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I have a 1966 289 that is 30 over, it has a full MSD ignition (distro, wires, 6AL-2). It has a new Edelbrock 600cfm carb (less than 5K miles) with a clear fuel filter near the carb to see fuel flow. Recently the car stopped running. Thinking it may be a clogged carb or fuel filterI went through the carb and cleaned out any old varnished fuel and replaced the filter with a clear one. Still no fire so I checked the ignition.

I was able to find the old Digital 6+ ignition had given up the ghost and I replaced it with the 6AL-2. While I was at it i replaced the plugs, wires, cap and rotor on the MSD Pro billet distributor, and the Blaster 2 coil is brand new as well. After doing all the maintenance the engine fired right up, but died after 30 seconds. I know it is getting fuel as I can watch it flow through the filter. Now the motor will not fire again and raw fuel washes down into the exhaust.

I know the spark is good and the fuel is the right mix (plugs were always the chocolate brown color all the way around). The only issue I can see is the radiator has sprung a leak but the motor did not even get warm enough to open the thermostat. I am at my wits end! can anyone help diagnose? thanks in advance!
 

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are you positive you're getting spark to the plugs and your distributor isnt 180* out of time?
is there any sort of popping or backfire while cranking?
 

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no popping or backfiring. the distributor has been in for a few years. I did double check the spark from the #1 cyl wire against a ground. also did the MSD spark check procedures (was how I found the previous box died). I made sure all wires kept the same firing order and when it did run for the 30 seconds it sounded great. That is why I am so confused:?:
 

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I have a 1966 289 that is 30 over, it has a full MSD ignition (distro, wires, 6AL-2). It has a new Edelbrock 600cfm carb (less than 5K miles) with a clear fuel filter near the carb to see fuel flow. Recently the car stopped running. Thinking it may be a clogged carb or fuel filterI went through the carb and cleaned out any old varnished fuel and replaced the filter with a clear one. Still no fire so I checked the ignition.

I was able to find the old Digital 6+ ignition had given up the ghost and I replaced it with the 6AL-2. While I was at it i replaced the plugs, wires, cap and rotor on the MSD Pro billet distributor, and the Blaster 2 coil is brand new as well. After doing all the maintenance the engine fired right up, but died after 30 seconds. I know it is getting fuel as I can watch it flow through the filter. Now the motor will not fire again and raw fuel washes down into the exhaust.

I know the spark is good and the fuel is the right mix (plugs were always the chocolate brown color all the way around). The only issue I can see is the radiator has sprung a leak but the motor did not even get warm enough to open the thermostat. I am at my wits end! can anyone help diagnose? thanks in advance!
Without hands on, lets start with the basics. You say you know you have good spark...
HOW DO YOU KNOW?!?
The only way to know is to test it with a gap tester (Or a screwdriver inserted in a plugwire and held 1/2 an inch to ground is slightly less accurate but usually works in most cases, finally grabbing a plugwire and holding it with your thumb over the plug end is most accurate...
if you get knocked to the ground and scream loud profanity, you have enough spark and thats not your issue. If you only get lightly zapped but not enough to curse, you have weak spark. If you wake up with a crowd around you and someone shining a light in your eyes...you have GOOD spark. Helpers are good for this portion of the testing. Especially those who have never helped you check spark before.

OK, if you get a scream, yours or someone elses...we will assume you have spark. If you DONT have a scream...or a good 25KV measured with a test plug (ST125 is most common) then start there.

You say you have gasoline in the exhaust.
Thats BAD. I dont care if you have NO spark, you should never have liquid gas flowing into or out of the engine. a light mist is all any engine runs on...if it comes OUT as liquid, its massively overfueled! Since you have a carburetor, most common cause of that much liquid in the engine is stuck or defective carb float. check the float status. On a holley its easy, they have a check screw for it, on an edelbrock you gotta pop the top...but it sounds like you possibly mis-seated something when you cleaned out the varnish?
Carbs dont need to be cleaned in the USA. We have detergent in our gas...if a carb gets dirty...its from deposits because you buy cheap gas and its not just in the bowls its in all the passages and jets and will require soaking to clean out of ALL the places its lodged. Unless a carb is already screwed up, I generally say theres no reason to open one (any brand). The modern gasolines make them mostly self maintanencing UNTIL something (like a float or a power valve or an internal gasket) actually breaks and makes them run really badly and then its better to do a full tardown/rebuild of the entire carb.

