'73 302 Mustang.......ignition problem or not !!!

choppermutt

I've noticed that my mustang acts up sometimes when it is hot and you try to start it. Prime example today - Drove for 15 or 20 miles.......stopped for 20 minutes.........no way would it start when I went out to it. Was only a mile from home so I towed it.

Got home, had a look for maybe 30 mins then pulled a plug to see if I had spark while my wife turned it over........and of course it started

Now while I had noticed that it always takes a few extra turns to start it when hot it has never flat out refused me before. Is this a sign of a coil problem or is it just a "mustang thing"

Petronix ignitor ignition system with matching flame thrower coil

1948Wolseley

It could be the coil, or it could be fuel vapourisation too. If it happens again, check for a spark immediately, while it's still hot.

If you do have spark, I'd suspect you have a fuel vapourisation problem. Squirt a small bit of fuel down each of the carb barrels and then try starting it (Be careful when you're doing this with a hot engine: make sure the ignition is off, and try not to spill fuel on anything hot and/or electrical). If it then runs fine, or runs for a short while and cuts out, you've found your problem. As for how to fix it, you'll probably have to re-route some fuel lines, but I'd say your best bet is to talk to a Mustang guy!

choppermutt

;)Thanks for the reply 1948. Doesn't seem to be fuel issue. Manually squirted carb while it was hot - no joy. I'm thinking coil myself and those flame thrower coils seem like a cheap fix if it does the business

Kevin_Herron

My Galaxie 500 runs a 390ci big block and I have had the same hard starting problems when hot. Quite embarrasing on a rally!

I always put the problem down to fuel vapourisation, it would always fire up after winding over for a bit.

I would start at the coil.

mustang68

I'd start with the coil too, cheap fix and if it wasn't the problem a new coil is a good thing to have.

Not starting shouldn't be a Mustang Thing

Dades

Had the same issue with my 924. Less of a hot start issue - more of a warm start one. Fitted a push switch that grounds a cold-start-valve and squirts fuel in when cranking.

I think that issue is supposed to be caused by vapour in the lines.

bazzjazz

Probably totally unrelated but....

I had this issue with my 77 Daimler and it turned out to be a faulty choke. It was stuck on all the time, so as soon as the engine heated up, it would cut out and wouldn't start again, as it was flooding, until it had cooled down.

choppermutt

Thanks for the replies. I'm going to go with the coil for now - ordered one from MustangsUnlimited - only $34 for a flame thrower. Like you say even if it turns out to be something else..........it won't go to waste. Engine dress-up kit coming too:D

Big Nasty

Chopper, did you check on the AMCI site as somebody with a yank tank has more than likely come across this at some stage before.

choppermutt

Hey MCM........didn't have much luck there the last time. Must have posted in the wrong area or something. Wll try again if the coil doesn't sort me out

Big Nasty

choppermutt wrote: »

Hey MCM........didn't have much luck there the last time. Must have posted in the wrong area or something. Wll try again if the coil doesn't sort me out

Like any forum sometimes you can just post at the wrong time! If other stuff is going on or it's 10pm on a Saturday night your post might get missed. You're down Cork way IIRC, you should join this forum: www.gascc.ie (American Car Club in Cork) but feel free to post on our site any time too!

choppermutt

I tried the mustang again this evening.......coil is on back order so everything is as was - no new parts

Car started first turn of the key. Perfect no problem. Left it idle for about minute then gave it a little gas. Then I noticed it wasn't idling so well and eventually died, Started her up again but it just wouldn't idle witout me keeping the pedal pressed a little. eventually it stopped and no more starting after that

Unlike the last time I had tools. Removed 2 plugs and turned the engine over. Both sparking fine.
OK so it must be petrol. Opened connection to the carb (Holley) turned it over. Gas flew out. No problem with petrol supply. Manually pumped throttle and sure enough petrol came out freely

So have gas and have spark and the car hasn't undergone any mechanical work that would affect timing.

Any ideas.....

Will try AMCI later tonight

Big Nasty

Dude, I'm no mechanic - when stuff goes wrong I cry for help and one of the lads come along! That said I've been very lucky with the T/A, she gives me little or no bother.

Is she running too rich / lean, causing the spluttering? Howza bout the points? You can easily change them to lekky ones.

Just discovered that one of our lads used to own your car a good few years back!

kasper

dont know these yank tanks but on a conventional ignition system it sounds like the gap in the points is set too wide , the heel of the points that sits on the cams wears and needs perodical adjustment

choppermutt

Cheers lads but has electronic ignition. As for running rich I would say............possible. Wouldn't expect them to spark so well when removed though and it tends to either run or not - doesn't splutter. Pipes definitely have a sooty coat.

kasper

the only other thing i can think of is a crack or leak in the inlet manifold which is widening when hot

choppermutt

Interesting Kasper............I'll check that out over the next few days