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Stalling troubleshooting

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red1980F150

Stalling troubleshooting

Hey guys,

I could put this in the new members forum - I picked up at orangish-red (originally gray) 1980 F150 with a 302 and auto (original sticker denoting transmission code is gone, probably a c6?) in May 2020. I'm only the second owner! The founder of the company I worked my first professional job bought it new in 1980. It's very clean, but is starting to need cab corners.

Through the summer it ran really well, pretty much all I did was change the oil and air filter, though it seems I had a lot of crank case pressure so I probably should have changed the PCV valve sooner (did it today). Then I didn't drive it for about a month and a half.

Next time I drove it, it seemed to run okay at first. Then when warmed up it would stall at stops and when I dropped it into D or R. Initially I suspected vacuum leak but the hoses are good, though obviously not quite stock (EGR isn't hooked up, smog pump is gone, etc.). I've found two likely scenarios based on my searching various documents and forums:

This guy seems to say his needle got stuck and it was just getting too much fuel (can I try tapping it with a wrench like I see so often in car shows?). Symptoms are IDENTICAL, down to the high idle in N.
https://www.ford-trucks.com/forums/868397-what-are-the-symptoms-of-a-blown-power-valve.html

Then this thread on this forum suggests bad power valve and Gary gives detailed advice on how to test
http://forum.garysgaragemahal.com/Bought-my-1st-FORD-tp15773p15776.html

I decided I might as well order a new fuel filter too since they're $2, and got a similarly priced filter for the crank case vent hose on the driver side since the old one was... the dirtiest filter in human history, maybe original.

I'm youngish for the carb crowd and don't have much experience with them, though I'm used to working on my own stuff. My last truck was a 93 (RIP) with a 302 and I did quite a bit to that so I'm weirdly better with electronic stuff (have a great story). So I'm definitely trying to learn how to diagnose and treat carbs... have a lot of interest. I think the power valve and needle sound like good places to start, but want to see if anyone has other advice.

Thanks in advance.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

Gary Lewis

Re: Stalling troubleshooting

Administrator

Well, I'm not sure what to call you. "Red" probably applies to the truck. But that's all I have at the moment. So, maybe you could create a signature that not only includes info about your truck but also includes your name? Info on how to do that is in Bullnose Forum/Forum FAQ's.

Yes, you were to post first in the New Members Start Here folder as that will give you the best chance of having seen our guidelines. And since we hold people to them it is important that you have a chance to see them and aren't blind-sided. But, if you can assure us you've seen them then we'll overlook the issue.

But while we are doing the new-member thing, where's home? I ask because we have a map (Bullnose Forum/Member's Map in the menu) and we could add you if we knew your city or zip.

Now for the carb. Yes, you can rap on it, but unless it is a Stromberg 97 it isn't likely that'll work. But I don't think it is a stuck float/needle. I think you may have a vacuum leak. Too much fuel usually causes the engine to bog down rather than running faster at idle. But a vacuum leak almost always causes a high idle.

If you happen to have a 300 six then I'd guess the carb-to-manifold nuts have worked loose. If not, then you may well have a cracked or loose vacuum line.

So, tell us more, please.

Gary, AKA "Gary fellow": Profile

Dad's: '81 F150 Ranger XLT 4x4: Down for restomod: Full-roller "stroked 351M" w/Trick Flow heads & intake, EEC-V SEFI/E4OD/3.50 gears w/Kevlar clutches
Blue: 2015 F150 Platinum 4x4 SuperCrew wearing Blue Jeans & sporting a 3.5L EB & Max Tow
Big Blue: 1985 F250HD 4x4: 460/ZF5/3.55's, D60 w/Ox locker & 10.25 Sterling/Trutrac, Blue Top & Borgeson, & EEC-V MAF/SEFI

red1980F150

Re: Stalling troubleshooting

Thanks Gary.

I did read the guidelines, and went and did so again just to be sure

I went ahead and created a signature, which hopefully I can add to over time to help. I'm in the Springfield Ohio area, 45504.

I bought a vacuum gauge because of this issue (a leak was my first thought too) and it was reading about 21". I think I need to retest though because I'm not 100% sure the choke was completely off. The gauge was at operating temp but had only just gotten there.

I didn't know what I was doing and first and assumed any open hole was a leak so I started capping things that were open, like the bowl vent which had no hose on it. I'm guessing I could go take that off. Obviously I still don't really know what I'm doing, but I started reading the documentation here for most of the day today and that has helped.

The truck still has the stock 2bbl (2150 ?). The vacuum hoses seem fairly healthy, not dry rotted and old, I think the previous owner kept up on it, so I couldn't find an obvious problem with cracked hoses. Though there could be a loose hose, I suppose.

I'm happy to grab some pictures tomorrow. I'm not sure what additional information will help the most so let me know if there's something that would be especially helpful.

If high crank case pressure could be a clue... I have it. It seems most like that's a separate issue, to me, but perhaps worth mentioning. The ported vacuum switch also has no caps and nothing attached to it, I found that earlier today.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

ArdWrknTrk

Re: Stalling troubleshooting

Administrator

High crankcase pressure would explain an oily vent filter.
Are you sure the line between the PCV check valve and the intake manifold is clear?
That seems like a lot of blow by.

