Jittering engine when it is warm

Well as I expected because of feedback from 2 ford dealers and a couple mechanics an issue like mine will be difficult to pinpoint.
Fuel filter is now new. The old one was not clogged but due for a change.
Car stiil stalls at idle.
What they noticed is that if you restart the car without bringing the key all the way back to its normal position when you shut the car off, well the car won’t crank. It wants to start but won’t crank the engine, kind of like the starter is going bad.

Test to starter is negative.
Ignition system tests negative.
Fuel pressure test is good.
Tests to determine if wires are grounded properly or show deficiency so far are negative.
Hall effect sensor test is negative.
Main computer was tested, that’s negative.
Temperature sensors were checked and that’s negative.
They are still suspecting something to do with the ignition system.

To see if it would have anything to do with the stalling, I thought I would tell them that in July 2014, the AC would not get cold.
My radiator guy glanced over the possible areas the freon would have leaked from. Nothing was obvious and he recharged the AC with the R-134a freon and put I think an adapter were he recharged from and the cap.
AC was tested and all was good.

Since the leak of the old freon was not identified could it be at all related to the hesitation and stalling issue now? Althoug, the car didn’t hesitate or stall when the old freon disappear.

I’m frustrated that they may give up ad soon as tomorrow on searching for the source of the problem .
Time is money and I’m at a bunch already.
It rides so nicely. The praised Americana car ride. So bummed.

The temp sensors were fine, good, did they check the running temp of the car? does to still run good at high speed and lack heat from the heater?

OP writes …

you try to restart the car without bringing the key back to it’s off position it won’t crank. It tries to start but no cranking. Bring the key back to total off position and start, it cranks then it stalls within 2 to 3mns.

A little confusing. Especially that is tries to start but no cranking.

“Cranking” means the engine makes that "rrrr rrrr rrrr " sound when you turn the key to “start”. Usually “cranking” is following by the engine catching, it starts, and continues to run.

Maybe explain what yours does in comparison.

GeorgeSanJose by cranking I mean the engine will run so I could drive it.

Barkydog, I will need to confirm that they’ve checked what you are suggesting. I don’t beleive they’ve driven it out at high speed. They might have revved it at high rpm in the bay. I will need to find out.
What would you consider high speed and for how long?

Hmm, I think I forgot to mention that on oct 24 when I revved up the car at steady rpm for almost 10mns and I almost had my foot off the gas peddle, vapors came out from underneath engine in the back of the block on driver’s side. I couldn’t recognize the smell of neither motor oil, transmission nor antifreeze. Talked to my husband about it and he said not to panick it may be the fuel cleaner burnig off and escaping from the intake manifold. Hmm!
The shop mentioned no sign of that so far while testing.

By control module do you mean the ignition control module mounted on the distributor?

You state the ignition timing was adjusted. This car should be a TFI model so do you know if the SPOUT connector was disconnected during this operation?
If not, the timing will be nowhere near correct.

The complaint points in several directions so I’m trying to think this out.

The one part about the key and restarting could point to a failed ignition switch; meaning the electrical part. These can fail over time due to the heater blower motor. The current for the blower goes directly through the switch and a worn blower is a high current consumer of electricity. That can overheat the switch and even melt it.

1986 Lincoln Continental 5L 93800.

Recently I posted the initial issue with my car; Jittering engine when it’s warm.
If you wish you can check it out before addressing this one.
However now the car is at the shop.

In the discussion I shared that it seem to hesitate/jitter when it ‘s warm after 20 miles or so, then it began sooner, then it began stalling at idle. The story is on my first post.

The car’s was towed to the shop Monday.
The car stalled for them like it did for me.
One thing they noticed is that after it stalls and you try to restart the car without bringing the key back to it’s off position it won’t start the engine.
It tries to start just but won’t actually start the engine. It sounds like you have a bad starter or may have flooded the carburator which this car does not have.
Bring the key back to total off position and start, the engine starts no problem, then it stalls within 2 to 3mns.
They suspect an ignition issue.

Before they began any testing I requested they change the fuel filter which was way overdue.
The old one was not clogged.
Hesitation is not due to a clogged filter.

