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Pavlin Koev
Pavlin Koev, CERTIFIED TECHNICIAN
Category: Ford
Satisfied Customers: 3483
Experience:  17 YEARS HANDS ON EXPERIENCE, TRUCK&COACH TECHNICIAN LICENCE
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1987 ford F150: wont start..cap and rotor button, coil and it

Customer Question

1987 ford F150 won't start changed the dist. cap and rotor button, coil and it has good fuel pressure. Replaced the fuel pump relay and the pump will not stop running even with the key off.
Submitted: 6 years ago.
Category: Ford
Expert:  Pavlin Koev replied 6 years ago.
Chat Conversation Started
Pavlin Koev :

Hi, this may be 2 differnt issues

Pavlin Koev :

is your distributor turning when engine is cranked?

Customer:

yes

Pavlin Koev :

And I guess you have spark at plugs

Customer:

no spark

Pavlin Koev :

do you have power to coil?

Customer:

yes

Pavlin Koev :

missing ground then, need few minutes to check, have not work on those for a while.

Customer:

the ground is good

Pavlin Koev :

ground has to pulsate in order to make coil produce voltage.

Pavlin Koev :

so I will say Hall sensor in distributor is gon bad.

Customer:

what about the control module

Pavlin Koev :

it is possible, sensor is cheaper and fail more often

Customer:

the local auto parts do not list that sensor

Pavlin Koev :

one minute please

Pavlin Koev :

click HERE

Customer:

that is the control module

Pavlin Koev :

i will call it ignitor

Pavlin Koev :

if they do not sell pick up coil ot hall sensor, then look for used distribuotr.

Customer:

I have replaced everything inside the distributor bought a new control module and the motor just turns over? Its not even trying to fire.

Pavlin Koev :

what about engine compression?

Customer:

the compresson is good

Customer:

I am going to re time it in the morning

Pavlin Koev :

sorry my computer wend down.

Pavlin Koev :

check fuel injectors

Pavlin Koev :

you have to have power on one of the wires and pulsating ground on the other one,

Customer:

ok could it be spark plugs?

Pavlin Koev :

if you do not have that injectors do not function

Pavlin Koev :

disconnect each injector and try to start, if you have shorting injector it will shut system out.

Customer:

ok i will try that in the morning

Pavlin Koev :

ok, good night!

Customer:

could it be the computer? I am not getting fire out of the coil

Pavlin Koev :

No, I do not think it is computer. again with distributor cap off, look if distributor rotor is turning.

Pavlin Koev :

distributor hall sensor is sending the crank signal to computer and ignitor module bolted on the side of distributor. that is what will make coil to fire.

Customer:

I can hear the fuel pump running even with the key off but no pressure @ the rail?

Customer:

fixed the fuel problem it was a wire on the relay

Customer:

I am starting to think that the timming chain is bad if I turn the distributor while cranking the motor it does not slow down or speed up the cranking speed and it wont fire or back fire so I am thinking that the chain broke?

Customer:

Forget that just found out that this motor has gears

Customer:

I have replaced the hall sensor and the same problem no fire from the coil?

Pavlin Koev :

aRE YOU THERE

Customer:

yes I am

Pavlin Koev :

I HAVE ASKED YOU IF DISTRIBUTOR IS TURNING, THIS ENGINES HAVE PROBLEM WITH CAMSHAFT GEAR. BECAUSE IT IS PLASTIC AND GRINDS THEETH OF CAM GEAR.

Pavlin Koev :

I MEAN TURNING WHEN YOU CRANK ENGINE

Customer:

yes it is turning

Pavlin Koev :

HAVE YOU REMOVED DISTRIBUTOR AT ANY POINT?

Customer:

yes to replace the parts in side of it

Pavlin Koev :

WAS IT PLACED BACK IN THE RIGHR PLACE

Customer:

I think so

Customer:

the engine just turns over very fast

Pavlin Koev :

MAY BE THIS IS THE PROBLEM

Pavlin Koev :

IF ENGINE TURNS FAST,THEN YOU HAVE NO COMPRESSION, HOW DID YOU READED THE COMPRESSION/

Customer:

I haven't checked the compresson yet

Pavlin Koev :

GO BACK TO OUR CONVERSATION, AND YOU WILL SEE YOU SAID THAT COMPRESSION IS GOOD. CAN YOU CHECK AGAIN IF THAT DISTRIBUTOR IS SPINING WHEN ENGINE IS CRANCKED.

Pavlin Koev :

i THINK THAT CAM GEAR IS SHAVED, i HAVE DONE LOTS OF THOSE CAM GEARS.

Customer:

ok I will ckeck it

Pavlin Koev :

and please just tell me things that are confermed, otherwise we are not going anyware!

Pavlin Koev :

I cannot help you like that, and I realy do want to have this truck running, I have been thinking all day about it.

Customer:

The rotor turns while cranking, the compression is 140, and the fuel pressure is 58.

Pavlin Koev :

Ok, now you have to make sure distributor is placed in the right timing position. With engine at TDC on copmpression stroke ignition rotor has to point at wire point in distributor cap for cylinder #1

Pavlin Koev :

distributor is the part that makes the coil to fire.

Pavlin Koev :

will check with you later, have to leave now, have a good day!

Pavlin Koev :

Check voltages according to diagram. If all OK replace distributor.

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Customer:

I am at the point where the motor will fire if I spray it with eather but it will not run and the fuel pressure is still 58?

Pavlin Koev :

So you have spark at this moment, ignition coil is working

Customer:

yes

Customer:

no not yet

Customer:

I have not received anything yet

Pavlin Koev :

How you have got the spark? it is the same signal that is the same for computer to operate injectors.

Customer:

A wire was shorting out

Pavlin Koev :

check this spot or harness more detailed, it is same signal

Customer:

?

Customer:

I don't see anything about the crank single?

Pavlin Koev :

just a minute

Pavlin Koev :

Full Size Image

Pavlin Koev :

VREF wire is red color Signal return green

Pavlin Koev :

next thing to is check spout signal, yellow wire with green stripe going to computer pin 36. or you can check at distributor control if this wire gets 3V to 6V

Pavlin Koev :

also check voltage between pin 16 and 56 (look at previous diagram I have sended you)record voltage at time of engine cranking.

Pavlin Koev :

we are geting close.

Customer:

I am having trouble using a voltage meter but my brother is comming over to help me tonight

Pavlin Koev :

OK,

Customer:

ok this is where I am I ran a hot wire to the fuel injectors and it started I still need to check the timing and the firing order because it is missing and it is overheating for some reason.

Pavlin Koev :

Hi, at starter relay, or solenoid at engine compartment. there are few wires connected to it, those wires have fusible links incorporated in them. the one that supplies main EEC relay which inturn supplies the injectors is brown color. Fusible link N

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