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Discussion Starter · #1 ·
I have a '94 Sable 3.8 engine 126k miles. It always cranks just fine. Sometimes it will fire up just fine and sometimes I have to crank it then stop and crank it again several times before it will fire. The first time it did this I sprayed a little starting fluid in the intake and it fired right up.After it starts it runs normal. The only thing I have done is to change the distributor cap and rotor,the one that was on there was really bad. Any suggestions?
Thanks
 

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When was the last time the fuel filter was changed? Do you hear the fuel pump run its 2 second prime cycle when turning key to run? Have you checked fuel pressure? Is the fuel pump the original? Listen to the IRCM when someone else turns the key to RUN. Do you hear the relay click on and then off 2 seconds later? Have you tried running the fuel pump with key in RUN via the EEC TEST connector?

If it isnt obvious, I am thinking a fuel problem.
 

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Where are you on All past & present due scheduled maintenance call outs????

Try cycling the ignition key from Off, to Run 4-5 times, pausing at run long enough for the fuel pump to cut off each time (about 2 seconds), Then go to Start, to have the starter motor crank the engine. If it'll immediately start & run, suspect a fuel delivery problem. So pull the fuel pressure regulator vacuum hose & inspect it inside to see if it's wet with fuel. If so, it's diaghpragm is leaking fuel, so replace the fuel pressure regulator.
If that checks out ok, do a KOEO, KOER fuel pressure check & a fuel rate/delivery over time test. If pressure, or delivery are low, maybe suspect the fuel filter if it's not been changed in the past 30K miles, as the scheduled maintenance calls out.
If the fuel filter is ok, maybe suspect the fuel pump. Could be weak/worn out, or maybe you have an under load voltage drop to it, so check it's operating voltage with your multimeter on the 20VDC range, it should have close to B+ voltage going to it when running.

You say that the dist cap & rotor were in bad shape, so what kind of shape are the plugs & wires in????? When were they last changed????

Some thoughts for consideration, let us know what you find.

EDIT: Dang I've gotta get a faster keyboard!!!!! lol
 

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Discussion Starter · #5 ·
I got a new fuel filter and some Autolite ap5145 platinum plugs. I'm going to install them tomorrow. The gap is to be set at .54. This seem a little big to me but everywhere I look it says this is the gap. Any thoughts?
Wires and air filter later. I'm on a budget.
 

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Is there a sticker (decal) with plug gap specs still affixed underhood? Any parts store clerk, haynes or chiltons repair manual can confirm. Dunno if plug gap info is in the owners manual? Or google it.
 

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Gap

I got a new fuel filter and some Autolite ap5145 platinum plugs. I'm going to install them tomorrow. The gap is to be set at .54. This seem a little big to me but everywhere I look it says this is the gap. Any thoughts?
Wires and air filter later. I'm on a budget.
That is correct. Well not really. It is 0.054" not 0.540". New plugs today are gapped more reliable than in the past. Platinum plugs have much smaller center electodes and can jump the larger gap compared to "back in the day" ones. If you should need to regap, be very careful to not touch the center electrode. It is only about .040" in diameter.

Air filter is normal maint. Plug wires are best not changed unless they are damaged. If you put on new ones, I would ohm each to be sure they are OK. New wires that are "open" do happen and it is a pain. You just assume that new is perfect.

-chart-
 

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I got a new fuel filter and some Autolite ap5145 platinum plugs. I'm going to install them tomorrow. The gap is to be set at .54. This seem a little big to me but everywhere I look it says this is the gap. Any thoughts?
Wires and air filter later. I'm on a budget.
Good idea to opt for the fine wire iridium enhanced platinum plugs imo, as they'll likely last a lot longer & the spark gap will stay in spec longer. I'm using them also on my 94 3.8L also. I've noticed faster starts.

Apply a light coating of Permatex nickel loaded high temp anti-sieze compound to the plug threads, don't get any on the ceramics or electrodes & torque the plugs to the Min side of spec.

Yes there is room to get a torque wrench on the 3.8L firewall bank spark plugs, if you'll remove the intake air tube, distributor cap & rotor, mount the engine with your knees atop the intake manafold, cushioned with a folded towell & go at the plugs from around the opening at the distributor. There is plenty of room back there for a 3/8 wratchet & Harbor Freight 1/4" drive torque wrench to swing & properly torque up the plugs. Set the torque value to the Min side of spec, to allow for the anti-sieze lube effect, so you don't over tighten them. BTW they have the 1/4 drive torque wrench on sale for $19!!!! They also have a 4 count pack of drive adapters, that'll allow you to adapt your 3/8 drive spark plug socket to the 1/4 drive torque wrench.
Some folks also remove the firewall plastic trim piece to aid access to the plugs & wires, but I was able to manage without removing mine, as the danged push pin fastners wouldn't let go & I didn't want to break any.

Lube the plug wire boots on both ends & the plugs external ceramic insulator with a light coating of good quality dielectric grease, like a GE, DowCorning, or Permatex/Loctite product, to help prevent flashover on those wet rainy days or those damp, dewey, fall morning starts. It'll also prevent the boots from sticking to the plug insulators, so they're easier to remove if you have to go in there again.

If you lube the distributor end spark plug wire & coil wire boots, you may have to slip something like a hair pin under the edge of the boot when installing, to burp the air out as you push it on, so trapped air won't act as an air spring & push the wire up/out when the engine warms up, as this will cause a hard to find miss.