Does your truck have a tach?
When you say you have a high idle, but it's just gotten up to temp, perhaps the carb is hung up on the fast idle cam?
It couldn't hurt to examine/clean all those external linkages.

A blown Powervalve usually has a truck struggling at low rpm's and clearing up as the revs increase.
Also common is bucking and popping on deceleration.

Is the EGR vacuum line capped off or is the EGR actually missing and a plate in its place?
An EGR that's stuck open a little could cause a stall at idle when the transmission is engaged.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Stalling troubleshooting

Administrator

In reply to this post by red1980F150

Jim is right on all points.

As for the vacuum gauge, it really won't show that you have a vacuum. Typically a vacuum leak makes the RPM go up and that makes the vacuum reading go up. But having the fast idle cam still on due to the choke being on or the linkage stuck can up the idle as well.

Yes, you should have a 2150 so you can read that documentation if you haven't.

And, you are now on the map.

Gary, AKA "Gary fellow": Profile

red1980F150

Re: Stalling troubleshooting

This post was updated on .

In reply to this post by ArdWrknTrk

Thanks Jim, great idea to check the line for a clog, I might never have thought of that. I checked it after work and it was clear, so no dice there. I do have too much blow by though, I'm hoping it's something fixable and not more severe, but I don't remember the truck leaking at all when I first got it... which has changed significantly.

The truck doesn't have a tach or an oil pressure gauge, which is unfortunate given the current troubleshooting (not coincidentally, I bought a set of gauges last night! - summit racing has a really good deal on the intellitronix gauges ).

So estimating a high idle is totally by ear, but fairly obvious in this case. I'll look at the documentation to make sure know what I'm looking for and check out those linkages. The one thing I can say is that when the choke is on the truck never stalls, the problem only comes about when it's warmed up and the choke is off.

The EGR is just capped off, it's still present. Actually, until I capped it yesterday it was just sitting with no hose or cap. What do you guys think about removing it? I've seen the arguments for using it to cool the charge, not sure if it matters on these old engines... plus mine could have already been unhooked for decades at this point.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

Gary Lewis

Re: Stalling troubleshooting

Administrator

Still sounds like it could be a vacuum leak. You may be a good candidate for the smoke test. Read here: http://forum.garysgaragemahal.com/Vacuum-leak-detection-effective-and-inexpensive-td11511.html. That will usually find vacuum leaks that you might not find another way.

But you can also spray brake or carb cleaner around in suspect areas. If there's a vacuum leak the cleaner gets sucked in and burned, which speeds the engine up briefly. But be away that the cleaner can melt paint, so be careful.

On the EGR, when they work they are good. When they don't they are bad. But you can't just block the EGR valve off and not have other problems. The inert gas slows the combustion process so when the EGR valve is supposed to be open the ignition advanced significantly to get the final combustion to be at the right time. So if you disable the EGR you should re-curve the distributor or you can have pinging.

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Stalling troubleshooting

Administrator

In reply to this post by red1980F150

I think you need a regular carb spacer because you likely have a leak there.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

red1980F150

Re: Stalling troubleshooting

This post was updated on .

In reply to this post by Gary Lewis

Yeah, this all make sense. Just learning what I have and thinking it through... since the throttle is closed at idle and that prevents air from getting in, of course a leak would speed up the idle because extra air is getting past the throttle blades, right? Would the stalling at stops then be because there isn't enough vacuum left to adjust the timing correctly?

The EGR comments make sense too. I guess it might be interesting to hook a line up to it and see how the truck reacts. I read somewhere yesterday that one can test it's functionality when the truck is running with a brake bleeder vacuum, which I have. I should dig that article up (might be on here?). *Edit - found it - http://www.garysgaragemahal.com/egr-system-description--testing.html

In any case, you have given me some good homework and a few things to try, I very much appreciate it.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

red1980F150

Re: Stalling troubleshooting

In reply to this post by Gary Lewis

Gary Lewis wrote

Still sounds like it could be a vacuum leak. You may be a good candidate for the smoke test. Read here: http://forum.garysgaragemahal.com/Vacuum-leak-detection-effective-and-inexpensive-td11511.html. That will usually find vacuum leaks that you might not find another way.

This is awesome.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

1986F150Six

Re: Stalling troubleshooting

Administrator

red1980F150 wrote

Gary Lewis wrote

Still sounds like it could be a vacuum leak. You may be a good candidate for the smoke test. Read here: http://forum.garysgaragemahal.com/Vacuum-leak-detection-effective-and-inexpensive-td11511.html. That will usually find vacuum leaks that you might not find another way.

