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Engine dies out

collinbrewer

Sr. Member
Joined
Jan 23, 2007
Messages
529
Loc.
Austin
I've been driving my Bronco for about 6 months now after a complete frame up with no major issues. I'm running a 5.0 EFI from a '91 Mustang.

On my way home from work the other day I was cruising at 60mph and she just died, cold turkey. No warning, no sputter, just done.

I coasted into a parking lot and jiggled everything I could think of and found a *slightly* loose wire on the ignition switch, tightened it up, turned the key and she fired right up... Finished my drive home.

The following day: same story on my way to work, this time there was nothing to tighten... looked everything over and found nothing. Turned they key, she fired right up... Finished my drive to work.

Same day on my way home: same old story except this time, I coasted to a stop, turned off the key, and on a whim, ate sunflower seeds until 5 minutes had passed. Turned the key, she fired right up... Finished my drive home.

From that, it seems pretty clear that it's a heat issue and we're having 90º+ days here in Texas.

My only thought is that my computer is overheating and shutting off?

Thanks in advance.
 

Bronco Junkie

So Cal Broncos
Joined
Feb 29, 2012
Messages
3,232
I'm no expert by any means....but if it was heat...why would it fire right back up after just a few minutes? Usually, a motor will get hotter in the few miuntes after shut off when the cooling system is also off and there is no air flow. Just throwing that out there.
 

jw0747

Contributor
Bronco Guru
Joined
Nov 22, 2006
Messages
2,434
Loc.
San Antonio, TX
my problem like that was overheated fuel pump. where is your f.p. mounted external on frame or internal fuel tank?
 
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collinbrewer

collinbrewer

Sr. Member
Joined
Jan 23, 2007
Messages
529
Loc.
Austin
70_Steve: Any way to test this?

Bronco Junkie: I was thinking more along the lines of the computer getting too hot, it would cool down very quickly.

jw0747: FP is in-tank though my fuel level is low, I'll try filling up and seeing if that makes a difference.

banana: FP is in-tank and less than a year old, also runs fine the when it's not dying. What would be clogging the exhaust and how would I check it?
 

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
70_Steve: Any way to test this?
No practicle way I know of to test a heat sensitive TFI. Especially one that seems to "heal" it's self on power cycle. If it would stay broke for a little while, I'd suggest pulling the SPOUT connector, an see if the engine will fire. Other than that you're left with shotgunning.

Way, way back when, my (ex)wife had a 1972 Chebby Nova, 307 with points ignition. After a couple years I decided to upgrade to electronic ignition using a kit that Mallory came out with. Ran great for about a year. Then my wife started telling me that the engine would die. She'd coast over to the side of the road, try to restart, it would restart every time, and she'd continue driving. She said it got to the point where she would feel the engine die, pop the tranny into Neutral, restart the engine on the fly, drop it back down in Drive and continue on. I replace the eletronic ignition with the old points and never had another problem.

Point being, intermittant electronic problems are a bitch.
 
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collinbrewer

collinbrewer

Sr. Member
Joined
Jan 23, 2007
Messages
529
Loc.
Austin
You're not lying 70_Steve, I love the line, "If it would stay broke for a little while"... so true. I have to risk my life just to see if I can get it to happen again.

I'll report my findings.
 
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collinbrewer

collinbrewer

Sr. Member
Joined
Jan 23, 2007
Messages
529
Loc.
Austin
Still fighting this booger!

I've replaced the coil, coated my headers and built a remote TFI wiring harness and am still having the issue.

That said, I haven't had the issue happen while driving down the road, but after she sits for 5-10 minutes after a warm drive, she wont start back up for a half hour or so. After that, she'll fire right up. Grr... Help!
 

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
That said, I haven't had the issue happen while driving down the road, but after she sits for 5-10 minutes after a warm drive, she wont start back up for a half hour or so. After that, she'll fire right up. Grr... Help!
What are you missing during that half hour? Spark? Fuel?
 
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collinbrewer

collinbrewer

Sr. Member
Joined
Jan 23, 2007
Messages
529
Loc.
Austin
At this point, I can't say with any certainty...

What I can say is that while she's throwing her fit, I've hooked up my timing light to both the coil wire and #1 and am getting a signal, and I've also pulled #1 and watched it spark(although I would describe it as "puny", need to compare it to when it's not in a fit). And I do have *some* pressure at the fuel rail, though I don't have a pressure gauge so I can't say how much pressure.
 

70_Steve

Old Guy
Joined
Dec 13, 2002
Messages
8,317
At this point, I can't say with any certainty...

What I can say is that while she's throwing her fit, I've hooked up my timing light to both the coil wire and #1 and am getting a signal, and I've also pulled #1 and watched it spark(although I would describe it as "puny", need to compare it to when it's not in a fit). And I do have *some* pressure at the fuel rail, though I don't have a pressure gauge so I can't say how much pressure.
Originally, my thought was a leaking injector or six, flooding the engine. But a leaking injector would only affect one cylinder...maybe...

Have you tried starting it like it's flooded when it acts up? Supposedly, when starting, and the EEC sees full throttle, it cuts out the injectors to aid in clearing a flooding condition.
 

Viperwolf1

Contributor
electron whisperer
Joined
Aug 23, 2007
Messages
24,316
You need a fuel pressure gauge. I don't suppose you've pulled the codes?
 
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collinbrewer

collinbrewer

Sr. Member
Joined
Jan 23, 2007
Messages
529
Loc.
Austin
NYLES: I haven't replaced the TFI, it's <5000 miles old, I also had it tested at the auto parts store and it tested fine, however my next step is to replace it anyways.

Viperwolf: I'll get a fuel pressure gauge and verify. Pulled the codes, nothing to speak of.

70_Steve: I'll try that later today and report back.
 
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