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Idling/stalling problems on 1986 Ford F150 Answered

I'm driving my brother's 1986 Ford F150 4.9 V6.  It sat, unused, for about a year before I started usuing it, and he didn't perform any maintanence.  Got it running in February and the biggest issue was (and still is) the carburetor.  It's functional, but only barely (apparently there was some bolts missing on the breather that weighed it down and stripped some of the bolts on the carburetor).  I took it in to the shop, and they did what they could without actually changing out the carburetor (I don't have the money to buy a new one, still).   I was told by the mechanic to idle the engine for up to five minutes, depending on the weather, to warm the engine. It's been working okay, as best as can be, but no huge problems.
But then the heat riser on the exhaust manifold broke off on Thursday (I borught it back to them to look at, they said the whole manifold would have to be replaced and it'd take 4-5 hours).  Again, broke, so can't afford the $500+ they quoted, though they said it'd noisy but okay to drive until then.  Then, starting about two days ago, the idling got kind of clunky and it will sometimes stall out if I'm stopped or idling for more than a minute or so.  When I'm driving, it's okay, but slowing or stopping it can idle (I know keep one foot on the brakes and the other periodically tapping the gas).

I really don't want to go back to those mechanics again (I get the impression that they're taking advantage of me being a girl), and if there's something I can do myself, I'd like to.  If there's suggestions or input of any sort, I'd greatly appreciate it.


I saw this:

santapaws1 answered
3 years ago

i posted a problem i was having with a 85 f150 with a 4.9 after
putting on a non feedback carb. you might want to check it out to see if
you are having the same problem. since they put feedback carbs on 85
and 86 and only these 2 years are the same if you put on a feedback carb
other than 85 or 86 it will screw up the computer because the solenoid
is diffrent. thats why i'm changing to a duraspark ll system. to
eliminate the problem's i was having. check out [85 carb swap]

I thought my 1986 Ford 150 has a carburteter problem, stay tuned, hopefully I will get some answers soon.

Google this, My 1986 Ford 150 got a new manifold, and it has a known problem, I was told by my cousin that CAN be fixed....however, I have no way to give you details, I was googling it and found your note here. Maybe a student or a junior college with auto mechanics service would be interested in solving the problem? There is a solution, but my cousin does not have time to fix it.

my 1986 ford f150 will for some reason be running fine then all of a sudden it will shut down. I have to leave it sitting for 30 mins to a couple of hors then it will start and run fine for a while. Any idea what the prob might be?

i'm in the exact same situation except i'm a guy (smile) & i KNOW i can't afford a mechanic-even ours, whose a friend of the family & CHEAP. mine sat for TWO years. i got it running, had a gasket leak, got it running again-now it won't start-it tries but something is off. you can rebuild your own carb-just get all the info including the numbers off the little metal tag ON the carb, OR you can buy a rebuilt carb off e-bay and install it yourself. neither is hard-the first thing i do with any vehicle i work on is buy a manual (25$ & worth 100$!) it troubleshoots & goes thru ALL repairs step by step) THE ONLY WAY YOU'RE NOT GOING TO GET RIPPED OFF BY A MECHANIC IS TO LEARN, & DO EVERYTHING POSSIBLE AT HOME!!!.....all my love

yo man

8 years ago

well you could remove the bolts and find new ones.

In your note I believe you stated that some of the bolts holding the carb on may stripped.  The carb must make a good seal with the intake manifold.  If air is allowed in between the carb and intake the air/fuel ratio will be thrown off.  Start by making sure that the only air only goes in the top of the carb and not in from a bad seal at the base.  The heat riser will not imediately heat the air coming into the engine.  Does the engine run rough imediately after starting?  Good luck.

You could look for the parts you need on-line. It sounds like you already know your way around the nomenclature, and if you get wrenches with long enough handles you should have too much problem swapping out a manifold. I think the root of all your problems sounds like your carb.


You might also check for a U-Pull-It auto scrap yard near you. I've found some very good deals on parts that way. You might be able to repair the manifold with JB Weld, at least until you can scrape up the cash for a replacement part.

You're probably right about that, but I've heard of it being done with alleged success. That may have been further down the manifold, though. I hereby retract JB Weld part, just in case.

Welding cast iron is an art in itself - you have to preheat the casting, weld it with nickel rods, and then allow it to cool very , very slowly.

I envy people who can weld. One of these days I'm going to learn. I own a stick welder that I inherited from my grandfather, but I'm afraid that without proper training, I'd just electrocute myself.

You'd struggle to fry with a welder, there's usually no more than 30V on the tip, open circuit. Took me years to get welding right, because I don't do it all the time.


You have clearly underestimated my mad skillz in the area of electrocuting myself. Fire and I get along famously, but electricity... not so much.

We have U-pull-it here now ! Thanks for the tip. There's only one in England, though its only 50 miles from here (that's a long way to one from the old country....)


How's that saying go? Something like "In the UK, they think 100 miles is a long way, and in the US, they think 100 years is a long time"?

If you live near a pick and pull junkyard, they're a treasure trove of really cheap parts.  You just have to find out what years and models will fit your particular vehicle, and go see what's available.  While you're kind of guessing on which parts will be good, if you're really suffering for money, the savings will make it worth the extra hassle.  I've always driven older cars and often pull parts I don't even need such as altenators that wear out just to have handy as spares.

.  It sounds a lot like the choke to me, but difficult to tell without actually watching the carb working. You can buy an electric choke conversion kit. Instead of using heat from the manifold it has a small electric heater inside the choke housing. I have one on my old Mustang's Holley carb and the heat riser port in the exhaust manifold is plugged off.