MSD has no spark at distributor

Discussion in 'Fox 5.0 Mustang Tech' started by harveybbc, Jan 30, 2008.


  1. harveybbc

    harveybbc New Member

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    I just got done reinstalling my 5.0 in my 1988 ford mustang with speed density no "no mass air flow".I installed new timing chain cover new oil pan and gasket, new oil pump ,a set of crane roller lifters,new timing chain,new water pump ,new push rods,a pypes x pipe with no cats,mac shortys,mac mufflers new o2 sensors new gaskets all threw the top and bottom,e303cam,polished 70mm throttle body and egr spacer and a new set of injectors.

    My msd distributor got knock off a work bench and cracked the base where the cap locks on.I see no arching to this crack and is high enough where the cap still covers it.

    I am getting great spark at the msd coil I tested the msd ignition module works great.Im getting no spark or maybe a extremely weak spark?I was planning on doing the mass air conversion next do to the e303cam but need to find out why i cant get my car started,The rotor is spinning.

    I put a plug in the end of the wire and cant seem to see any spark unless I use a lawn mower plug even then all i can see is a super lite spark i even turned off all the lights in the garage making it pitch dark and am unable to see any spark threw the iridium or a new set of motorcraft plugs.

    When i first installed the cam i wired it clock wise oppose to counter clock wise and was getting backfires.Right now im wondering maybe i missed a plug somewhere Since i had the motor completely removed?Or did my distributor really break that easily?Any other test i can try to determine whats going on here?Any help would be great thanks in advance.
  2. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    Cranks OK, but No Start Checklist for Fuel Injected Mustangs

    Revised 29-Jun-2007 to update TPS testing procedure for 94-95 Mustangs

    All text applies to all models unless stated otherwise.

    Note: 94-95 specific changes are in red

    1.) Remove push on connector from starter solenoid and turn ignition switch on. Place car in neutral or Park and set the parking brake. Remove the coil wire from distributor & and hold it 3/8” away from the engine block. Jumper the screw to the big bolt on the starter solenoid that has the battery wire connected to it. You should get a nice fat blue spark.
    Most of the items are electrical in nature, so a test light, or even better, a voltmeter, is helpful to be sure they have power to them.
    No spark, possible failed items in order of their probability:
    A.) MSD or Crane ignition box if so equipped
    B.) Coil
    C.) TFI module
    D.) PIP sensor in distributor. The PIP sensor supplies the timing pulse to trigger the TFI and injectors. See paragraph 5A - a noid light will tell if the pip is working by flashing when the engine is cranking.
    E.) No ECC or computer power - ECC or computer relay failure
    86-93 models only: ECC relay next to computer - look for 12 volts at the fuel injector red wires
    94-95 models only: EEC or PCM power relay in the constant control relay module. Look for 12 volts at the fuel injector red wires.
    F.) No ECC or computer power - fuse or fuse link failure
    86-93 models only: Fuse links in wiring harness - look for 12 volts at the fuel injector red wires. All the fuse links live in a bundle up near the starter solenoid.
    94-95 models only: 20 amp EEC fuse in the engine compartment fuse box. Look for 12 volts at the fuel injector red wires.
    G.) Ignition switch - look for 12 volts at the ignition coil red/lt green wire. No 12 volts, blown fuse link or faulty ignition switch. Remove the plastic from around the ignition switch and look for 12 volts on the red/green wire with the switch in the Run position. No 12 volts and the ignition switch is faulty. If 12 volts is present in the Run position, then the fuse link is blown.
    94-95 models only: Check inside fuse panel for fuse #18 blown – 20 amp fuse
    H.) Computer
    J.) Engine fires briefly, but dies immediately when the key is released to the Run position. Crank the engine & when it fires off, pull the small push on connector (red wire) off the starter relay (Looks like it is stuck on a screw). Hold the switch in the crank position: if it continues to run there is a problem with either the ignition switch or TFI module. Check for 12 volts at the red/green wire on the coil with the switch in the Run position. Good 12 volts, then replace the TFI.

    See the following links for wiring diagrams...

    http://www.autozone.com/servlet/UiB..._us/0900823d/80/16/71/3c/0900823d8016713c.jsp for 79-88 model cars
    Computer/fuel pump/ignition wiring diagram, 86 model http://www.autozone.com/images/cds/gif/large/0900823d80167158.gif
    Computer/fuel pump/ignition wiring diagram, 87 model http://www.autozone.com/images/cds/gif/large/0900823d8016715e.gif
    Computer/fuel pump/ignition wiring diagram, 88 model http://www.autozone.com/images/cds/gif/large/0900823d80167162.gif

    http://www.autozone.com/servlet/UiB..._us/0900823d/80/19/59/5a/0900823d8019595a.jsp for 89-93 model cars
    Computer/fuel pump/ignition wiring diagram, 89-90 cars http://www.autozone.com/images/cds/gif/large/0900823d8019595f.gif
    Computer/fuel pump/ignition wiring diagram, 91-93 cars
    http://www.autozone.com/images/cds/gif/large/0900823d80195960.gif

    http://www.autozone.com/servlet/UiBroker?ForwardPage=/az/cds/en_us/0900823d/80/1d/db/3c/0900823d801ddb3c.jsp for 94-98 model cars

