Total shut-down while driving - Page 2

Makalu1 · 03-03-2018, 11:32 AM

Mike Palmer Auto in Salt Lake did the work. They replaced the idle air control valve, replaced the fuel filter and the plugs. I hope that did the trick. Palmer fixed our AC issues earlier so we may have found our go-to SMB shop in town. Thanks for the suggestions everyone.

TomsBeast · 03-03-2018, 02:04 PM

Intermittent problems can be a PITA to track down, I hope the IAC did the trick. I had a new 1990 Nissan truck where you'd be cruising along at 65mph, then it would stop firing for about 3 engine revolutions, then go back to running fine. Happened once every 3 weeks, then once a week, then once a day. Eventually the IAC was replaced under warranty, and the problem went away for good.

arctictraveller · 03-03-2018, 02:17 PM

Idle air control, Hummmm. I'm pretty ignorant about the sensors on the 5.4, possibly because they rarely seem to fail and no one ever talks about them. Perhaps I'll add an IAC to my spare parts collection. Hopefully, this fixes your problem, be sure to follow up and let us know, but can anyone explain why the IAC would lead to a total shutdown?

JWA · 03-04-2018, 04:23 AM

Quote:

Originally Posted by arctictraveller

Idle air control, Hummmm. I'm pretty ignorant about the sensors on the 5.4, possibly because they rarely seem to fail and no one ever talks about them. Perhaps I'll add an IAC to my spare parts collection. Hopefully, this fixes your problem, be sure to follow up and let us know, but can anyone explain why the IAC would lead to a total shutdown?

Hmmm----not sure why an IAC would/could cause a complete shut down like Makalu describes. I had one go funky on me, engine ran fine at all speeds/conditions except idling of course.

Also IIRC the IAC's were gone by '99 or '00, before Makalu's chassis was built.

Interesting for certain...........

Makalu1 · 03-04-2018, 10:49 AM

"Interesting" alright, if you're saying this part was gone before my van was built then we're talking fraud here, right? Which I tend to doubt, but... Like Arctictraveller, I too wondered how/why these parts would lead to a total shutdown of ALL the electronics- everything. But I don't understand how all these parts work together so I could be easy to sucker.

So here's what I (think I) know-

The original owner warned us about an occasional hesitation that usually but very infrequently and unpredictably occurs after the vehicle's warmed up a while and happens when accelerating from a stop, or when you're going slow and starting to speed up, like in an intersection or entering an onramp. He was right. If we're on the road a couple of days it might happen once or twice- or not at all. Previous owner said his mechanics couldn't solve it either.

That problem got really severe last August while running vehicle hard, got a check engine light and the hesitation turned into a full blown quit. A Ford place in Moab cleaned the mass airflow sensor, replaced air filter and "cleaned senso". The vehicle worked okay after that, but the occasional hesitation returned pretty soon. None of these previous issues were accompanied by a total system shutdown.

I understand that tracing a problem when the problem isn't occurring can make diagnosis difficult. But this is particularly irritating since the shutdown was so random and we use the vehicle as intended- out in the boonies!

Any more suggestions/comments are most welcome. Meantime I plan to visit Palmer again this week and seek a more detailed explanation, we were a bit rushed when I picked up the van from the shop.

arctictraveller · 03-04-2018, 12:36 PM

A check engine light should have set a code, did they tell you what it was? As for hesitation upon starting up after a stop, that's exactly what mine was doing. As I said, fuel pump. At a minimum, I'd carrry a spare. When my second one went out, I was stranded in Barstow while the shop had to order one. At least if you have one with you, it's only a couple hour job to change, rather than possibly having to wait for one to arrive. They fail with alarming frequency, often times with zero notice, but more often you get some advance notice such as the symptons you are experincing. Check the fuel pressure at the fuel rail, if it's at or below minimum, consider a new pump.

Makalu1 · 03-04-2018, 01:53 PM

Arctictraveller, I think the code setting got reset before the shop who did the MAS work, long story. I guess I should have asked Palmer Auto if/what the code told them. Boy do I wish there was a better learning curve on this for me! So with your fuel pump issue, you got hesitation, but did you ever experience a total shutdown that included electric?

arctictraveller · 03-04-2018, 02:22 PM

What do you mean by "included electric"? If you mean, all gauges, lights, radio etc, then, no that didn't happen, only the motor shut down just as you described. If your loosing all electrical through out the van, check the battery cables carefully on both ends, and the power supply wires to the fuse / junction boxes etc as it sounds like there is a common feed point for all those items that quit, including the fuel pump.

MadScience · 03-05-2018, 12:17 AM

FWIW, my first thought was also, as carringb pointed out, a poorly connected battery. I've experienced this with my van, and it feels a lot like either fuel or spark just faded away. At the same time the lights dim.

My initial theory was a dead battery caused by a failed alternator. In my case it was just a poorly connected battery clamp from the last time a shop had the van. I wouldn't be surprised if the same symptoms could be induced with a bad connection on other points of that circuit though. -- My daily driver has a known issue where the ground strap from the engine to the chassis can lead to situations like this.

Also, you'll likely be happier if you just pick up something that'll read codes for you. This can be a $15 OBD to bluetooth or wifi dongle these days. That way you'll have a record of a code before you hand the van to a shop. -- In theory a good shop will root-cause and apply the correct fix, but some problems are hard to debug, and some shops are better/more committed than others. At the end of the day, you're the one that has to live with the van.

That said, I wouldn't knock replacing the IAC, but I also don't feel like there's enough evidence to relieve concerns about something else going wrong. If you were on the throttle at all when it died, then I doubt it was on the scene.

FWIW, I do suspect your van has an IAC, unless it's a 3 valve, which I don't think ever made it into the vans, but I don't know as much about the v8, so I might be mistaken here

bet on black · 03-06-2018, 03:02 PM

i don't see how the iac would make the engine die under a load. it only functions at idle. if it gets stuck open, you can hear it, as it makes a howling noise, but the truck will still run fine, but won't idle right. also ford used the iac to control idle speed on every 2v 5.4 i've seen. don't think it was phased out until the 3v motors, which were also drive-by-wire.