GU 2.8 Engine "Missing" problems.

[Rosscoe]

Hi, have had an issue with my 98' GU 2.8 over the past few months, every now and then it "misses" like a petrol engine does with fouled plugs, "stutters" a few times and then is right again, has done this 3 times in the last few months, initially thought it may have been fuel, put diesel additive to clean lines/injectors and all was good again only for it to play up again a short time later, I get my fuel from the same place all the time, is this leading to more serious costly problems. Air filter is new, oil changed every 5000. Car drives great 99% of the time, just a little worried atm........

Cheers.

[XTC]

Rosscoe, mine does the same thing, and is very random when it happens, but normally when you change a gear and start to accelerate again.

I've heard all sorts of things what can be causing it including, worn fuel pump, worn injectors, perished fuel hoses from tank sucking air past the hose clamps, some say its the type of hose clamp Nissan used, electrical gremlins, fuel filter leaking air etc, etc..

I'm starting to think mine may be a little more regular in wet weather or after washing the vehicle, and think it may be water getting into a sensor harness or plug, perhaps the crank position sensor.

Mines isn't bad enough to get worried about yet, but I don't think it is getting any better. And yes your description of the fault is perfect, if it was a petrol it would be a miss.

Good luck.

[YNOT]

If it only does the stutter on start up I would suspect a small amount of air getting into the fuel system.
The problem with intermittent faults is they are such a pain to diagnose because you can't replicate them on demand.

I remember a few years ago when I was working as a mechanic in a Ford dealer, I had a car come in for repair with the fault listed as "engine missing". I couldn't find anything wrong with it so my story simply read "engine located under bonnet after brief search"!

Tony

[Rosscoe]

Thanks XTC, yeah i am not overly worried just yet, but am being transfered to Queensland at the end of the year and dont want her to die on the trip will keep a close eye on it i guess and see what happens, and yes when changing up and accelerating, is not frequent but it is there.....

Thanks Tony, I hate the intermittant ones, always feel such an idiot when you take it to the Mechs and they say there is nothing wrong, that will be 200 bucks thanks.

[the ferret]

There is a chance the problem could be the "throttle position sensor" that would cause intermittent missfire when taking off. bit like a "flat spot". Cheers Rod.

[Bigrig]

There is a chance the problem could be the "throttle position sensor" that would cause intermittent missfire when taking off. bit like a "flat spot". Cheers Rod.

X2 - the TPS being faulty/loose connection/on the way out has a tendency to do just that ... Not sure how to test it (other than ECU diagnostics or being really handy with a multimeter I have been led to believe) ...

[Rosscoe]

Thanks guys will look at the TPS.

[trmays]

if it does it when you put it under load such as accelerating or driving up a hill it might be a slight slit in your intake pipe causing it not to have a perfect vaccum.

[RustyNails]

I had a similar issue and it was rectified by fuel injection guys by replacing a part at the back of the injection pump.
Not sure what the part is called but there are six spring loaded valves at the rear of the pump with the fuel lines running to the fuel rail. One of these valves had a sticky spring, replaced the valve and it ran perfect.

Sorry I can't be more specific.

[_Greg]

I have the same fault in my 98 2.8 GU. it was a worn injection pump. i had the pump rebuilt and after it worked fine. the symptoms are exactly the same as yours.