Rev Limit - Limp Mode

[mharvey]

Hi all,

Bit of a strange one. Remapped the car with an RSTuner a couple of months ago, all was well.

The other week I then had the car running on 3 briefly, went to pull over and it sorted itself out before I could. It's happened once since but again only briefly and there are no fault codes relating to the missfire.

Then the other night I ran into the rev limit (which is increased due to the map) car was warm and I only ran into it as I hit a slightly greasy patch of road.

As I did the car went into limp mode, I have tested since (ran into limit on purpose, never advisable but I wanted to check if the limp mode was related) and it has done the same thing again.

Any suggestions?

Thanks in advance

Matthew

 

[Kazumz]

I would say overboost but you don't have a turbo? Maybe the MAF targets too low for what the car is putting out now. I've got an issue with mine that if I hit 4,500 then I go in to limp mode and I need to key off and key on again. Its due to my MAF targets being too low and the car saying 'Oh s**t!' basically.

Take it back and have them raise them for you.

 

[mharvey]

Nope no turbo.
Not got anywhere to take it to adjust, was an rstuner generic map. Don't think that's the problem as it worked fine for months

 

[Dan@SJM]

I would say overboost but you don't have a turbo? Maybe the MAF targets too low for what the car is putting out now. I've got an issue with mine that if I hit 4,500 then I go in to limp mode and I need to key off and key on again. Its due to my MAF targets being too low and the car saying 'Oh s**t!' basically.

Take it back and have them raise them for you.

That won't be the cause. The MAF will not be anywhere near maxed out and cause limp mode. From what you've said it sounds like yours is seeing excessive boost pressure or even abnormal burn/knock detection and is shutting down to prevent damage. You want to look at live data and see what requested and actual boost is. If it's excessive boost the the boost pressure solenoid is at too high duty cycle for the boost. But that should've been checked whilst it was in for remap.

mharvey

Did it throw up any lights or codes after the limp mode issue?

 

[mharvey]

@mharvey

Did it throw up any lights or codes after the limp mode issue?

A light did come on, I was going rather quick though and consequently didn't have chance to take much notice. It went after I turned ignition on/off and there were then no fault codes.

From memory box with squiggly lines? Ignotion fault or similar maybe? Think it was bang in the middle. Not with car at the moment

 

[Jekyll]

I had that problem in my old 182 once and when I sold it the new owner (Azza_) had it. Turned out it was the crank sensor.

 

[MartinR]

Drive it harder!

 

[1958steveflying]

The light was the rev limiter light and will come on all the time you are hitting it.

 

[1958steveflying]

That won't be the cause. The MAF will not be anywhere near maxed out and cause limp mode. From what you've said it sounds like yours is seeing excessive boost pressure or even abnormal burn/knock detection and is shutting down to prevent damage. You want to look at live data and see what requested and actual boost is. If it's excessive boost the the boost pressure solenoid is at too high duty cycle for the boost. But that should've been checked whilst it was in for remap.

@mharvey

Did it throw up any lights or codes after the limp mode issue?

What is all this talk about boost pressure ?

 

[mharvey]

I had that problem in my old 182 once and when I sold it the new owner (Azza_) had it. Turned out it was the crank sensor.

Crank sensors not a bad shout I guess, easy to replace and not too expensive so may replace and eliminate that, fingers crossed

Drive it harder!

Haha I know, I need to try harder I guess

The light was the rev limiter light and will come on all the time you are hitting it.

Yeah....it isn't...thanks for the reply I guess :s

 

[Dan@SJM]

What is all this talk about boost pressure ?

He has a 1.2 turbo.

 

[1958steveflying]

He has a 1.2 turbo.

Then why did he reply with this !

[h=2]"Re: Rev Limit - Limp Mode[/h]

Nope no turbo."

In post 3 ?​

 

[Dan@SJM]

I was replying to the quote in my post. Then replied to the actual OP when I tagged his name. Not difficult to follow? Or do you want me to use multi quote next time?

 

[MartinR]

Then why did he reply with this !

[h=2]"Re: Rev Limit - Limp Mode[/h]

Nope no turbo."

In post 3 ?​

Whats a turbo?



mharvey

Have you sorted it yet

 

[1958steveflying]

I was replying to the quote in my post. Then replied to the actual OP when I tagged his name. Not difficult to follow? Or do you want me to use multi quote next time?

Okay my bad.... apologies, I had missed the point you we're not talking about the OP's car.. Note to self.... read and then re-read before typing... it's an age thing you know ! !

 

[Dan@SJM]

No worries. Apologies for the shirty reply.

 

[Kazumz]

That won't be the cause. The MAF will not be anywhere near maxed out and cause limp mode. From what you've said it sounds like yours is seeing excessive boost pressure or even abnormal burn/knock detection and is shutting down to prevent damage. You want to look at live data and see what requested and actual boost is. If it's excessive boost the the boost pressure solenoid is at too high duty cycle for the boost. But that should've been checked whilst it was in for remap.

@mharvey




Did it throw up any lights or codes after the limp mode issue?

Sorry for thread stealing mharvey but.

Dan, If I rag it in 1st and change at 6,000 then go straight in to 2nd the pull is phenomenal compared to starting off in plain old 2nd and then at 4,500 I hit limp mode. But If I start in 2nd and pull to 6,000 I have no issues with overboost? Going back down for a repair after Christmas anyway will get back to you if you'd like to hear?

 

[Dan@SJM]

It certainly sounds like a surge issue, IMO it's not MAF related (maf's very very very rarely cause limp mode if atall.) it might even be something like an engine torque monitor, torque exceeded code.

 

[Kazumz]

It certainly sounds like a surge issue, IMO it's not MAF related (maf's very very very rarely cause limp mode if atall.) it might even be something like an engine torque monitor, torque exceeded code.

So this is down to the fact that I'm running 145 Foot Pounds now and can this be fixed by the mappers?

 

[mharvey]

Whats a turbo?



mharvey

Have you sorted it yet

Nah mate, did it again today.
Went to Ad but Crank sensor was £££ that I don't really have at the moment. I guess it could be a couple things though so I'm going to try to find someone breaking a car, buy bits till I eliminate the problem lol.

 

[MartinR]

Matt PM cs_dave he is breaking his cup

 

[Dan@SJM]

So this is down to the fact that I'm running 145 Foot Pounds now and can this be fixed by the mappers?

Provided they know what they're doing yes. But without knowing the code it's hard to say what it is. I'm clutching at straws with my experience of other cars with the same symptoms

 

[Kazumz]

Provided they know what they're doing yes. But without knowing the code it's hard to say what it is. I'm clutching at straws with my experience of other cars with the same symptoms

I get an INJECTOR FAULT on the dash and it locks at 3,000 RPM until I key off. Could be Duty Cycle?

 

[MartinR]

I get an INJECTOR FAULT on the dash and it locks at 3,000 RPM until I key off. Could be Duty Cycle?

PM or start you're own thread flol

 

[Rubicon_]

Take the crank sensor out and clean it mate. Seemingly a common problem.

 

[Kazumz]

PM or start you're own thread flol

Oops!

 

[MartinR]

:rasp: