ROBUST CRANKING BUT DOESN'T START

[JIMLOG22]

I recently purchased a 1984 Mark VII LSC from a guy here in Toronto Canada. I started the engine and ran it for a half hour or so, then shut it off to pour in 15 liters of gas. Then I drove it about 100' to get to my parking spot in the garage. Now it will crank very nicely with the new battery but it will not start. Can anyone identify with this issue? JIM IN TORONTO

 

[Action]

Spray starter fluid or a flammable into the throttle body. If there is any kind of engine firing the issue is fuel.

If nothing the issue is ignition, or basic engine function.

How many miles on engine?
When you drove it to parking spot, did is stall and not restart?
Or just not restart on next use?
When & why was a new battery installed?

Action

 

[JIMLOG22]

Spray starter fluid or a flammable into the throttle body. If there is any kind of engine firing the issue is fuel.

If nothing the issue is ignition, or basic engine function.

How many miles on engine?
When you drove it to parking spot, did is stall and not restart?
Or just not restart on next use?
When & why was a new battery installed?

Action

I had an issue when I arrived at my address. The driver's rear air bag was down and when I started the car a few minutes went by before the suspension was fully inflated. When I drove down the ramp to the garage area, the engine ran rough but I managed to park it ok. I poured 5 gallons of hi test gas into the gas tank along with a small amount into the throttle body.

Subsequent attempts to start produced an small explosion out of the carbeurator- PUUUUFFFF some grey to black smoke came from the carbeurator. After that I installed a new battery and to this day, I have robust cranking but it will not start. The engine was rebuilt in 2020.
Thanks for your reply.
JAMES

 

[Action]

You had some fire with the ignition the fuel system is suspect.

Checking fuel pressure at the fuel rail while cranking would be the next step.
The fuel injector requires 20 PSI at minimum. Ideally should be nearly 30 PSI.

Other questions would be -
Has this vehicle sat for long periods of time?
Has the fuel filter been replaced regularly? (Is this a well maintained vehicle)

Not sure why you mentioned the suspension. This has nothing to do with engine controls.

Action

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[JIMLOG22]

Hello Action,
I've been sick and I am continuing to troubleshoot the presence of fuel in the Fuel Injection lines.
Also the fuel pump fuse could be an issue but I do not see where it should be on the fuse block.
Still have robust cranking.

 

[Action]

The fuel pump may not have a fuse. Circuit protection may be a fusible link.

Can you hear the fuel pump when someone turns the key on?
Is the inertia switch tripped?
What about the questions in post #4?


Action

 

[JIMLOG22]

The fuel pump may not have a fuse. Circuit protection may be a fusible link.

Can you hear the fuel pump when someone turns the key on?
Is the inertia switch tripped?
What about the questions in post #4?


Action

Other questions would be -
Has this vehicle sat for long periods of time?
Has the fuel filter been replaced regularly? (Is this a well maintained vehicle)

Yes I suspect it sat in an enclosed garage for some time maybe many months.
The owner p[assed away two years ago and the daughter was the seller.
I want to drive the Lincoln to my mechanic here in Toronto for the safety certificate.
I cannot hear the fuel pump at all.
JIM

 

[Action]

I cannot hear the fuel pump at all.
JIM

Check the inertia switch to see if it is tripped.
And you may not hear the fuel pump if there is enough pressure in the system.

After checking the inertia switch. And a little risky and there is an alternative way to check for fuel pressure at the fuel injectors.
(You have not stated and I am assuming you do not have a pressure gauge)
There is a Schrader valve on the fuel rail. The fuel rail feeds all of the fuel injectors.
Turn the ignition switch to on. (Don't crank the engine)
With a rag to contain spray, use something to depress the Schrader valve. When you do that, fuel should spray out in a good amount.

If fuel sprays out at least you know the pump works to some degree.
If no fuel sprays out there is an issue,

That issue will require a volt meter or test light to diagnose. Plus a wiring diagram. I have not found a fuel system wiring diagram on the net that will allow me to copy and paste. There are a couple of wiring diagrams (or EVTM) listed on eBay.

