Dreaded intermittent cutting out!

Gordon Peters · #1 (**permalink**) 02-14-2005, 06:20 PM

Ok here is the challenge, I have a 351 Ford racing crate engine which under normal circumstances flies. But after driving her for a couple of hours and letting her sit for about twenty minutes upon starting up and accelerating through first and when shifting into second and hiting it more times than not she cuts out and farts and wheezes barely staying running. I changed carbs from a Holly to an Eldelbrock but she still has the same intermittent problem. The plugs have been changed and the timing and vacuum advance are dead nuts. It’s a matter of not trusting her when pulling in to traffic. Any ideas?

Gord

wizard · #2 (**permalink**) 02-14-2005, 07:03 PM

My wifes SL500 had a similar problem. A year later and three trips to the dealer had no answers. Took it to the local foreign car guy and it turned out to be a coil(s) problem. When the coil got to the right temp with the right load, bingo. Since the coils replacement, run like a champ. Maybe not your problem, But at least another place to look. Good luck.

Gordon Peters · #3 (**permalink**) 02-14-2005, 07:27 PM

I’ll give it a try it will be a lot cheaper than all I’ve tried so far. I’ll let you know what happens.
Thanks Gord

bushwhacker · #4 (**permalink**) 02-14-2005, 08:19 PM

Might have your MSD circuts checked.

xlr8or · #5 (**permalink**) 02-15-2005, 12:20 AM

Pack a cooler with some ice packs and take it with you. After heat cycling the car it begins cutting out pull over and ice the coil down and see if it goes away. Same thing applies to the MSD box if it's in the engine bay. Also verify the wires going to the coil have a good solid and clean connection.

Gordon Peters · #6 (**permalink**) 02-17-2005, 04:22 PM

Well so far it’s not the coil or the MSD box as we swapped both of them and she still acts up. It does seem to be a gremlin in the electronics.
Gord

mzhun · #7 (**permalink**) 02-18-2005, 05:33 PM

sounds like some kind of vapor lock gremlin to me, does it start fine?

Gordon Peters · #8 (**permalink**) 02-18-2005, 08:05 PM

When cold she fires off instantly, when hot not quite as fast but not a show stopper. It’s after she sits for twenty or so minutes after a run that she can exhibit the missing problem. I replaced the rubber gas fuel line with a braided line thinking the fuel was heating up in the line when sitting but that didn’t help. The braded line looks better so it was not a total loss.
Gord

stockittome · #9 (**permalink**) 02-18-2005, 11:48 PM

Gordon
Get your trusty v/ohm meter and check for continuity the three wires going to the dist. pickup ( Ford duraspark ) at the same time stretching and pulling trying to cause an open. This would be from the MSD two wire connector foward.These are thin wires and by the weight of the wires and connector could cause an open from vibration and stress. This will not show up as a visual on the insulator, but as a break in the wire. Ask me how I know. Your meter should have very sharp probe points to penetrate the insulation. A new pickup costs about 20 bucks. Probably better to just get a new pickup. Do a google on r&r. Do not miss index the reluctor and be careful of that little roll pin. Make sure you have the proper air gap.

Good luck