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  1. #1
    Senior Member douglap1's Avatar
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    Default Zetec starting sequence

    In order to start my Zetec engine, I always have to turn on the ignition switch before turning on the master switch, which then runs the fuel pump for a few seconds and pressurizes the fuel rail. The engine will then fire-up easily and run fine.

    The problem is that if I'm belted in the car (say after a black flagged session), I can't reach the master switch to cycle the system and pressurize the fuel rail. Then starting is almost impossible.

    In searching this forum, I find from other threads that these systems do normally bleed fuel pressure down soon after the engine is shut down. I have a fuel pressure read out on the dash, and can see it bleed down pretty quickly after a minute or two.

    So, I really need some way to cause the fuel pump to run and re-pressurize the fuel rail without having to cycle the master switch. Does anyone have a good solution for this?

    Thanks for any info.

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    Classifieds Super License BeerBudgetRacing's Avatar
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    The fuel pump shouldn't be energized by the master switch.

    It should be energized when you turn on the ignition switch.

    That said there are times when cycling the master is needed - like it's getting worn.

    There should also be a pump-on push button in the engine compartment.
    I've always thought that should be repeated on the dash.

  3. #3
    Senior Member douglap1's Avatar
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    Quote Originally Posted by BeerBudgetRacing View Post
    The fuel pump shouldn't be energized by the master switch.

    It should be energized when you turn on the ignition switch.

    That said there are times when cycling the master is needed - like it's getting worn.

    There should also be a pump-on push button in the engine compartment.
    I've always thought that should be repeated on the dash.
    Thanks for the response. To clarify: If my master switch is turned on and then the ignition switch is turned on, the fuel pump never runs. The only way to run the fuel pump is to turn the ignition switch on first, and then turn the master switch on. Perhaps there is something wired incorrectly in my car.

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    Contributing Member DaveW's Avatar
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    Quote Originally Posted by douglap1 View Post
    Thanks for the response. To clarify: If my master switch is turned on and then the ignition switch is turned on, the fuel pump never runs. The only way to run the fuel pump is to turn the ignition switch on first, and then turn the master switch on. Perhaps there is something wired incorrectly in my car.
    Basically, that's the way mine works. However, I don't ever turn off the ignition switch except to crank the engine w/o activating the injectors to oil it down, etc.

    If you switch on the ignition IMMEDIATELY after the master, you will get 1 priming cycle. But that's a PITA. So to get the 3 or more primes (necessary to start my Zetec) it's much easier to cycle the master. I listen for the fuel pump each time and don't turn the master off each time until it stops by itself.
    Dave Weitzenhof

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    Classifieds Super License BeerBudgetRacing's Avatar
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    Isn't the pump controlled by the ECU ?

    Do you both have a 'pump-run' button?

    I believe my ignition switch turns on the ECU which then runs the prime cycle when the ECU starts up.

    Maybe mine is wrong - but I've never had a problem starting unless the pump is bad.

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    Contributing Member EYERACE's Avatar
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    anticipating the time frame from black to green by watching how grid workers are talking/listening to their radios.......ask a grid worker ahead of time to come over and switch on the master when you signal to them.

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    Default Why does engine need more than 1 prime cycle?

    Quote Originally Posted by DaveW View Post
    So to get the 3 or more primes (necessary to start my Zetec) it's much easier to cycle the master.
    I know of several Zetec drivers that also conduct multiple master cycles to get the engine to fire.

    Assuming none of the fuel lines have air in them, I don't understand why one prime cycle of the pump doesn't get the fuel rail up to full regulated system pressure. Next time we're in the race shop, I want to conduct a little test in which I watch the live fuel rail pressure while conducting multiple prime cycles on an engine that hasn't been fired two weeks.

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  9. #8
    Contributing Member DaveW's Avatar
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    Quote Originally Posted by Jon Jeffords View Post
    I know of several Zetec drivers that also conduct multiple master cycles to get the engine to fire.

    Assuming none of the fuel lines have air in them, I don't understand why one prime cycle of the pump doesn't get the fuel rail up to full regulated system pressure. Next time we're in the race shop, I want to conduct a little test in which I watch the live fuel rail pressure while conducting multiple prime cycles on an engine that hasn't been fired two weeks.
    IMO, the reason we need multiple prime cycles is that we need to get a rich A-F mixture (like a choke would do on a carburetor) all the way into the combustion chambers especially with the Pectel T2 ECU. And on my Zetec, the idle is pretty fast, so it needs a lot of fuel to do that. I don't think the issue is air/vapor or low pressure in the fuel lines.

