VX shutting off in the middle of driving

My VX has shutting down in the middle of driving 3 times in the past 2-3 months. My local mechanic and the dealer can't tell me what's wrong. Each instance has been under different circumstances but the engine will shut off while moving and I have to stop and wait a minute before I can start it up again. Trying to fix/ prevent this I have gotten the following work done:
- changed all belts
- changed fuel filter
- fuel system and egr cleaned
- MAF cleaned and O2 sensors replaced
- changed spark plugs
- changed steering pump
- changed water pump (not related)
In reading some posts, I need to get my codes read from the mechanic but I think I remember them saying they got no codes.
Any ideas what might be wrong? I am hoping/ praying that I don't have the engine failures that other have had in the past as it might mean I'll have to get a new vehicle.

So does it start missing or does it just shut off entirely? If it starts running rough, I'd say fuel system (fuel pressure regulator - and a faulty fpr may cause immediate shut-offs too) or ignition, but if it shuts off quickly I'd say some sort of problem with a wiring harness or connector. There are a couple of common areas where people have had problems with the insulation on the factory harnesses rubbing against frame rails and such to the point where bare wires get exposed causing electrical shorts. The fact that it restarts after such a short time sounds like a faulty fpr to me though.

My VX shuts off entirely without a warning of running rough. Might the fuel pressure regulator also be the cause of a recent and substantial loss in mileage?

While you are checking that, I would start the truck, go into the engine compartment and move around all the wiring harnesses you can reach. Just a thought.

Demons!!

I'm sorry for your problem! You hear about these sorts of problems occasionally. An old boss of mine had it happen in his Jeep Cherokee. In his case, it was a top-dead-center sensor (I think - this was like 15 years ago...) that was faulty, but it took like 2 years of "repairs" to figure it out.

kobie,

I'm with Anita. I seem to remember this happening to a couple of other people and they found out that one of their wiring harnesses had worn through and it was causing a short that would stop the engine. Check the wiring harnesses that go through the firewall first. Hopefully someone who had this problem will chime in.

Quote:

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Originally Posted by kobie

My VX shuts off entirely without a warning of running rough. Might the fuel pressure regulator also be the cause of a recent and substantial loss in mileage?

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Yes, those two have been listed as cause and effect in the past by a few owners here.

Sorry if I sound like a jerk, but have you checked the connections to the battery (goes in line with checking all wirign harnesses)?

I had a problem where my car died (old studebaker), and it turned out that the wires were not securely attached to the battery. tightened them up, and it ran like a top.

Good luck!

Creeg;
I have checked the battery terminals recently (they're secure) but have been through 3-4 batteries since I've had the VX... I still haven't been able to figure out why that was either.

My VX will do the same thing. But, it never totally stops. I'll be driving and it feels like everything goes dead, throws you forward in the seat, then it picks up like nothing happened. I am trying to pay attention to what is going on when it happens, does the radio turn off, lights dim, what does the dash do, does the steering go out, things like that. It has only happened once where it killed the engin and it required re-cranking, but only because I was in the middle of cranking it, I had just released the key from start to run, and shifted into drive, and it killed the motor. It restarted right away.

I have some quesitons about your description. It dies and you have to coast to the side of the road, right? Will it restart immediatly, or is everything dead? What does the dash say? Is the radio on and will the lights work? I am just wondering if it is a engine thing, or an electrical issue.

D.W.

i vote fuel system.. try replacing the fuel filter and fuel pressure regulator (in that order)

i had my vx at about 75 on the Atlantic City expressway.. let off the gas for a second.. got back on the gas and couldnt get over like 1500-2000 rpms (dont remember exactly).. got it pulled over.. turned it off.. looked under the hood.. didnt see anything out of the ordinary.. so started it back up... ran like a champ.. i replaced the fuel filter a few days later and never had trouble like that again

also my vx used to maybe 1 time very 2 months i would get to a stop sign or light and the vx would silently shut itself off, no sputtering or anything, just RPM drop and the dash would light up.. also when starting after sitting for under an hour.. vx would sputter a lot.. rpms would drop until stalling unless i held the gas for 10-15 seconds

fuel pressure regulator replacement took care of that stuff..

