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trouble shooting stock 383 issue

Posted By: GOLDMYN

trouble shooting stock 383 issue - 09/20/16 09:24 PM

Hi, I recently purchased(june) a 1965 Chrysler 300 w/stock 383/325. The car had 51K original miles. I drove it perhaps 200 miles over the course
of 2 weeks and the car ran great w/o any issues. The first time I experienced the problem,I was just taking off from a parking area and the car just started to stumble and lose power(no popping or backfire) but didn't die. I continued on my way. I changed the stock fuel pump/filter and plug wires and continued to drive the car. I drove this car all summer in every condition possible w w/o issue. The car starts and accelerated perfect.
I put on another 700 miles. This past weekend we started on a drive and perhaps 10 miles into the trip, again going down the road @40mph it again stumbled w/loss of power but regained power. We continued on, drove another 130 miles w/o issue, both stopping/starting and normal driving. Today, I sprayed lube on the carb linkage for lack of anything else to do. I've checked all connecting and can't find anything lose. Today I drove the car and got to my destination, started back up after 2 hours, started fine, turned the corner, went 2 blocks and again the stumble, this time the engine died. I pulled over, pumped the gas once, car started up great with no backfiring or roughness. I drove home about 20 miles and again experienced no problems. anyone care to point me in a general direction? Gas or ignition? The carb is the original (AFB) never rebuilt and the ignition is bone stock points....thanks
Posted By: p d'ro

Re: trouble shooting stock 383 issue - 09/20/16 09:33 PM

I guess not heat soak or vapor lock. Maybe a gunked fuel tank and your new filter is getting clogged again?
Points or elec. ignition?
My Bronco had a similar issue and it turned out to be dirty electrical connectors going to ignition wire (it has a bullet type). I think your smay be the bulkhead. I am always nervous pulling these apart, but it may hav corrosion. A cleaning and then some dielectric lube may help.

Sorry, with my limited experience that is all I have to offer. If it feels the same as before and wires/fuel filter fixed it, that is a good start.

Good luck.
Posted By: poorboy

Re: trouble shooting stock 383 issue - 09/20/16 10:46 PM

I suspect you have a gas issue. The swill they are calling gas these days really does a number on the rubber of yesteryear. There are rubber hoses in your gas line, and rubber parts in the carb that the new gas will not play well with. Your probably experiencing those rubber parts & hoses starting to disintegrate. I suggest you stop driving it until at least you get the rubber replaced in the gas lines and put a new carb kit in the carb.

There may still be an issue with the points and condenser, but the fuel lines can cause a fire, replace them first. Gene
Posted By: an8sec70cuda

Re: trouble shooting stock 383 issue - 09/20/16 10:50 PM

If it still has the factory sock filter on the sending unit in the tank, take it out and remove the sock filter. One filter up by the carb is plenty.

For testing purposes, get one of those clear glass filters so you can see what it's doing. If it's filling w/ rust, you know you need to replace lines and/or the tank. When it starts acting up, you can also see if the filter is full of fuel or if it is pumping bubbles.

Definitely replace all rubber fuel line like the others suggested.
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 09/20/16 11:25 PM

thanks for the comments
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 09/20/16 11:49 PM

Perhaps I'm missing something, but shouldn't taking off the fuel filter and blowing air through it tell me if there's any contamination in the tank?
Posted By: RapidRobert

Re: trouble shooting stock 383 issue - 09/21/16 12:42 AM

I would take the neoprene line off of the tank sender & blow shop air into the sender hard line nipple to blow the sock off of there then if still an issue, open up the carb top & blast it out good with brake kleen
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 09/21/16 01:26 AM

so far,everyone thinks fuel is the culprit? I would mention that there is no sputtering, popping or running rough just before the loss of power.
Posted By: Powerflow

Re: trouble shooting stock 383 issue - 09/21/16 02:01 AM

This is a long shot, but have you checked the little wire in the distributor that goes to the points? If the insulation is bad it can ground out and cause the issues you're having.
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 09/21/16 02:06 AM

Originally Posted By Powerflow
This is a long shot, but have you checked the little wire in the distributor that goes to the points? If the insulation is bad it can ground out and cause the issues you're having.


Thanks, I'll check that tomorrow
Posted By: Sxrxrnr

Re: trouble shooting stock 383 issue - 09/21/16 03:31 AM

Bad ballast or wiring to it from ignition switch. Next time it happens run jumper from battery + to coil +. Problem cease? Investigate all of above. I also like dirty tank idea. Possible dirty carb or sticking float needle.
Posted By: poorboy

Re: trouble shooting stock 383 issue - 09/21/16 03:32 AM

I started with the fuel because I've seen what the modern gas does with old rubber parts and hoses. Other then replacing the filter, you have made no reference to doing anything else to the original fuel system. Fixing anything else and ignoring the gas and the old rubber issue is a disaster waiting to happen.

A 51 year old car with 51k miles on it has spent a lifetime sitting. Fuel systems deteriorate over time. Everything in the fuel system (in addition to the rubber) could be junk, including the tank, the fuel pickup in the tank, the steel lines, the fuel pump and the carb. A pinhole in a hose or steel line will give you what you are experiencing, and may not leak any gas at all, you only need a little air separating the gas to cause a stumble, and it can come from anywhere in the fuel system.