I'd also consider spraying the distributor cap inside & out, with a good quality silicone product, as it'll also help prevent flashover on wet, dewey days.

I like chartmakers ideas to cautiously check/set the plug gap & yes 0.054" is the right gap, not .540", which is more than half an inch!!!!! lol
Use a Wire Gauge type tool to slowly ease up on & check the proper spark gap, Don't force the tool between the gap, so as not to damage the finewire center electrode, or platinum pad on the ground sidewire.
My Motorcraft finewire plugs weren't anywhere near the right gap, right out of the box, so check all of yours before installing.
I also like his suggestion to check the plug wires end to end continuity & resistance.
Wiggle them on both ends when testing, the ohm reading should be steady at about 1000 ohms/inch of length, 30,000 ohms Max, no matter the length. I've heard of bad, or NO plug wire connections at either end, right out of the box, so check your wires before installing them.

A bunch more thoughts for consideration, let us know how it goes.
 

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Discussion Starter · #9 ·
Still having a start problem. I have changed the cap-rotor-plugs-wires-fuel filter.
After all that it took a few seconds longer to start. I figured the fuel had to fill the new filter. after it started I restarted several times and it was fine. I took it for a ride and it had more power then before.
So it sat all day in 100 degree weather in the sun and would not start :angry:. I sprayed some starting fluid down the intake and it fired right up. Shut it off and it started just fine a couple of times. I always thought if it started with starting fluid it was a spark problem. If it did not start with starting fluid it was a fuel problem. I have no tools to do any testing.I pulled the vacuum line off the fuel regulator and no fuel dripped out. I hate to change it on a guess as it is $50.00.
Anything else I can look at?
 

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Fuel in the fuel pressure regulator vacuum line, suggests that the regulators diaphragm is ruptured, so the fuel pressure regulator should be replaced.
 

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Discussion Starter · #11 ·
Fuel in the fuel pressure regulator vacuum line, suggests that the regulators diaphragm is ruptured, so the fuel pressure regulator should be replaced.
There was no fuel in the regulator vacuum line. So just now I started it four times in a row with no problems.
Does it make any sense to disconnect the battery for a while and let the computer reset? I know once in a while problems are very hard to diagnose.
 

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WOOPS, I mis-read your other post, after re-reading it I see you said it had NO fuel in the vacuum line, thats good!!!!

If you have/suspect a weak fuel pump, after it sets for a while & won't start, try cycling the ignition switch from Off to Run 4-5 times, Then go to start & crank the engine & see if it'll run without delay, if it does suspect a weak fuel pump.
So have a KOEO, KOER fuel pressure test done at the under hood fuel rail schrader valve test port, with the pressure regulators vacuum line on & off the regulator with the engine running. PSI at KOEO vacuum line attached, should be around 40 psi. KOER vacuum line attached a min of 28psi, but usually runs 30-35 psi. KOER vacuum line dis-connected & plugged, 40 psi.

Disconnecting the battery wipes the computers KAM & any stored trouble codes & the computer will need to relearn it's cold & warm idle routine to prevent idle & driveablity problems & to begin to build new fuel trim tables.
 

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Discussion Starter · #13 ·
The car still would not start all the time after all I did. So after much research on the net I was led to replacing the idle air controller. This solved the starting problem but the idle was all over the place and sometimes it would just die. then I remebered that one of my customers was a master mechanic. He went to the Ford school for the 3.8 engine. He said maybe I got a bad IAC but before taking it back I should remove both battery cables and touch them together to clear everything out. I did this and so far the idle has been fine.
 

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Discussion Starter · #14 ·
The car has been starting just fine since my last post until today.
Would the fact that it had just under a 1/4 tank of gas and it's parked with front end on a downward angle prevent the pump from working ? It started after several squirts of starting fluid was sprayed in the air intake. After it starts this way I can shut it off and restart it several times in a row. I went and filled the tank and we will see if it starts right up in the morning.
 

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What happens when you cycle the ignition switch from off to run several times, before going to the start position to crank the engine, when it's in one of it's no start fits????

It's probably time to do a proper fuel pressure & pressure bleed down check with a pressure gauge connected to the fuel rail schrader valve.
 

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Have you tried cleaning the MAF sensor? Just a thought, since mine got dirty on a trip across Missouri this summer and had similar symptoms. Turned out to be a rich fuel condition code caused by some gunk that got on there after I changed the air filter.
 

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Discussion Starter · #18 ·
Have you tried cleaning the MAF sensor? Just a thought, since mine got dirty on a trip across Missouri this summer and had similar symptoms. Turned out to be a rich fuel condition code caused by some gunk that got on there after I changed the air filter.
The exhaust does smell a little heavy on the unburned fuel side. I did clean it about a year ago. I'll give that a try.
 

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Discussion Starter · #19 ·
We are now going to fill the tank when it gets down to 1/2 full to see if the car will always start when parked on a slight incline. Also here in Denver we are going to go into the cold to bitter cold time of the year. I wonder if this weather will affect the starting.
 

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Discussion Starter · #20 · (Edited)
I finally got fed up with the once in awhile no start issue. Today I installed a new fuel pump.
So far it has started 5 times with no problem and two other issues have gone away.
It now starts and the idle does not surge up and down.
When put in gear it does not try to surge forward,the idle just stays low like it should.
So besides the new fuel pump it has new -plugs-wires-distributor cap- rotor-fuel filter-IAC.
Have I missed anything? Forgot it also got a new radiator and thermostat last summer.
 
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