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Discussion Starter #1
OK, I have an 86 with an EFI 302. Yesterday I was moving it off my driveway so I could shovel the snow., so I used my remote start to fire it up. It fired right up (as always) and then died right after (not usual). The remote start automaticly restarts it if it stalls... but it wouldnt fire, it just kept turning it over. So I tried starting it manually. It didnt fire right away, so I pumped the gas a bit and it fired up. I backed it off my driveway and shut it off. About an hour later, it fired up just fine, and I drove it around with zero problems. So I figured it was just a fluke thing.

Then this morning I turned the key, but it wouldnt fire. I tried pumping the gas, but that didnt work either. Then I noticed the fuel pump wasnt making the familiar whiring sound when I turned the key. I checked the "cut-off" switch and that didnt seem to be the problem, and I tried banging on the gas tank with a crowbar....because sometimes hitting shit helps.... but it didnt. So I just sat in the truck and cycled the key a few times and I eventually heard the pump prime, and the truck fired right up and ran with out problem, and the pump primes every time I turn the key. I did notice that there is also an electical "click" sound that happends along with the whirring sound. Im not sure if its supposed to do that or not?

I did some searching and read something about a "fuel pump relay" and wasnt sure if that could be the problem or not. Do you guys have any ideas?
 

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pumping the pedal on EFI does not do anything like injecting fuel like a carb was designed to do.

check to see if the pump is getting power, if so then the pump probably died.
 

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Discussion Starter #3
If the pump died, why is it still starting and running? I would have figured that once the pump died, it would stay dead

As far as pumping the gas on EFI, Ive had it work before when I couldnt get it started. I cant say why it worked, though. I have heard that its bad for EFI engines to pump the gas.
 

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Check fuel filter, it may be getting clogged & then unclogging once petrol begins to flow once the pressure builds up alot.but at strat up it may take a while to actually get that pressure up there in the 1st 20-30 secs
 

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Intermittent problems are a pain.

ON my '90 bronco the fuel pump relay is located on the driver's side just behind the air filter box. They are inexpensive. I don't know how to test them.

It is my understanding the fuel pumps can get a little flaky and not always go all at once. Also on your bronc i believe that there are two fuel pumps, one in the tank, and one on the rail. One is a high pressure, the other low pressure. You would probably do well to get your self a pressure guage and do a fuel pressure test.

IF it passes keep the tool handy, and the next time she doesn't start test it again. Ofcourse there are a number of reasons why it won't start, but this will help you to figure out if it is really a fuel problem or not.

You may also want to check your wiring diagrams for your year truck, and make sure that the grounds that pertain to the fuel pumps are clean and tight.
Good luck
joe
 

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Intermittent problems are a pain.

ON my '90 bronco the fuel pump relay is located on the driver's side just behind the air filter box. They are inexpensive. I don't know how to test them.

It is my understanding the fuel pumps can get a little flaky and not always go all at once. Also on your bronc i believe that there are two fuel pumps, one in the tank, and one on the rail. One is a high pressure, the other low pressure. You would probably do well to get your self a pressure guage and do a fuel pressure test.

IF it passes keep the tool handy, and the next time she doesn't start test it again. Ofcourse there are a number of reasons why it won't start, but this will help you to figure out if it is really a fuel problem or not.

You may also want to check your wiring diagrams for your year truck, and make sure that the grounds that pertain to the fuel pumps are clean and tight.
Good luck
joe
X2

Diagnosing the problem is always the best way to go. If you start throwing parts at it, you are never quite sure you have found the problem.

Cheers

Steve
 

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Discussion Starter #7
Well it was starting and running fine for the last 5 days, but its doing it again. I started it with remote start, it fired for a split second, then died. That sounds like a fuel issue to me. The pump just isnt priming anymore. Last time I started/drove it the pump primed and ran fine, so Im just hoping that its the relay thing. I never did check the fuel preasure with a preasure gauge because A) Im not sure how to; And B) its way to cold to be crawling around in a snow drift trying learn.

I have both an 87 f150 with a 302, as well as an 86 bronco II that I can pull parts off of. Since its really, really cold, and I have no garage, I was thinking Id try changing the relay out with one of the relays from the trucks mentioned above (How expensive are they? If they are cheap, Ill just buy one). Would the relays be interchangable? Im also curious if anyone has a picture of the relay so I know what Im looking for, and possibly instruction on how to change them. I do have a Haynes Manual, and I can see the section that talks about this.... but it may as well be in German, because I have NO idea what its talking about, lol. Anyway, Im in the middle of searching, so Ill get back to doing that. Any help would be great.
 

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well, then go ahead and replace the relay. Checking fuel pressure is really easy, and probably easier than guessing at the relay. Until this problem is solved, I'd quit using that remote start.

Fuel pumps die in different manners. They are relatively complex items. I had one just quit on me in the middle of nowhere, but I've also had one slowly die, and exhibit similar symptoms.

Relays can also exhibit the same symptoms you are describing. work now, no work later.

I just helped a neighbor out today with a similar problem. turned out to be a bad ECM fuse. the fusible section had fatigue cracked and was making intermittent contact. No fuel pump prime. Add in corroded battery cables, and a battery with a dead cell. was a fun two hours.

Long story short, DIAGNOSE the problem. I could have guessed for two weeks about the parts, but until I broke out my test meter and fuel pressure gauge, and started DIAGNOSING the problem, I was not solving the problem.

If you are lost reading the haynes, I don't know how to explain any more thoroughly than they do.
 

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you have 2 fuel pumps, if 1 dies it can still run just not very well or long.
You'll need to check both, one in the tank and one one the frame rail
 

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Discussion Starter #10
It was the relay. Popped one in, and it fired right up, ran great... and then I burried it in a snow drift. Life is swell :)
 
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