I've had mine up and die a half dozen times - almost all were as I was coming to a stop. Only once doing 75mph on an overpass.. SHIFT-N, turn key, keep going...

It was a ghost in the machine thing for a number of us. I've also read here that it could just be a hiccup in the programming and miscalculates fuel feed ratio causing to to run too lean and stall...:_shrug:

It happens a few times a year to me so I don't sweat it.

I'd vote for the fuel pump. Just a question: how much fuel did you have in tank when engine died? Because of fuel pump is cooled with the fuel if you get lower level (but enough for the continue running) the pump might overheat and stop working. Another problem in the tank might be the dirty first level in tank air filter which might be covered with paraffin. Also, some fuel pumps just normally wears at 150000 miles. You might want not to replace the whole pump assembly but just the pump itself which is significant cheaper (in Russia replacemnt pump cost about $100 while assembly is about $800).

Also when it happens try opening your gas cap. If it make a sound like a can of soda opening you may be experiencing vapor lock. It used to happen to me in the summer months. (I'm guessing that just the engine stops running but the electrical stays functional?)

I had some issues with mine due to a hot-water leak at a clamp and I had a coolant issue; also I undid my MAF once and had to reset the computer to get that to clear up.. You can check your codes at autozone.. dont need to go to a mechanic..just make sure you get the codes and he doesnt clear them out without tellin you what they were..

Peace
Jeff

Folks,

Greeting!!!!unfortunately, due to back problems, i was forced to park my pristine dragon. Last January, I purchased an Isuzu Trooper. Now, I am having this shutting off problem.
Question, where is the( fuel transfer switch), and how do I replace it???????

Any feed back will be greatly appreciated!!!!!!!!!!

THANKS!

I meant the ( Fuel pressure regulator), Where is it located, and how do I replace it?????

THANKS???

Top right back of engine above the intake manifold - it's round. Do a search as there's an entire thread detailed describing replacement with photos.

-- John

GUYS&GALS,

When replacing the FPR, is there still pressure in the fuel line, when the car is off???? If the the answer is yes, what do I do to remove the pressure??

THANKS!!

IIRC, the owners manual should have a page describing all of the fuses and their locations in the engine bay fuse box. Remove the fuel pump relay, then start the engine. Let it run until it stalls and you're good to go.

Even with no fuel pressure though, you'll want to have a few rags or paper towels to soak up the excess fuel so it doesn't get onto your engine, exhaust manifold, etc. when you take everything apart.

James,

I just replaced my fuel pressure regulator not to long ago using Dino's excellent write up:

http://www.vehicross.info/forums/sho...or+replacement

This should give you all the information that you need. There is a little fuel pressure, but if you cover the regulator with a rag when you crack it loose you should be fine.

The one thing that I will caution you about is to hold on to the allen wrench when you take the bolt off of the back of the metal cover. Mine dropped down the back of the engine never to be seen again. I heard it rattle around as it fell, but it made a soft "whump" when it stopped and I just couldn't find it so I had to cut another one down.

Good luck.

GUYS&GALS,

Firstly, thanks for all the information, it was extremely helpful. Secondly, after my buddy replaced the FPR, my baby is once again running like a champ.

THANK!!!!

If you still are having problems... you may want to check this out. I was having similar probs and after going through allot headaches and work found out that my only problem was that I wasn't closing the gas cap hard enough to create the vacuum needed. Tooooo simple!!!!! It needs those three clicks on the turning... at least.

My VX did this a few times.. the negative terminal on the battery needed to be cleaned, also the connector was kind of corroded. the connection was enough to get things started and moving, but if I hit a bump the right way everything died.

I have a copy of Dino's how2 in pdf format if anyone needs it (still haven't figured out how to post pdf's). PM or email me if you want it.