    2.) Spark at coil wire, pull #1 plug wire off at the spark plug and check to see spark. No spark, possible failed items in order of their probability:
    A.) Moisture inside distributor – remove cap, dry off & spray with WD40
    B.) Distributor cap
    C.) Rotor
    D.) Spark Plug wires
    E.) Coil weak or intermittent - you should see 3/8" fat blue spark with a good coil

    3.) Spark at spark plug, but no start.
    Next, get a can of starting fluid (ether) from your local auto parts store: costs a $1.30 or so. Then pull the air duct off at the throttle body elbow, open the throttle, and spray the ether in it. Reconnect the air duct and try to start the car. Do not try to start the car without reconnecting the air duct.

    Two reasons:
    1.) If it backfires, the chance for a serious fire is increased.
    2.) On Mass Air cars, the computer needs to measure the MAF flow once the engine starts.
    If it starts then, you have a fuel management issue. Continue the checklist with emphasis of fuel related items that follow. If it doesn’t, then it is a computer or timing issue: see Step 4.

    Clue – listen for the fuel pump to prime when you first turn the ignition switch on. It should run for 5-20 seconds and shut off. To trick the fuel pump into running, find the EEC test connector and jump the connector in the Upper RH corner to ground. The EEC connector is near the wiper motor and LH hood hinge.
    [​IMG]

    If the relay & inertia switch are OK, you will have power to the pump. Check fuel pressure – remove the cap from the schrader valve behind the alternator and depress the core. Fuel should squirt out, catch it in a rag. Beware of fire hazard when you do this. In a pinch, you can use a tire pressure gauge to measure the fuel pressure. It may not be completely accurate, but you will have some clue as to how much pressure you have. If you have any doubts about having sufficient fuel flow/pressure, rent a fuel pressure test gauge from the auto parts store. That will tell you for sure if you have adequate fuel pressure.


    4.) No fuel pressure, possible failed items in order of their probability:
    A.) Tripped inertia switch – Coupe & hatch cars hide it under the plastic trim covering the driver's side taillight. Use the voltmeter or test light to make sure you have power to both sides of the switch
    B.) Fuel pump power relay – located under the driver’s seat in most stangs built before 92. On 92 and later model cars it is located below the Mass Air Flow meter. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
    C.) Clogged fuel filter
    D.) Failed fuel pump
    E.) 86-90 models only: Blown fuse link in wiring harness. Look for 12 volts at the Orange/Lt Blue wire on the fuel pump relay.
    91-93 models only Blown fuse link in wiring harness. Look for 12 volts at the Pink/Black wire on the fuel pump relay.
    The fuse links for all model years 86-93 live in the wiring harness near the starter solenoid.
    94-95 models only: 20 amp fuel pump fuse in the engine compartment fuse box. Look for 12 volts at the Dark green/yellow wire on the constant control relay module.
    F.) Engine seem to load up on fuel and may have black smoke at the tailpipe. Fuel pressure regulator failed. Remove the vacuum line from the regulator and inspect for fuel escaping while the pump is running. If fuel is coming out the vacuum port, the regulator has failed. Check the regulator vacuum line for fuel too. Disconnect it from the engine and blow air though it. If you find gas, the regulator has failed.

    5.) Fuel pressure OK, the injectors are not firing.
    A.) A noid light available from any auto parts store, is one way to test the injector wiring.
    The noid light plugs into the fuel injector harness in place of any easily accessible injector. Plug it in and it will flash if the injector is firing.
    B.) I like to use an old injector with compressed air applied to the injector where the fuel rail would normally connect. I hook the whole thing up, apply compressed air to the injector and stick it in a paper cup of soapy water. When the engine cranks with the ignition switch on, if the injector fires, it makes bubbles. Cheap if you have the stuff laying around, and works good too.
    D.) Pull an injector wire connector off and look for 12 volts on the red wire when the ignition switch is on.
    E.) No power, then look for problems with the 10 pin connecter (salt & pepper shakers at the rear of the upper manifold).
    F.) No power and the 10 pin connections are good: look for broken wiring between the orange/black wire on the ECC relay and the red wire for the 10 pin connectors.
    G.) TPS voltage exceeds 3.7 volts with the throttle closed. This will shut off the injectors, since the computer uses this strategy to clear a flooded engine. Use a DVM, a pair of safety pins, and probe the black/white and green wires to measure the TPS voltage.
    On a 94-95 Mustang, probe the black/white and grey/white wires to measure the TPS voltage.
    It should be .5-.99 volts with the key on, engine not running. Note that if the black/white wire (signal ground) has a bad connection, you will get some strange readings. Make a second measurement using the battery post as the ground to eliminate any ground problems. If the readings are different by more than 5%, you may have a high resistance condition in the black/white signal ground circuit.