Old point style ignition systems are generally not effected by time, they usually work, or they fail completely, or there is an issue with wires or wire insulation breaking down. Who knows what rodents may have done to the wiring on that car in 51 years, they do like to chew on wires.

You have a 51 year old car with 51,000 miles on it, most were probably put on 20 years ago. Don't expect to jump in and drive it like you would a modern car with 51,000 miles on it. Unless everything has been kept up to date, things like brakes and wheel bearings, tires wipers, and a bunch of other stuff needs to be serviced simply because that stuff may be very old, or the next thing we will hear is "My brakes failed, what happened?" Gene
Posted By: Supercuda

Re: trouble shooting stock 383 issue - 09/21/16 03:43 AM

Poorboy makes a good point.

When I buy vehicles like the OP's I replace the rubber fuel lines as a matter of course with new fuel injection rated hose. Costs more but I think it's worth it. NOt to mention brakes, ignition, etc.

For all we know there are chunks of crud in the tank from all those years sitting and it's getting sucked up to the pick up, cutting off the gas flow then floating away when it stalls out and dies.
Posted By: Crazy68Dart

Re: trouble shooting stock 383 issue - 09/21/16 03:50 AM

Considering you drove it for 700+ miles and all of a sudden it started acting up again... I would be suspicious of the fuel pump. I've seen pumps fail early (bad rebuild, etc.).

If it were one of the other issues mentioned, I would have imagined you would have been fighting issues all along. That said, don't ignore the fact that all the rubber, etc. might be shot and/or near failing.
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 09/21/16 04:26 AM

Thanks everyone for your comments, This car just hasn't sat for the past 20 years . Many of the items mentioned in the texts above have been address.The entire cooling system with belts/hoses, the entire braking system, plugs/wires, exhaust, tires/bearings,fuel pump, filter, heck even the aftermarket ac which was installed in 1969 has been updated with all new parts and Freon and works great. Go out in the morning, push the gas peddle down, release, turn the key and boom, starts nice, no stumbling, high idle, slap the peddle and high idle come down, engine purrs. Take the car out on the highway and cruise at 65 w/o surging, stumbling, hesitation, kick in the passing gear and instant acceleration. just to give readers a flavor for the type of car. yes, the rubber is old and carb hasn't been rebuilt and sure I can have those done. just seemed to me that I would have experienced some issue in the past 700 miles and now in the past two days the symptoms have appeared twice.
Posted By: RapidRobert

Re: trouble shooting stock 383 issue - 09/21/16 05:00 AM

Quote:
just seemed to me that I would have experienced some issue in the past 700 miles and now in the past two days the symptoms have appeared twice.
you might plumb a can of gas to the pump inlet & see it it recreates. that'd elim everything rearward from the pump
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 10/27/16 02:51 PM

UPDATE. After changing the complete fuel system from to the gas tank pulled, cleaned and sealed, new rubber everywhere, new fuel pump and filter and rebuilt carb, the car did the same thing. Changed the points/condenser and problem solved.
Posted By: JohnRR

Re: trouble shooting stock 383 issue - 10/27/16 04:06 PM

Originally Posted By GOLDMYN
UPDATE. After changing the complete fuel system from to the gas tank pulled, cleaned and sealed, new rubber everywhere, new fuel pump and filter and rebuilt carb, the car did the same thing. Changed the points/condenser and problem solved.


It didn't sound like a fuel issue to me. Hopefully you left the sock on the pickup tube.

Good find.
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 10/27/16 06:10 PM

Oh yeah, after having the tank cleaned and coated, I was able to use the old sending unit but did put a new sock on it. I had my reservations that it was a fuel issue but nearly all of the responses on here suggested fuel so I took that avenue. Now in the future if I have any issues, I can cross fuel related off the possible culprit.
Posted By: RapidRobert

Re: trouble shooting stock 383 issue - 10/27/16 07:59 PM

Hopefully the tank was in need of attention to some extent so that we didn't totally contribute to you wasting your money (& time).
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 10/28/16 06:40 PM

Tank was in serviceable condition, but since I had it out I believe in prevention rather than trouble years from now when it'll be impossible to find someone who seals tanks, The way it was, there was no one in the town I live in, people look at you like your from Mars.
Posted By: minivan

Re: trouble shooting stock 383 issue - 10/28/16 07:46 PM

Originally Posted By GOLDMYN
UPDATE. Changed the points/condenser and problem solved.


I knew a good mechanic in 71 who could not get a car to run right no matter what he did... Common thing back then was to change the points but leave the condenser... After trying everything he knew in installed a new condenser, problem solved..

Your post ending made me think of this.....
Posted By: Sinitro

Re: trouble shooting stock 383 issue - 10/29/16 02:58 AM

Check the bulkhead wiring connectors (3)...
After 50 years they get corroded and oxidized..
Pop them apart, burnish the contacts, recrimp the female tab conectors on the firewall side, coat with dia-electric grease and reinstall...

Just my $0.02... wink
Posted By: GOLDMYN

Re: trouble shooting stock 383 issue - 10/29/16 01:07 PM

Originally Posted By Sinitro
Check the bulkhead wiring connectors (3)...
After 50 years they get corroded and oxidized..
Pop them apart, burnish the contacts, recrimp the female tab conectors on the firewall side, coat with dia-electric grease and reinstall...

Just my $0.02... wink


? problem solved
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