ricmarcarp

Was driving my 69 Mustang with 351 Cleveland, when within a span of about 6 or 7 miles, it went from running fine, to a slight miss, to totally undrivable. Have had it to two different places (one was a ford dealer) and the problem is not yet solved. Would this be an internal problem. Not a real mechanic so I am at the of others. Help

mjr46

if it's a solid misfire, pull one plug at a time with an insulated set of pliers until you find one you pull that makes no audible change in the way the motor runs, as you pull and replace the wire back on the plug you should be able to tell if it's contributing by the way the motor will start to run rougher.....when you find one that makes no change, check to see if it has spark to that cylinder with an inline spark checker, if it does check the plug for any cracks in porcelin, if plug is okay, do a compression test on that cylinder and report back with findings.

barnett468

hello;

major bummer.

I’m curious, what did they say?

It’s just an engine. For two shops not to find the problem tells me that they have no idea what they are doing. Lots of these guys are just computer changers nowadays. Real mechanics are fewer and farther between all the time.


I would go to a local show or look up a vintage car club and ask them where they go.

Did it or does it make a mechanical clanking sound?

Can you explain what happened in more detail?

do you have a pertronix unit on it?

A compression test is a good thing to try in addition to checking the electrical.

try these guys for info on shops if you want

http://www.mocsem.com/default.php

http://westmichiganmustangclub.com/
.

ricmarcarp

They have tried changing plugs, plug wires, checked timing, even different dist., and carb. Idles fine until it begins to warm up, then spits and sputters. Also different coil. Compression also is good.

mjr46

where is the fuel line routed?? close to exhaust?? also might want to do a pressure/volume test on fuel pump and make sure the pump isn't drawing air anywhere do to a loose clamp or split line somewhere.

Mustangdemon67

does the carb stop getting fuel after it warms up? next time it starts happening pull the fuel line off to see if its dry.

barnett468

ok, sounds like electrical to me or possibly flooding.


when it is cold, how long does it run before it does this?

how long does it have to sit before it restarts and idles perfectly again?


i would do the following:

if you have an electric choke connected to an ignition wire i would remove it for now and set your choke to full open.

if it has to sit for around 20 minutes or more before running properly again than try standing your coil up in a pan of ice water before running engine and try it like that or after it dies put it in ice water for 10 minutes and try it again and if it restarts your coil is definitely bad.

if you have a holley carb, set the gas level in the carb so it is just below the inspection windows with the engine running.

watch the gas level, if it gets lower then either your pump is bad or you are probably sucking up debris like rust in the gas tank and it is clogging your filter.

remove the positive wire from the coil and run a wire from the battery to the coil. disconnect it when not testing engine.

try a different coil than the one they tried.

if none of this fixes it, i would try a new condenser. if you have "updated" your stock distributor with an electronic system, i would reinstall a points set up.
.

Chromeshadow

If its a fuel issue, you can spay starting fluid in the carb, if it runs its a fuel issue.
It's possible that heat is causing a vacuum leak, starting fluid will make the car run, but that doesn't always mean its a carb prob. A $15 vacuum gauge will tell you a lot about your engine, you can easily hook it up to a hot engine if you plan ahead.