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Engine Stalling

jlmclean

11
0
Need some advice from you die hard Ford mechanics. Got an '87 F150 with a 302 EFI engine. Not every time but almost, when you first crank up, it will crank then die, crank it again and sometimes it will run fine and then other times it will keep dieing. On it's worst times, you can be driving and go to stop and let off the throttle and mash in the clutch, it dies. On occassion, it runs perfect, idles good and all. I recently put new valve cover gaskets on and when I removed the plenium, it was loose and the gasket was definately leaking. I really thought that would be my problem but after putting it back together, it ran decent for a day or so and then started dieing again. Yesterday, I drove it about 1/4 mile and it ran good except for dieing on the initial startup. I let it sit for a couple hours and then drove it about 5 miles and it would not idle at all. I let it sit for about 30 minutes, cranked up and drove back home and it ran perfect.
Thanks for any suggestions.
 
Truckin4life

Truckin4life

Texas Chapter Leader
9,037
287
San Antonio, Texas
Is it a sputter and die or is it just a instant kill?
Any chugging or anything before it dies, hard to start after it dies?
Does it start right up after it dies or do you have to wait a while....
 

Alvin in AZ

1,330
46
Venta de la Mesilla
Yeah, I gotta suggestion for ya... ;)

Amazon.com...
Equus 3143 Ford Code Reader 1981-1995 Ford OBDi
~$15

There are codes that don't turn on the CEL and that thing beats the crap
outta countin' them dangged flashes, IMO. LOL :)

It's not quick like an OBDii reader, the thing just counts the flashes for you,
then displays the numbers, so it takes some time because the OBDi is slow
to give out it's information.

The time saved and frustration saved, tho, is worth ~$15 to me, YMMV?
Try, it you might like it? :)

Anybody got an expensive OBDi reader that does more, and actually worth
the money? :)

Alvin in AZ
 
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jlmclean

11
0
Trukin4life
It doesn't really splutter but it doesn't cut off as quick as it would if you turned the ignition switch off. Matter of fact, sometimes it will slow way down and you'll think it's going to die and then it'll pick back up and run OK. It has on occassion sat there and speed up, slow down, speed up, slow down, just over and over. The best I can explain it is like when you're driving and say you stop at a stop sign and it dies, you know the EFI doesn't idle down as quick as a carburetor anyway, as it idles down it forgets to stop when it gets down around 800 RPM and just keeps getting slower at that rate until it stops. As for restarting, just as soon as you turn the key, it's running again. I think you've hit on something there because it does slow down instead of just stopping like you turned it off. I've got a code reader, just haven't used it yet. Guess I need to get it out and see what this thing will tell me.
Thanks
Flairside_Thunder
Thanks for the site. I've been looking for a site like that. Should be real helpful
 
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Old_Paint

Old_Paint

Old guy with old cars
225
29
Alabama
Yeah, sounding like a sticky IAC to me. Take it off, drop it in a bucket of Seafoam overnight, then steal your wife's toothbrush to finish cleaning it the next morning. (Just make sure she has a spare).
 

D427COBRA

36
2
I have a Thunderbird that was doing that. It turned out to be the fuel pump. Do you have a press gauge? You can put that on to make sure you're getting gas.
 

NeXtras

973
11
Sounds more like IAC than a Fuel Pump

" sometimes it will slow way down and you'll think it's going to die and then it'll pick back up "

that right there tells me IAC.. mine did the same thing, particularly on colder starts, sounded like it was cammed out, was kinda cool lol.. then it got worse.. same thing, would crank, fire then die.. that was not a fun ride to my work when that happened.... IAC's are about $50 from Ford if cleaning it doesnt work
 

jlmclean

11
0
I haven't deserted you all. Been in a place ,almost heaven, cell phone didn't work and no computer access this weekend (still had work to do though). Back at home now and hopefully I can work on the truck some this week. I'm definately going to clean the IAC and see what happens. That sounds like it's the problem but as I'm sure you all know, what we think is not always the answer, these things have a mind of their own. I'll definately keep you posted.

NeXtras: Good looking truck

Thanks to all
Jerry
 
Old_Paint

Old_Paint

Old guy with old cars
225
29
Alabama
More often than not, a surging idle like that is caused by either a sticking IAC, or, an intake leak.

Take the intake hoses loose at the throttle body, and open the throttle to WOT. Look at the backs of the butterflies. If you see a buncha gunk built up on there, chances are the IAC is crudded too. If it's really bad, probably wouldn't hurt to go ahead and snatch the throttle body off and clean the whole thing. No better time to put on a new TPS while you're there. Throttle body has to come off for a TPS, so if you anticipate replacing it, do it the first time you pull the throttle body off. Shine a flash light into the intake plenum, and see how much crud you can see up in there.

One other thing that can cause a surging idle is a sticking PCV, which will look like a big vacuum leak. If you want to verify it isn't a vacuum leak, disconnect EVERYTHING from the vacuum tree on the plenum except the FPR and the MAP. Crank the engine and see if it idles smooth. If it does, hook the hoses back up one at a time until it idles crappy again. That'll point you right at what's leaking. If it still idles crappy, take a plumber's torch (unlit) and point it all around the base of the plenum. If it's leaking there, when you find the leak, it will smooth right out and idle very nicely, if a little fast. The beauty of the propane is you won't have any flammable liquids to ignite on your engine, and even if something does ignite it, it's a quick blue flash and it's over. Nothing to keep burning.
If you don't have one, get:
Vacuum gauge
Fuel Pressure gauge
Hand Vacuum pump
Compression gauge

These four little tools, at decent quality, will run you just over $100. They will probably save you 10X that if you're using a dealer for your work. Don't ask me how I know. I'd like to have my $1000 back, though, because I wound up fixing my own truck.
 

Alvin in AZ

1,330
46
Venta de la Mesilla
Old_Paint wrote:
>If it's really bad, probably wouldn't hurt to go ahead and
>snatch the throttle body off and clean the whole thing.

Ok, mine has a label right on it saying -not- to clean it.
I've read why...

It has something to do with a coating the factory puts
on them and they are afraid you'll remove it and mess up
their precious little settings. ;)

Ok, so I'm fiNguring WD-Dummy (Stoddard's solvent)
won't remove any coating that the gasoline vapors etc
won't remove.

What do you guys think? :)

Am I dumber than a can of WD-40? :/

Alvin in AZ
ps- If you don't like WD-40, how about one of them
water-soluble-oils that's made from citrus peels? :)
 
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Alvin in AZ

1,330
46
Venta de la Mesilla

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