    It's sorta like the old tractor (1922 IH 8-16) we used to have on the farm - it had a petcock on each cylinder that you squirted gas into and then closed before hand cranking it. I have a lot of stories about that old beast.
    Last edited by DaveW; 07.10.24 at 3:33 PM.
    Dave Weitzenhof

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    Classifieds Super License BeerBudgetRacing's Avatar
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    Quote Originally Posted by DaveW View Post
    It's sorta like the old tractor (1922 IH 8-16) we used to have on the farm - it had a petcock on each cylinder that you squirted gas into and then closed before hand cranking it. I have a lot of stories about that old beast.
    Had a International TD6. Hand crank start on gas and once it was running good and the cyl warm you'd switch it to diesel.

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    Contributing Member DaveW's Avatar
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    Quote Originally Posted by BeerBudgetRacing View Post
    Had a International TD6. Hand crank start on gas and once it was running good and the cyl warm you'd switch it to diesel.
    Same thing on our old IH - start on gas (small tank) and switch to kerosene (large tank) once it was running. Had to have the timing and throttle setting just right or it either wouldn't start or it would kick back on the crank. Lots of folks injured their thumbs holding the crank wrong. Also had to hold the magneto retard to get spark while cranking.
    Dave Weitzenhof

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    Senior Member John LaRue's Avatar
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    Quote Originally Posted by douglap1 View Post
    In order to start my Zetec engine, I always have to turn on the ignition switch before turning on the master switch, which then runs the fuel pump for a few seconds and pressurizes the fuel rail. The engine will then fire-up easily and run fine.

    The problem is that if I'm belted in the car (say after a black flagged session), I can't reach the master switch to cycle the system and pressurize the fuel rail. Then starting is almost impossible.

    In searching this forum, I find from other threads that these systems do normally bleed fuel pressure down soon after the engine is shut down. I have a fuel pressure read out on the dash, and can see it bleed down pretty quickly after a minute or two.

    So, I really need some way to cause the fuel pump to run and re-pressurize the fuel rail without having to cycle the master switch. Does anyone have a good solution for this?

    Thanks for any info.

    Most of the harnesses have a "Pump Out" switch located at or near the roll hoop. You could possibly extend that and place a switch on the dash which will over ride the ECU. My car is wired such that the master is on the dash and is activated from the roll hoop by a pull wire.

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    Contributing Member DaveW's Avatar
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    Quote Originally Posted by John LaRue View Post
    Most of the harnesses have a "Pump Out" switch located at or near the roll hoop. You could possibly extend that and place a switch on the dash which will over ride the ECU. My car is wired such that the master is on the dash and is activated from the roll hoop by a pull wire.
    I'd be afraid of flooding attempting to prime that way. The good thing about the method I mentioned is that there is a fixed prime length each time you do it, so priming the "correct" amount is much easier to monitor.
    Dave Weitzenhof

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    Check the fuel pressure regulator and make sure it holds pressure after cycling the master with ignition on ,It should stay steady at about 52-55 psi.If it’s not holding pressure,replace diaphragm
    Hope this helps
    Tim
    Tim Minor

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    It's pretty simple- when cold, cycle the master switch once or twice (listen to make sure the fuel pump pressurizes the fuel rail). It should start right up. If not, rinse and repeat. The ECU is looking for minimum 300 rpm from the crank sensor before it activates the spark, so make sure the jump battery is good enough. Always use a jump battery unless you have a very large Li battery installed.
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    In memory of Joe Stimola and Glenn Phillips

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    Senior Member douglap1's Avatar
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    Default Thanks guys - I'll move the Master now

    Thanks for all the info guys. I was hoping there was a relay hidden somewhere that was wired wrong, but it sounds like it is normal for the ECU to only run the pump and prime the motor when the main power is switched on with the ignition on. I'm thinking the best solution is to move the master switch so that I can reach it while belted in the car.

    For the record, there does not seem to be anything wrong with my pump or pressure regulator. The fuel rail pressure goes immediately to about 60 psi when the pump runs for priming, but the pressure bleeds down to about 30 psi after 3 minutes, at which point it becomes hard to fire it off. However, if I start the motor immediately after priming, everything runs great.

