System - The ignition system components include: spark plugs, spark plug wires, distributor (if applicable), crankshaft angle sensor, camshaft angle sensor, ignition coil, ignition module, knock sensor and PCM (engine control module). The engine relies on the ignition spark to be delivered to the combustion camber at the correct time. If the ignition spark stops or is delivered at the wrong time the engine will not run or run poorly.

If your engine cranks but does not start follow this troubleshooting guide:
* Step 1 - Anytime you have a problem with electronically controlled components such as an engine, transmission, ABS brake, or SRS (supplemental restraint system, Air Bag) inspect all fuses using a test light and check the under hood power distribution center and under dash fuse panels. If all fuses test ok continue to the next step.
* Step 2 - To check for problems with electronically controlled components such as an engine, transmission, ABS brake, or SRS (supplemental restraint system, Air Bag) and the fuses test ok a trouble code scan is needed to identify any system trouble. Use a simple scanner tool to retrieve trouble codes and see if they relate to the specific problem, like a crank angle sensor failure code. If the trouble code present does not pertain to the immediate problem like an EVAP code ignore it until a later time, after the car is running. The reason we repair non-related codes after the engine is running is because sometime false codes can be triggered by the engine not running. Once the engine is running again the code present might cycle and turn itself off. You might say "if the engine doesn't run shouldn't it have a trouble code?" Sometimes conditions occur that will not be detected by the computer, example: if the fuel pump fails the computer cannot detect the failure, so the engine doesn't start and the computer thinks everything is ok with no codes. If no trouble codes are present proceed to the next step.
* Step 3 - The spark plugs in your engine are used to ignite the compressed fuel air mixture. If the condition of the spark plugs are fouled by excessive fuel or carbon the engine will not start, backfire or run rough. Remove all spark plugs to inspect their condition. Please use this spark plug condition reference guide to see how the spark plugs are operating.
* Step 4 - Determine if the engine has compression, this can be done a number of ways but the most complete method is to perform a compression check. Remove the spark plugs and perform a compression test on one cylinder. If one cylinder has compression then the remaining cylinders usually will be close to the same. Crank the engine over about 5 seconds, normal compression readings should be between 125 psi and 160 psi on each cylinder. If no or little compression exists additional tests will be needed. The most common reason for an engine to lose compression is a timing belt or timing chain failure. If low or no compression exists remove the oil fill cap and observe camshaft rotation when the engine is cranked over. If no rotation exists the timing belt or chain has failed. If your engine has a timing belt and you cannot see the camshaft easily remove the upper bolts to the timing cover and gain visual access to the belt, recheck cam rotation by cranking the engine over. Sometimes a timing belt or chain can jump causing the camshaft to lose correlation with the crankshaft and therefore causing low compression. The best test for this condition is to remove the timing belt/chain cover and inspect timing marks. If the compression is ok proceed to next step.
* Step 5 - Test the ignition system output, ignition systems can vary in configuration but operate on the same principal. Ignition systems can consist of a coil, pick up coil, crank angle sensor, cam angle sensor, spark plugs, spark plug wires, distributor cap, ignition rotor and a distributor and any variations of these components. An ignition coil is a voltage stepper coil that transforms a low voltage (12 volts) signal into tens of thousands of volts needed to jump the gap of the spark plug. This coil is activated by an ignition module triggered by using the camshaft/crankshaft angle sensor; timing is adjusted by the ECM (computer).

Hope helps (remember rated and comment this).

Aug 11, 2010 | 1999 Chevrolet Blazer

2 Answers

Cranks but wont start


Engine Cranks But Will Not Start

For an engine to run, you need three things to happen inside the engine. Compression, fuel and ignition, without any one of these components the engine will not run.
Basic Checks:

A. Test Fuses. Test both under hood power distribution center and the fuse panel under dash. This is done with a test light tool. The test light should illuminate on both sides of the fuse, if not the fuse has failed and needs to be replaced.
B. Testing Fuel Pressure Test for proper fuel pressure with a test gauge on the fuel rail, most throttle body injection cars (TBI) are between 13 psi and 17 psi. and most (DPI) direct port inject systems are between 40 psi and 55 psi. If no or little fuel pressure is observed and there is 12 volt power present the fuel pump, the fuel pump needs replacing.
C. Checking Timing Belt Test for compression by removing a spark plug and insert a compression gauge. Crank the engine over about 5 seconds the gauge should read between 125 psi and 165 psi, if no compression is observed remove front engine cover to inspect timing belt or chain. Crank engine to observe cam rotation, if the cam does not rotate the timing belt or chain has failed. (note: if the timing belt drives the water pump it is best to replace the water pump at this time)
D. Test for Injector Pulse Remove injector connector to insert injector test light (node) or volt meter. Observe light flash or gauge pulse while cranking. If light/voltmeter doesn't respond, an ignition distributor/crank angle sensor (CKS) or an ignition module is most likely your problem.
E. Test for Ignition Spark Remove spark plug wire, insert an extra spark plug into end of wire, rest spark plug next to a ground source then crank engine. You should observe a blue spark between the spark plug gap and ground source. If no spark is observed, an ignition coil, ignition rotor or spark plug wires might have failed. (always keep hands away from engine when cranking)

Jul 14, 2008 | Hyundai Motor 2002 Sonata

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