Limp Mode 02' GU3

[Rosco99]

Hi Guys,

I've had my new patrol for about a week now and I've noticed twice now that when driving for an extended period of time at 100km/h the engine will go into limp mode. I understand this is to protect the car from overboosting and as soon as I take my foot off the accelerator and reapply it stops. The car doesn't go into limp mode @ 110/120 or any other speed and doesn't seem to have any other effect than total loss of power until I reapply accelerator. Car is stock except for NADS. No boost gauge or egt sensor yet, I think when I take it for a service on Monday I'll see what that will cost.

Basically my questions are: seeing as this is a safety mode is it actually a sign that something bad is happening to my engine? Or does it simply mean its running as intended?

[paulyg]

What NADS have you got fitted? boost and egt gages would have been the first part of NADS I would have fitted, how did you set the boost pressure with out a boost gauge?
Try cleaning your maf sensor and see if that helps.

[Rosco99]

The NADS that I referred to was on the car when I bought it and has been for the last 150kkms. It was put in by SouthCoast 4wd. I assume they would have put everything in properly, perhaps the original owner decided to take the gauges with them instead of leaving them in the car for sale? Either way there is a catch can and and a dawes valve, I havent checked if the EGR is blanked yet or not but I assume it is.

[threedogs]

One of two things how have they blocked the hose to run the boost gauge.
you really need to re fit a EGT and a boost gauge asap to monitor whats going on.
Once set you should be ok, oh and disconnect the battery to re set the ECU so it will learn new values.
Is your IC oily or has it been replaced with a tigged number

Re fit gauges and get it Dynoed if funds allow

[Rosco99]

One of two things how have they blocked the hose to run the boost gauge.
you really need to re fit a EGT and a boost gauge asap to monitor whats going on.
Once set you should be ok, oh and disconnect the battery to re set the ECU so it will learn new values.
Is your IC oily or has it been replaced with a tigged number

Re fit gauges and get it Dynoed if funds allow

Gauges hopefully going in next week.
IC is very clean, might have been cleaned up a bit before I bought it though. Pretty sure its the stock one.
Not sure whats going on where the old boost gauge would have been

[Rosco99]

Hi guys,

Is not having a needle valve a problem? I dont see why I would need to control the spool up rate if I am happy with how it currently runs?

had a closer look at my engine this week and it would be really easy to chuck a boost gauge in, the area where a T-connector used to be has been replaced with just a straight connector. There is however no sign of either a damper on the vacuum line or a needle valve. And I don't believe there has ever been an EGT sensor connected, so I guess I'll have to pay someone to put one in for me.

Fairly sure the limp mode was caused by overboosting so winding back my dawes a touch once i chuck in a boost gauge should fix it. Gonna give the MAF a clean anyway because it cant hurt.

[mudski]

A needle valve will let you fine control the boost. And more often then not, its the fine control thats needed to overcome the limp mode, without sacrificing too much max boost. Plus your car will go much better with the needle valve.
But if your intent of just running a dawes the you will need to lower your boost pressure on the dawes.

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[Rosco99]

Just in case anyone was wondering what the cause was:

Took off the maf and gave it a clean, also shook about 1inch of red dust out of the air filter so I replaced it. Havent had it happen again.

[mudski]

I used to keep a spare maf in the glove box. Also a belt tensioner under the pax seat.

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