So lets start with the flooding thing. It can only be the carb UNLESS you did something with the fuel pump. Ive seen a few guys install aftermarket electric fuel pumps because they think anything racy and new is better than original...and then the car doesnt run because the original mechanical pump put out 4psi and they replaced it with a chrome plated electric that was as loud as a rock drummer and put out 60PSI unregulated! That would do what you are experiencing. Hopefully that isnt what happened. Stick with the stock mechanical pump, its fine even for racing engines with carburetors until you get over the 450hp level.

OK, so we have the tests. CHeck for 25kv spark...which is enough to jump over 1/2 an inch to ground from a plugwire connected to a screwdriver and held near whatever ground is available. Thats 1st.

Too much gas is BAD. Not only does it wash out the plugs and make them unable to fire, it washes the rings and kills compression, causes gap bridging, etc etc. If you see gas dribbling in the carb while its being cranked its too much. You say you see gas in the filter, I suspect your carb is flooding the engine since you say it drips from the exhaust. Pinch teh rubber fuel hose going to the carb with a visegrips. keep cranking, in a few seconds the lack of new gasoline reaching the carb will allow it to work as designed temporarily. However if the cylinder walls washed out it may take longer. If the compression is gone because of excess fuel...get the gas prob fixed, and drip or squirt 10-20 drops of motor oil down each spark plug hole, then reinstall the plugs. The oikl will lube up the rings and help restore the compression.

Aside from that, you should be on the road. verify spark 1st, if it wont start, crank for 10 seconds then pull any spark plug. If you had spark before cranking for 10...abnd the plug is wet with liquid gas, your carb is screwing up and flooding the engine. if plug is lightly moist but not dripping, and you know you have spark...then check conmpression. anything over 110 should start OK, 95 or 100 might even start. normal for you would be 130-160 usually but as long as its over 100 it will fire on it.

hope it helps./
 

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Hello 1966_coupe,
FIRST - -you hav ebeen given some real solid ideas and info.

I would like to add a few thoughts as well.
1. - I doubt you have gas dripping out the exhaust. Not logical
and would take a LOT of gas to reach that point. MOre likely what you
see is condensation.

2. - -Sounds like something is not right in the carb and most likely will
need rebuild. I am curious - -when you cleaned the carb - -did you soak it
in carb cleaner or just wipe the bowl?
Keep in mind there are tiny passages in the carb that can and will gum
up with varnish from stale gas.

I advise the use of "Stabile" if the car will sit for more than 2-3 weeks at a time.

One thing that may help you confirm the carb is the issue is to try some
starter fluid. CAUTION - -starter fluid is volatile and should be used sparingly.

I would spray about about 3 seconds of starter fluid into the throat of the carb - -then put on air cleaner (can leave loose) and see if she attempts to fire up.

The starter fluid will wash the cylinder walls as well and caused a pretty strong
ignition in the cylinders - -so use it only once or twice. This MAY get you started
but I am thinking you have CARB issues.

Double check the spark at #1 or any plug and keep in mind even "new" coils are found to be bad.

It must be dumping a lot of fuel into the motor. Of course - -this could indicate the floats are not working or as mentioned - -if electric pump - -blowing by the needle and seat.

Let us know and we can go from there

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Discussion Starter #6 (Edited)
Update

All of those were great ideas! Thanks to all.

after much tinkering with the fuel I was able to recreate the 30 second run time again tonight. this time I started the engine from the solenoid and hand manipulated the throttle. I noticed the eletric choke never disengaged and the motor sounds like it is starving for air. The mix is good from the jets and carb is now spit-spot clean with fresh 91 running through it. I tried to touch the electric choke body and it is scorching hot! i am in no way going to drop any more $ into this fricken brand new carb and since I live in the desert I have no need for a choke. any advice on cheaply disabling the device?

getting close to having my baby back!

Edit: Choke butterfly will not move when warmed up. 12v switched voltage applied correctly. to get motor to start initiall i had to "dial" it open by hand. choke got so hot thought it may catch fire!
 

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To disable the carb, either remove the power wire, or loosen the 3 screws on the housing, and rotate the housing clockwise until the plate opens a tiny bit, then start the car and see if the choke works, if not, leave it unplugged.
 

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In my Modifying and Tuning Holley Carbs book, they remove the choke plate from the carb. They say you don't need a choke, your car will start without it, just may have to warm it up a bit before you drive. Seeing as you live in AZ, you won't need it in the summer anyhow, and in the winter, you will just have to take time to warm it up before taking off. Most people warm it up
 
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