    Yes, I have asked the track officials to cycle my master switch at the end of a black flag session, which has caused some confusion with some grid workers who questioned if they were allowed to do that. As usual, the best solution is to be able to do it yourself.

    Thanks again guys,

    Paul Douglas

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    Contributing Member Lotus7's Avatar
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    If the initial pump priming cycle generates the required rail pressure, then stops automatically (as we all hear), and the pump is in good enough condition to maintain that pressure while flowing, please explain to me what the second and subsequent pre-start priming cycles are actually doing, (and what changes between each cycle), that isn't accomplished by the first one?
    thanks
    Ian Macpherson
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    Contributing Member DaveW's Avatar
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    Quote Originally Posted by Lotus7 View Post
    If the initial pump priming cycle generates the required rail pressure, then stops automatically (as we all hear), and the pump is in good enough condition to maintain that pressure while flowing, please explain to me what the second and subsequent pre-start priming cycles are actually doing, (and what changes between each cycle), that isn't accomplished by the first one?
    thanks
    As I said in one of my previous posts, it's just adding more fuel into the intake to be sucked into the combustion chamber as a richer mixture when you try to start it.
    Dave Weitzenhof

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    Classifieds Super License BeerBudgetRacing's Avatar
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    Quote Originally Posted by Lotus7 View Post
    If the initial pump priming cycle generates the required rail pressure, then stops automatically (as we all hear), and the pump is in good enough condition to maintain that pressure while flowing, please explain to me what the second and subsequent pre-start priming cycles are actually doing, (and what changes between each cycle), that isn't accomplished by the first one?
    thanks
    It is my understanding that the priming cycle not only builds pressure in the rail, it squirts fuel through the injectors.
    Therefore, the more cycles you do the more fuel is in the intake.

    I personally have not had that issue and can generally start first try. The only time I had trouble starting was when my fuel pump was going bad.

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    Contributing Member Lotus7's Avatar
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    Quote Originally Posted by DaveW View Post
    As I said in one of my previous posts, it's just adding more fuel into the intake to be sucked into the combustion chamber as a richer mixture when you try to start it.
    ah, so you're saying the injectors are firing fuel into the cylinders during the prime cycle? I thought all that was happening was that the rail was being pressurized; makes more sense now. thanks

    edit: as a follow up curiosity, I wonder why the race zetec prefers to have a different starting procedure than the millions of road cars that used this same engine?
    Ian Macpherson
    Savannah, GA
    Race prep, support, and engineering.

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    Classifieds Super License BeerBudgetRacing's Avatar
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    Quote Originally Posted by Lotus7 View Post
    ah, so you're saying the injectors are firing fuel into the cylinders during the prime cycle? I thought all that was happening was that the rail was being pressurized; makes more sense now. thanks

    edit: as a follow up curiosity, I wonder why the race zetec prefers to have a different starting procedure than the millions of road cars that used this same engine?
    Different ECU. Different FI system.

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    Contributing Member DaveW's Avatar
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    Quote Originally Posted by BeerBudgetRacing View Post
    Different ECU. Different FI system.
    If the Pectel T2 ECU had a properly rich during startup map setting programmed in, we maybe wouldn't need to prime it.
    Dave Weitzenhof

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  29. #22
    Senior Member douglap1's Avatar
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    Quote Originally Posted by Lotus7 View Post
    ah, so you're saying the injectors are firing fuel into the cylinders during the prime cycle? I thought all that was happening was that the rail was being pressurized; makes more sense now. thanks

    edit: as a follow up curiosity, I wonder why the race zetec prefers to have a different starting procedure than the millions of road cars that used this same engine?
    Ian:

    When we are racing in Savannah in July, mine only needs one priming in the morning to fire right up, but at the first race of the season in February, I need 3 primes in the morning to get it fired up.

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    Contributing Member DaveW's Avatar
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    Quote Originally Posted by douglap1 View Post
    Ian:

    When we are racing in Savannah in July, mine only needs one priming in the morning to fire right up, but at the first race of the season in February, I need 3 primes in the morning to get it fired up.
    Similar here - depends on the ambient and engine temperature.
    Dave Weitzenhof

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