Legnum "failing to proceed"... (cuts out when selecting a gear)

[jdyort]

Hi all,

Well my good old reliable Larry Legnum is a little ill this morning. Had just done kid drop off No1, about to leave for kid drop off No2 and as soon as I put in in "D" (Automatic) it cuts out. The car will idle, does not matter if "Reverse" or "Drive" it will try to move and then stutters and stops. Will restart straight away and you can rev it in Neutral without a problem/.

If I give it a bit more pedal it will move a bit but then cuts out. I am thinking Auto transmission however, the transmission has felt good, no noises, shifts well. Car is completely stock and is not driven hard at all. It has not been dropping any fluid. I had a new IFS switch here so put that in just in case and I have stuck the paper clip in and it is not throwing any codes. Also looked at pipes etc and cant see anything unusual.

Any ideas greatly appreciated.

Thanks

Troy

 

[jdyort]

Ok, a bit more investigation. The car will crawl backwards or forwards below 1000 rpm. If you give it more than that it cuts out. Yet it will rev as per normal in park and neutral. If you stamp on the accelerator it will lunge and then cut out.

 

[Size1]

I wouldn't conclude transmission yet, do you blow black smoke. Had any work done recently?

 

[jdyort]

Yeah the fact that it rolls back and forward beneath 1000 rpm has steered me away from it being transmission for now (thank goodness). No work done recently, no black smoke. Thinking a sensor, the fact that it revs in Neutral and Park no worries is the bit that really has me stumped. What sensor could be different based on what gear you are in to force it to stall?

 

[pretzil]

If you determine its not the gearbox let me know, the car I am scrapping was able to idle around the carpark at under 1000rpm in forward or reverse but would clunk a bit if you tried anything else.

We assumed it was the box. No wave spring found in trans oil but it was black as tar.

 

[Size1]

What does your trans fluid look smell like?

 

[jdyort]

What does your trans fluid look smell like?

Strange to describe but certainly not burnt or anything I would consider ordinary. It is still a perfect translucent red. I reset the ECU again while out sniffing the oil. It is playing up now in Neutral and Park where it will rev but it is cutting out sometimes, it was not doing that earlier. (thanks for all suggestions and assistance too).

 

[Brianod]

I had a similar issue with my legnum. I tried unplugging the maf sensor and it drove fine. Plugged it back in the next day and worked again. Kept happening on and off for a bit until I got a second hand maf sensor hasn't happened since.

 

[jdyort]

I had a similar issue with my legnum. I tried unplugging the maf sensor and it drove fine. Plugged it back in the next day and worked again. Kept happening on and off for a bit until I got a second hand maf sensor hasn't happened since.

Thanks Brian, will try that this morning first up and see what happens.

 

[Brianod]

No worries you will get a few lights on the dash and will be a bit harsh changing gears but runs fine

 

[jdyort]

So I pulled the MAF sensor off and it was very clean, stuck it back on and without connecting it started the car, it ran rough but BOOM!!! I could drive the car. Reconnected it back up and the car was back all good. Pulled it apart and gave it all a clean with contact cleaner to be completely sure. I regret not checking it this morning before I started playing with it this morning to ensure it hadn't fixed itself over night so there is a little bit of doubt but will have to assume it was the MAF.

Beyond my understanding how the MAF could cause the behaviour in the car but a win is a win. Thanks Brian and Simon, for your help. Pretzil, I wonder if it was the issue with yours.
(experiences like this really appreciate how good a forum OZVR4 is).

 

[Brianod]

Happy days mate. It's random behavior for a maf sensor but if it happens again try disconnecting it and if it starts and drives fine then best to pick up a maf sensor. Mitz fix in vic always have them in Stock.

 

[VOLK]

I assumed it was afr related. Ecu couldn't account for the load of drive/reverse due to either bad vac leak or faulty sensor. Load increases, TPS value goes up, fuel tries to match, ecu unsure of air volume, afr causes stall. That was my guess anyway.

 

[naughtika]

almost similar to failing fuel pump,

you can start the engine and let it idle, but once you rev it it dies..

 

[jdyort]

So today it cut out again with my wife and kidlets in the car. Managed to get her over the phone to disconnect the MAF and crawl the short distance home. Pulled it apart tonight and I noticed oil residue in the t piece below.

This is the section that the MAF clamps onto. When I removed it I could see the oil sitting in the pipes.

So I know this goes down to the Turbos (T piece sits at point A)

Is it normal to have oil in that section?. To me I thought it was just an airtube but the way the pipe is ribbed had me then thinking it is designed to catch oil that runs up there from the Turbos.
I have ordered a 2nd hand MAF to get me by until I accept reality and cough up $600 for a new one and wait for it to be shipped from Japan.

 

[pretzil]

Yes, that is where the crank case breather vents oil vapor to. When people install catch cans they intercept the hose that goes to the 'penis' between the 2 legs going to each turbo intake.

You will always have oil there.

 

[jdyort]

Cool. Just checking (and paranoid).

 

[Brianod]

Mine would start no problem when cold I could drive 5 mins and run to the shop and when I came out it would start but die when I'd attempt to move. Are these symptoms simular?

 

[Kenneth]

Thread from the dead?

Not sure if there was a resolution, but I do recall one coming up on either this forum or Club VR4

 

[Tony_T]

Don't buy a new MAF! The cause of the fault is in the electronic part and is readily fixed with just a small soldering iron and some solder. The hardest part is getting the top cover off without breaking the four small plastic tabs that hold it on (I broke two of the tabs on mine and had to make up some clips from metal to keep the cover on after I repaired the fault). You could fix it in the car but it is easier if the unit is out on a bench. I had to delve really deeply into mine to find the cause of the problem: I traced out the entire circuit of what's on the PCB but now I know what the fault is the fix is very easy. Let me know if you're interested in a full description of how and what to do. If you don't fancy doing it yourself do you know anyone with a little familiarity with handling circuit boards and electronic components who could do the simple soldering job for you?