This is awesome.

https://www.bing.com/images/search?view=detailV2&ccid=mtcKEBHN&id=93E2C3EF878EA7098AE7934CD9A4CBED7D980CCB&thid=OIP.mtcKEBHNmfDdWI06LMY-bAHaIY&mediaurl=https%3a%2f%2fth.bing.com%2fth%2fid%2fR9ad70a1011cd99f0dd588d3a2cc63e6c%3frik%3dywyYfe3LpNlMkw%26riu%3dhttp%253a%252f%252f2.bp.blogspot.com%252f-nuzgAQh-eBw%252fVdOIgseICSI%252fAAAAAAAAQqU%252fsKyWK2sH6Z0%252fs1600%252fcigar-smiley.png%26ehk%3daK6j%252fbF%252bNZ%252bd%252f%252f8l8djyLHLewL9fyvvm12cftmcYZGE%253d%26risl%3d%26pid%3dImgRaw&exph=600&expw=530&q=smoking+cigar+emoji&simid=608003001331879631&ck=2AF8480775B32A2DE19BD912CAB485BD&selectedIndex=0&FORM=IRPRST&idpp=overlayview&ajaxhist=0

Gary Lewis

Re: Stalling troubleshooting

Administrator

This?

Gary, AKA "Gary fellow": Profile

1986F150Six

Re: Stalling troubleshooting

Administrator

Yes, thanks!

Gary Lewis

Re: Stalling troubleshooting

Administrator

Fixed it.

Gary, AKA "Gary fellow": Profile

red1980F150

Re: Stalling troubleshooting

Alright, didn't have a chance to do much during the week.

I changed the PCV valve on Sunday and temporarily took out the clogged crankcase filter for the return gas. During the week the truck stopped bogging as much as stops and would actually stay running. Still doesn't seem quite normal but it's not that bad.

Popped in a new fuel filter this morning (they're cheap and the old one looked to be very old) and a new crankcase filter. Took me 747 million years to get it started because I flooded the engine by accident, bottle feeding, and didn't get the new filter primed (is it possible to get your finger in the carb and lift up the float? How do you guys get the pump to run?). These changes made no real difference, as expected.

I sprayed carb cleaner around the base of the carb and couldn't get any RPM increase, so I may move to a smoke test. In the meantime, I'm probably going to do a compression test as well... she's pumping blow by out of the valve cover cap at idle, with the cap on. I can upload a video even. So I'm thinking the engine may be a little hurt, though it still runs pretty well. In fact, I drove it all week and it seems to be getting better every day.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

Gary Lewis

Re: Stalling troubleshooting

Administrator

Not sure I understand. You asked how to get the pump to run, but isn't it a mechanical pump? I didn't think the electric pumps were used in 1980. What am I missing?

If it is running better each day then maybe you just need to drive it more? Change the oil and maybe it'll clean up?

Gary, AKA "Gary fellow": Profile

ArdWrknTrk

Re: Stalling troubleshooting

Administrator

In reply to this post by red1980F150

You can host a video on YouTube, or somewhere else and imbued it here but you can't upload a video to the forum.

I imagine the rings are loosening up and starting to seal.
A little ATF or Marvel Mystery Oil in the cylinders can help get deposits free.
You really need a leakdown test to determine how much is getting by the rings.

All you have to do is fill the bowl(s) to get the truck to run.
I use an irrigation syringe to fill through the vent tubes sticking up out of the edge of the carb neck.
If you have a mechanical pump like me that should be enough to get the system primed and running.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

red1980F150

Re: Stalling troubleshooting

In reply to this post by Gary Lewis

Oh you're not missing anything, I am

Jim got me straightened out, after thinking about it I know exactly what I did wrong and I think he read between the lines and knew.

I think I will keep driving it more, probably all of this coming week too. I don't know how much she sat, but it would make sense if it was quite a lot. My old boss's wife bought it new in 1980 and she passed some time ago. He gave it to me because I told him I'd try to both use it and take care of it. Anyway, at his age I doubt either of them used it much in the past 5 or 10 years. The oil that came out of it when I picked it up in May looked really old and wasn't very viscous.

I'm starting to compile a larger and larger list of things I need/want to do to it. Do you guys think that list and progress updates with pictures would be a good thread for the forum?

In related news, I got my new shop manual in the mail today.

John

Red 1980 F150 Custom - Standard cab, long bed, 4WD
302 v8, Auto transmission
Almost completely stock, quite clean but not perfect.

ArdWrknTrk

Re: Stalling troubleshooting

Administrator

John,
Pics and progress is always a good thing.

If you've found the oil is thin you should make sure the fuel pump diaphragm is not leaking into the crankcase!

This isn't uncommon and will cause your symptoms.
If you see that the oil level is rising, you'll know for sure what the problem is.

Gasoline is a poor lubricant.

Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.

Gary Lewis

Re: Stalling troubleshooting

Administrator

Yes, make sure you check the oil for gas in it. Smell the oil. And, as Jim said, if the level goes up you have a problem!

The best thing you can do for the engine is to keep clean oil in it and drive it. Some advocate using kerosene or ATF as the last quart in an oil change, but I wouldn't recommend that. One of our guys, David/1986F150Six, had the sludge come free in his engine and it plugged up the oil pickup in the pan and he lost oil pressure. That wasn't from using kerosene or ATF, but it was a sludged up engine and it all came free suddenly.

So you want it to come free over time and be caught by the filter. Use a good quality oil and filter and take long drives to get everything good and warm. And then change the oil as it starts looking dirty.

Gary, AKA "Gary fellow": Profile