Engine suddenly dies...

I have about 5,000 miles on my VX since my rebuild. It had been running flawlessly until last week. The wife and I went out to dinner and was sitting at a red light and just die. No spitting or sputtering just died like the key was shut off. It fired right up and ran as smooth as ever. I took a road trip over the weekend to watch the grand kids play t-ball. It ran fine on the trip out (500 miles) but on the way home the truck suddenly jerked like it shut down but only for a second and continued just fine for a nother 100 or so miles and did it again. The wife drove it to town after I got home and told me it shut off on her at a stop sign. When it shuts down it is like the switch has been flipped no spitting or sputtering very sudden and complete but always fires right up. No check engine light or anything like that at the moment.

I ponder if it could be the fuel pump as that is about one of the only things I didn't change. I also ponder if it is something electrical due to how quickly it shuts down. Anyone experience this???

my vx would just die like that when i first got it, fuel pressure regulator and fuel filter were replaced and it was fine.

when the engine was rebuilt, what torque did you use for the intake manifold? tech manual says 19ft-lbs but then a tech bullitain came out and changed that number to 13 because the gaskets were squeezing out and causing vacum leaks

I am not sure what specs were used to torque the intake. I had the machine shop assemble the engine, a decision I later regretted. I replaced the fuel filter before I started driving it.

If you think its the fuel pump, check the fuel rail next time it shuts itself down. If the rail has pressure its not the fuel pump.

Couldn't be something as simple as a loose battery terminal connection could it? I experienced the very same thing recently with my car. Don't know if the changing ambient temps of the seasons changing from winter to spring may have had anything to do with it, but that's when it happened. Cleaned both terminals and posts, made sure both terminals were seated as far down on both posts as possible, then tightened and haven't had the problem again.

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Originally Posted by Y33TREKker

Couldn't be something as simple as a loose battery terminal connection could it? I experienced the very same thing recently with my car. Don't know if the changing ambient temps of the seasons changing from winter to spring may have had anything to do with it, but that's when it happened. Cleaned both terminals and posts, made sure both terminals were seated as far down on both posts as possible, then tightened and haven't had the problem again.

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ah...good one...

I vote that one. Easy to fix too.

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Originally Posted by JAMAS

ah...good one...

I vote that one. Easy to fix too.

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yea, but loose terminals will cause hard to start too...
and when engine is running alternator will keep electricity to flow, even with battery disconnected....:confused:

Unless the alt is malfunctioning too. The full wave bridge rectifier circuit (voltage regulator) diodes in the alternator can die one by one, as they die, the alternator will give power, but not good usable DC power that the vehicle needs. So your alt can limp along apparently OK enough to charge the battery, keep the vehicle running etc, until the third diode blows then you wont have jack for usable DC power.

If the rectifier circuit is otherwise damaged, and functioning intermittently that can also cause probs like this. Easy fix is to check the battery/cables and terminals as previously mentioned. Then check your alternator. You may find that the alt has blown a couple diodes. Or that they are functioning intermittently. Either way, the fix for that is to replace the alternator as the rectifier circuit (voltage regulator) is built into the alternator and not considered a replaceable part in most modern vehicles.

Cables are clean and tight. I double checked the tightness.... everything was thoroughly cleaned during the rebuild. I will see about having the alt checked to be on the safe side.

check the windshield washer fluid. Perhaps it needs filling or maybe a flush and replace with synthetic...

:)

I once had a similar problem on a different car and it was the ignition suddenly cutting out, eventually if failed completely making the problem easy to find.

This is the same problem I was having in Moab last year. Replaced the them filter, but that wasn't the problem. The fuel pump was working, but just barely. I don't remember the exact numbers, but Isuzu specs said the pressure should be something like 40psi and I was getting more like 15psi. Replaced the pump and that solved the problem. No more stalling.

Well, at least we've got it narrowed down to either a fuel or electrical problem. :bwgy:

Fuel pressure shouldn't be that hard to check, but given the number of connections in engine harnesses and the engine bay in general, I still wouldn't discount the possibility of a ground connection that didn't get tightened properly during the rebuild/reinstall process. (For example, what about the other ends of the (+) and (-) battery cables?) 5000 miles is enough time for something that wasn't tightened properly to have vibrated loose just enough to start causing intermittent problems like this.

In my profession we have an axiom "common things occur commonly". I would replace the fuel filter.

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Originally Posted by etlsport

my vx would just die like that when i first got it, fuel pressure regulator and fuel filter were replaced and it was fine.

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What he said. I had the same problem. Driving along, slow down to turn in to a parking lot and thud, engine dies. Hit the starter and it would fire right back up without so much as a sputter. I did the fuel filter first but eventually got around to the pressure regulator and that did the trick. Not a problem since.

Change the fuel filter and clean the MAF.

The MAF could be bad or just dirty. Also check the EGR valve.

I had this exact problem a few weeks ago.

Then I had a high idle problem and changed the AIC.

Jon

It could also be a crank or cam sensor. Check the connections. If they fail or lose connection they shut down the ignition to stop damage. It will be like you just shut the key off. Not always but usually fuel will give you some sputtering even with fuel injection. EGR causes massive vacuum leak making high idle.