Service and Parts done and changed in Oct 2015 before towing and problem occurrences are listed in the order they were done / happened:
10/6 - Tire pressure, balancing and rotation
10/7 - Motor Oil and filter
10/8 - 1st Smog Check failed – Needs timing adjustment
10/10 - Motor on 2 doors fixed – killed battery – recharged – cranked
10/12 - Drove car about 40 miles before appointment to adjust timing and 2nd Smog Test – Car
Hesitates strongly at off Ramp. Must fix problem before re-smog
10/17 -Tune Up done – New plugs, wires, distributor cap, rotor – tested 5 miles only – no hesitation
10/19 – Drove car about 15 miles before appointment at Smog Shop – New Control Module (cracked
fell apart), 1 new vacuum hose, timing adjusted.
Passed the Smog Test
Subtle hesitation resumes when leaving Smog Shop. Mechanic doesn’t know why.
10/21 - Subtle hesitation within 6 miles (sooner then before).
Added 15oz can of Total Berryman + fueled up.
Hesitation significant especially on slight upward grade (am in hilly area)
1st stall at low idle when pulling out of store parking lot. Cranks back up
Once home, left idling, stalled within 2 to 3mns. Stopped trying after 3 times
10/22 - Car stalled at beginning of drive up of driveway with a 40% grade.
Back in car port, idle, stall. Stopped trying after 3 times.
10/24 – Cranked car, slight hesitation noted, revved up slightly for a few minutes. Decelerated slowly,
car began hesitating, foot off gas paddle, stall.
10/26 – Towed to shop.
Car stalls for them and they notice is that after it stalls and you try to restart the car without
bringing the key back to it’s off position, the engine won’t start.

Since at the shop using up to date testing equipment, own visual observation and listening, diagnostic diagrams, these following tests have come back negative:
Fuel pressure shows normal
Electrical wiring in engine test good for being grounded and performing
Hall effect sensor
Temperature sensors
Vacuum hoses
Main computer in dash board
Even ignition
These are the tests I’ve retained they conducted. They’ve looked at more than that.

At one point at testing, the car stayed cranked and ran for more than 5mns before stalling.
They then focused on temperature issue.
But the key position issue described early is still present.

So Temperature issue or Ignition or something else that has an effect on both?

In order to save me any more expenses which have added up, they’d really like to find the problem through testing before taking apart anything, however they might throw the towel in sooner than I’d like. My problem cannot take precedent over other newer cars with issues easier to detect with their equipment.
It’s an old car that’s otherwise in good general shape.

Ok4450, the Tech/Owner of the smog shop verified that the car is a TF1 model and that the SPOUT Connector was disconnected to adjust the timing. The smog report shows it at 10.

Oh and I’ve been told that the Control Module is another word for Ignition Module and is mounted near the Distributor.

What checks do you do for what you describe in your description about the ignition?

Could this heater blower issue also cause hesitation and stalling if wire connections there are faulty?

I believe I shared some info on air temp in car (not from AC) on oct 12 in my other post (car jittering and stalling) and recharge of AC in july 2014 without the source of the possible leak being identified.

Barkydog, they report the car runs warm at normal temp idling or revved up.

Regarding the New Control/Ignition module, the shop tested each the sensors and found that one was not putting out the proper signal to the coil.
He confirmed that although the smog shop installed a high grade module, 1 sensor failed.
In contacting a long time Ford mechanic colleague, he found out that all new ignition modules for this car are after market and many have manufacturing defectss and may have a short life.

So a new high grade module was installed,.All sensors passed the test. When the car stalled, they could restart it without bringing the key back to its complete off position.
They will continue to monitor it while they try to solve the stalling issue.

As FYI, unless you all know this already, the shop got 2 new high grade modules just in case and noticed that they and the new one that I had on all came from the same maufacturer but packaged differently.

About the stalling: using a lab scope, they are going to check the performance of the idle air control valve, watch the patern it gives and hopefully be able to determine the reason for the stall, which could lead to misfiring in the coil(s) or temp sensors.

Barkydog, my bad, they haven’t checked the temp sensors yet.

Missing due to intermittent in the ignition system combined with improper idle rpm control could cause most of these symptoms, so it sounds like your shop is on the right track. It seems likes there may be a problem in the ignition switch too, but if they have a lab scope they should be able to figure that out straight away. When I’ve had ignition switch problems I’ve been able to bypass the switch with my own home-brew switch just to prove that’s the problem. It’s a definitive test and it doesn’t take much effort.

Update.
Shop is now 99% sure that the distributor is the culprit. He explained why he was confident of his diagnosis and how the distributor’s malfunction causes the hesitation and the stalls at idle.
They’ll be installing a new Spectra Premium distributor Mon.
Yeap it’s going to cost.
The unit will cost me 297% more than a new one of the same make available on partsgeek.com.
As you know warranties between supplier and shop and overhead all play a part in this unless I do the job myself which I’m incapable of, let alone being able to diagnose the problem, and they have a 24000 miles/24 months parts and labor guarantee to customers.
I’m crossing my fingers that it won’t hesitate cold or warm and that it won’t stall at idle when they test it again and when I get to drive it again.