Action

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[driller]

An old hot rod saying...

Fuel, Air, Spark

Notice that Fuel is first.

As @Action has stated, you need to test for fuel pressure or confirm fuel pressure at the schrader valve on the fuel rail.

Following down the Fuel path. that would be to ascertain the fuel injectors are firing as you can have conditions which would lead to no fuel even though you have fuel pressure.

 

[JIMLOG22]

Hi Action,
I checked for the location of the fuel pump on line before I look for the filter and the inertia switch.
Is there a way around this?

https://lincolnmarkviiparts.com/wp-content/uploads/2024/03/fuelPumpAccessCover.pdf

JIM

 

[Action]

I am not sure how to answer the question of getting around something. (unknown)

As to the VID, there are risks. Risks of cutting something other than the floor pan.
Then there is the matter of resealing the floor without future leaks (dust) or squeaks.
I would recommend dropping the tank to replace the fuel pump. The addition benefit is to inspect the bottom of the tank for debris. If so to remove that.

Is the inertia tripped?
Has the fuel filter been replaced recently?

Action

 

[JIMLOG22]

An associate and I will replace the in-line fuel filter first to see if that will solve the fuel starvation issue.
I will also check the inertia switch now that I know where it is.
I have a 3 ton jack and two jack stands.
It looks we have a recently-installed gas tank on this Lincoln and it looks like the previous owner replaced the fuel pump, as well.
JIM

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[JIMLOG22]

The update is we replaced the fuel filter located just ahead of the pass side real wheel.
There is another furl filter side by side and we don't know why there are two .
What I thought is the inertia switch is something else- a relay or something in the trunk driver's side.
There is a lot of wiring in that area along with the suspension shut-off switch.
Today, Monday June 02, we will remove a spark plug and insert a sheet of paper on top of the cylinder to see if it gets wet with gas.
They say there is a schrader valve up near the carburetor to check for fuel pressure but I can't find the schrader valve.
JIM

 

[Action]

Your Mark does not have a carburetor.

A Schrader valve is to test fuel pressure in a fuel injection system.
All non-H.O. 5.0 Liter engines from 1983 to 1985 (including your Mark) have throttle body fuel injection. Not to be confused with sequential multi-port fuel injection.
There are two injectors in the throttle body of your 302. The Schrader valve is there as well.

Since your Mark has air suspension, there is a on/off switch in the trunk for the system.
The inertia is likely behind the passenger kick panel
The OWNERS manual will have the location and operation of both. It is a good read.

Action

 

[JIMLOG22]

Hi Action,
I took a picture of the dash lights especially the fuel display which is a picture of a fuel pumo at Chevron and to the right of the pump are the letters "CO gal"
The next symbol is the mileage which reads "0" and then the mileage which is 17068.5 MILES
I will get those pics up asap.
Is is possible, the previous owner took out the inertia switch?
I can't find it in the trunk, either side and I looked behind the passenger kick plate as well: nothing.
JIM

 

[Action]

Did you look at the owners manual?

Action

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[JIMLOG22]

I have the owner's manual at hand always.
They show a picture of the inertia switch which always shows a red button/plunger on the top of the inertia switch.
I know what one looks like and yet, I do not see it anywhere.
JIM

 

[Action]

Look in the trunk. Drivers side. Behind the brace or support towards the front of the car.

Action

 

[JIMLOG22]

Hello Action,
The mechanic has identified that the rough idle is caused by the left bank of the cylinders is wonky.
He said we need to remove the entire distributor assembly in order to adjust the crankshaft to properly adjust the ignition timing.
JIM

 

[Action]

Hmmmm wonky, a technical term I have heard of.

Removing the distributor isn't that difficult. Removing it to get it in the correct position would only be necessary if it was removed in the past.
What keeps the left bank and right bank in sync with the distributor is the timing chain.
Timing chains do wear. With enough wear, the distributor can not function correctly.

Action