    6.) Spark & fuel pressure OK.
    A.) Failed IAB (no airflow to start engine). Press the throttle ¼ way down and try to start the car.
    B.) Failed computer (not very likely)
    C.) Engine ignition or cam timing off: only likely if the engine has been worked on recently).
    D.) Firing order off: HO & 351 use a different firing order from the non HO engines.
    HO & 351W 1-3-7-2-6-5-4-8
    Non HO 1-5-4-2-6-3-7-8
    E.) No start when hot - Press the throttle to the floor & try starting it if you get this far. If it starts, replace the ECT.


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  3. harveybbc

    harveybbc New Member

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    msd no spark

    I messed around with it some more last night and now i get a dull spark at the wire.If i cross the plug wires i get a back fire,im thinking of getting another distributor.Im getting gas for sure my plugs keep getting soaked and i have to remove them and clean them.

    Maybe my pip is gone?if so wold it create a small spark?I noticed the metal wheel in the bottom of the distributor had rubbed the pip at some point i can see some of it on the wheel .I checked the coil works great installed another just in case with same results.When i turn it over spins with no sign of it starting unless i cross a plug wire. :(
  4. harveybbc

    harveybbc New Member

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    Also wanted to ad i can not get my timing light to flash when it is connected to the wire im thinking its because of the weak spark.
  5. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    Remove the SPOUT connector and try starting the engine. If it starts good then, replace the PIP sensor or distributor.
  6. harveybbc

    harveybbc New Member

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    I am unsure where the spout connector is .
  7. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    It is located in the distributor wring harness that connects to the TFI. It is a small square jumper plug that you remove to set ignition timing and reinstall when you have finished setting the timing.

    See item #41 on the drawing below.

    Diagram courtesy of Tmoss & Stang&2birds
    [​IMG]

    See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/

    Ignition switch wiring
    http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

    Fuel pump, alternator, ignition & A/C wiring
    http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

    Computer, actuator & sensor wiring
    http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

    Fuse panel layout
    http://www.veryuseful.com/mustang/tech/engine/images/MustangFuseBox.gif

    Vacuum routing
    http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg
  8. harveybbc

    harveybbc New Member

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    Pulled the spout connector and still nothing.I have good compression gas and extremely light spark.Do you think maybe a bad ground somewhere or?? i will try anything just throw me some ideas :) Thanks again for your time.
  9. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    See checklist step 1 G next.
  10. harveybbc

    harveybbc New Member

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    Hey i figured it out for some reason if i wire it as a non 5.0 ho it starts right up,So apparently someone put a non ho engine in here even tho it does hold a roller cam ??Thanks for all your help i guess im going to need to convert it to mass air flow because it idling a tad ruff and running rich.:lol:
  11. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    This doesn’t prove that the block is a HO block. Some trucks evidently use a HO firing order
    with a low lift cam. However, it will definitely prove that a block can’t be HO because the firing order is wrong.


    Remove the #1 & #3 spark plugs. Put your finger in #1 spark plug hole. Crank the engine over until you feel compression on #1 cylinder. Slowly turn the engine until the TDC mark and the timing pointer line up. Mark TDC on the balancer with chalk or paint. Put your finger in #3 spark plug hole and crank the engine 90 degrees. You should feel pressure trying to blow past your finger. If you do not feel pressure, repeat the process again. If you feel pressure, it is a HO engine.

    No pressure the second time, remove spark plug #5. Put your finger in #1 spark plug hole. Crank the engine over until you feel compression on #1 cylinder. Put your finger in #5 spark plug hole and crank the engine 90 degrees. If you feel pressure now, the engine is not a HO model, no matter what it says on the engine.

    Using a small carpenter or machinist square to mark the harmonic balancer off into 90 degree sections may be helpful here.

    A 15/16 deep socket & breaker bar or ratchet may be used to turn the engine.

    The HO firing order is 1-3-7-2-6-5-4-8.
    Non HO firing order is 1-5-4-2-6-3-7-8
    [​IMG]
  12. harveybbc

    harveybbc New Member

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    Ok i see one more question how much problems should this e303 cam cause me? Right now it is idling very ruff and burning very rich.I am going to remove the plugs and clean them again and double check the timing i can hear small pops in the exhaust.
  13. 90GT306

    90GT306 Founding Member

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    OK You have spark,
    First, I would convert to mass air when you change cams with a larger lift to help with idle. I don't think you mentioned anything about what size injectors your using. The poping sound is too much fuel. Nothing in your post strikes me to increase the injector size, if you did or didn't. Timing chain, is it adjustable or not, was it installed at o or advanced/retard. Is your pushrods the right length or the rockers bolted down properly. All these little things can play a role in the way your car runs.
  14. jrichker

    jrichker StangNet's favorite TOOL SN Certified Technician Founding Member

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    On a 5.0, the camshaft determines the firing order. IF you indeed have a real Ford E303 camshft, you have the HO firing order. However, some people will use a non HO firing order computer with a HO engine. This plays havoc with the fuel injection timing, since some of the injectors will squirt when the intake valve is closed. See http://fordfuelinjection.com/index.php?p=92 for more information.

    Go back, and check the firing order using the instructions I posted eariler. Then check the computer tag to verify the part number. See http://fordfuelinjection.com/?p=17 for help with finding the computer tag code and what tag numbers cross reference to what vehicle.

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