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84 Mercury Cougar not firing but sparks


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sargerock
User

Sep 11, 2009, 4:59 AM

Post #1 of 24 (3528 views)
84 Mercury Cougar not firing but sparks Sign In

1984 Mercury Cougar 5.0 8 cyl 170,000 miles carb.

was running fine till other day when just wouldnt start. turns over ok, good spark from coil and to plugs, new plug wires. gas flows to carberator when key is on,when i remove fitting before carb ..... but when accel is pumped, i see no gas coming from out of jets coming from duel carb. I can pour gas or starting fluid and still NO fire or any sort of kick over!!!!!!

thanks

Greg

ps also replaced ign coil and pressure regulator


(This post was edited by sargerock on Sep 11, 2009, 5:02 AM)


Tom Greenleaf
Ultimate Carjunky / Moderator
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Sep 11, 2009, 6:23 AM

Post #2 of 24 (3519 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

Check compression to see it timing chain jumped,

T



sargerock
User

Sep 11, 2009, 6:37 AM

Post #3 of 24 (3515 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

its a belt not chain :)


Hammer Time
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Sep 11, 2009, 7:08 AM

Post #4 of 24 (3511 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

OK, let me clear you up on a few things

First, if you have a 5.0, then you don't even have a carb, it's fuel injected and it has a timing chain, not a belt. It sounds like you may need someone else to diagnose this for you. I'll give you the procedure.


All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.



Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.


2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.


3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

Once you have determined which of these functions has dropped out,
you will know which system is having the problem.



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
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Sep 11, 2009, 7:12 AM

Post #5 of 24 (3508 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

It's a chain and the OE had a nylon cam gear that would break up with age even with well cared for cars.

The 5.0 (302 cid) never used a belt TMK - part looks likes this and is a PITA to get water pump off to get to it if this is the current issue at all. If not it will be if an original chain set!


T



Tom Greenleaf
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Sep 11, 2009, 7:22 AM

Post #6 of 24 (3504 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

Hammer - are we cossing swords thru the air waves again? Took me longer to find the pic then YOU to write a reply!

Tis not unusual for the OE nylon gear to be erratic like this but would near certainly show uniform low compression and could snap out of that during a test causing all kinds of hair loss to diagnose. I know these gears if OE they don't usually do that much time!

T



Hammer Time
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Sep 11, 2009, 7:42 AM

Post #7 of 24 (3498 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

I totally agree but at this point all we know about the problem is that we have spark. That leaves a lot of possibilities still.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



sargerock
User

Sep 11, 2009, 7:56 AM

Post #8 of 24 (3494 views)
post icon Re: 84 Mercury Cougar not firing but sparks Sign In

dude, its a carb.....2 barrel...and theres no doubt, a motocraft


Hammer Time
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Sep 11, 2009, 8:00 AM

Post #9 of 24 (3490 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

What's the 8th digit of the VIN#?



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



sargerock
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Sep 11, 2009, 8:03 AM

Post #10 of 24 (3487 views)
post icon Re: 84 Mercury Cougar not firing but sparks Sign In

fuel is spewing up to carb when i turn on ignition, , pump accel cable, no fuel from jets.and i have ign key on...........i installed new coil, sparks are all good at all plugs, , and i replace all 3 belts including seep when car turns over, spark plug testor flashes good, but no fire with starter fluid. and again, it was a serp belt i rpl.


sargerock
User

Sep 11, 2009, 8:06 AM

Post #11 of 24 (3485 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

the letter f


sargerock
User

Sep 11, 2009, 8:09 AM

Post #12 of 24 (3482 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

1mebp92f.....


Hammer Time
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Sep 11, 2009, 8:12 AM

Post #13 of 24 (3481 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

If the VIN code is "F". then the car came with a fuel injected engine. You talk about fuel with the key on indicating an electric fuel pump. That is only used with fuel injection. If someone slapped a carb on that engine, it's not going to work.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Tom Greenleaf
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Sep 11, 2009, 8:13 AM

Post #14 of 24 (3478 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

Hammer spelled this out about as well as you'd see anywhere on the web! Spark, fuel, compression and you would have some reaction. I maintain that if the timing (valve) is so far off it won't react - got the T-shirt! Carb, injected or not almost doesn't makes a rat's a$$ right now!

T



Hammer Time
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Sep 11, 2009, 8:21 AM

Post #15 of 24 (3471 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

It will make a hell of a difference is someone was foolish enough to stick a carb in front of that electric fuel pump. He says it's pouring fuel out everywhere.



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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



sargerock
User

Sep 11, 2009, 8:21 AM

Post #16 of 24 (3468 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

ok i dont say i dont believe you, but yes it has a fuel pump in back next to fuel filter...it has 2 wires going to it.....and when u turn on ign it spews out...and it has a 2 barr carb..and the cars run since 1984 ....without any modifications...

sorry but i think i know what a carb looks like....like i said..ran fine till i parked at church for 20 min....then it started for like 10 sec....never fired since


sargerock
User

Sep 11, 2009, 8:23 AM

Post #17 of 24 (3467 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

and big words say motocraft on carb


sargerock
User

Sep 11, 2009, 8:24 AM

Post #18 of 24 (3466 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

what controls injector pulse ?


sargerock
User

Sep 11, 2009, 8:26 AM

Post #19 of 24 (3465 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

and putting starting fluid WITH a spark at all plugs still gives nothin


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 11, 2009, 9:20 AM

Post #20 of 24 (3451 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

Is this what it looks like?






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We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Guest
Anonymous Poster

Sep 12, 2009, 9:29 AM

Post #21 of 24 (3445 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

yes


sargerock
User

Sep 12, 2009, 9:32 AM

Post #22 of 24 (3440 views)
post icon Re: 84 Mercury Cougar not firing but sparks Sign In

yes thats it :)


Hammer Time
Ultimate Carjunky / Moderator
Hammer Time profile image

Sep 12, 2009, 9:40 AM

Post #23 of 24 (3439 views)
Re: 84 Mercury Cougar not firing but sparks Sign In


Quote
dude, its a carb.....2 barrel...and theres no doubt, a motocraft



Quote
sorry but i think i know what a carb looks like.


Well, apparently not because that was a picture of the Throttle Body fuel injection that the car came with.

Here is that same picture without the words "fuel injection" whited out. Maybe you'll listen next time.






~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.



Guest
Anonymous Poster

Sep 12, 2009, 10:17 AM

Post #24 of 24 (3432 views)
Re: 84 Mercury Cougar not firing but sparks Sign In

yes i am so wrong, i didnt even think of this being so old a car....woith the butterfly chokes n stuff it just reminded me of a carb...so if then,,,, what next? compression?






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