J4CK50N

This is also posted in General Technical.

Please could you help me?

I've just driven home in the past 10 mins and twice when i have put my foot down and it is accelerating hard to car just seems to cut out as if I have hit a brick wall. This happened in 3rd gear the first time and 4th the second time. I dared not try it again.

The car is a Type-R and is used every day, have had it 7 months and nothing like this has ever happened.

It doesnt happen on part boost etc just when the foot is planted to the floor. This is worrying me and I need to take it to work tomorrow.

Please help. Wot is the problem and how is it rectified?

Thanks

jameswrx

iTrader: (4)

sounds like fuel cut. Boost spiking over the boost limit causes the cut out.

With this heat though I'd hazard a guess your boost solenoid needs cleaning, I say this because you can hit fuel cut in colder weather (denser charge air, more boost), and as it's hot, it points to something else.

Either dirty solenoid, or have you had any mods done recently?, ie de-cat, air filter?

J4CK50N

Cheers James for the prompt response.

The car is de-catted but has been since I got it.

Standard air filter.

The car has been abit weird since this tank of petrol daft as this sounds. Wonder if Ive got a dodgy batch of petrol. I'm nearly run out so will put some more in tomorrow.

Just want it sorting.

On my way to the pub seemed fine. Pulling as it normally would with this thin warm air. Just thought i'd open her up a bit on the way home and this happened. P**sed my off a bit.

Hope the above helps mate.

greasemonkey

What fuel did you put in this time, and are you running OB? Don't forget with the hot weather (and thus higher intake temps), you need to be even more aware of det. Do you have a KnockLink?

It's always possible for a garage to accidentally fill their SUL tanks with regular unleaded, so that could explain a thing or two.

The other thing to be aware of, especially seeing as we know your car's nearly empty, is fuel starvation. The two times your car cut out, were you accelerating in a straight line, or round a corner?

jameswrx

iTrader: (4)

well if it's been that way for 7 months you can rule out boost spikes from new mods then.

I'd suggest that something may have happened to restrict the responce time of the boost control (ie dirty solenoid).

Have you got a boost gauge?.

It might be worth cleaning the boost solenoid out. Other than that I wouldn't know what to suggest apart from a 'specialist' looking at it.

Failing that, give it enough time and some genius will be along on here to help mate.

J4CK50N

Thanks you guys!

To answer the questions

I do not have a knock-link
I do not have a boost gauge
It is run on Optimax from the same garage every time
It does not have OB in but have purchased some to put in & i've been waiting for the tank to be empty as it says on the bottle.
I was going in a straightish line, certauinly no sharp bends etc.

One thing I forgot to say was that it cut out after a couple of seconds.

I am not particularly technically minded when it comes to cars, i know a bit but am no mechanic.

When it cut out the weather was cooler than when i was on my way there!

All you help is much appreciated and if your ever in the Yorkshire area i'm more than happy to buy a beer or two!

J4CK50N

Any other suggestions? Please?

BTTT

Boro

iTrader: (1)

Overboost in simple terms is where the boost pressure produced by the Turbo exceeds a predefined maximum. Once the limit is reached the ECU cuts all power to the engine for a fraction of a second. The result of this when accelerating hard in second gear feels like running into a brick wall

Or a more detailed explanation is:


The wastegate is held shut so that boost is generated and when the desired boost level is achieved the wastegate is then opened. However this is mechanical stuff controlled by electronic stuff - electronics can react quickly whereas mechanics can not.

What you find is that when the wastegate is opened the turbo is still accelerating, so for a moment the boost continues to rise until the turbo speed falls. This moment of higher-than-desired boost is overboost. Complex boost controllers try to "guess" when the desired boost level will be reached and then open the wastegate in time, so as not to overshoot it.
Causes of overboot include the T piece clogging up with oil. Also if the orifice (brass hole restrictor) is placed in the wrong line, it will also overboost. Depending on which model it is, it should either be in the line from the turbo to the T-piece or the pipe from the solenoid on the right side of the struct tower to the inlet manifold.

97 98 cars seem to suffer this the most. The hoses from the wastegate can be cleaned and the problem still comes back. Also dealers have removed the restrictor that is in the line to the wastegate and fitted a larger holed one, this lets the car boost to a lower level. Problem solved. Some dealers are drilling the hole slightly larger. Beware they do not drill the hole to large or your boost will suffer.

J4CK50N

bttt

J4CK50N

Cheers guys, i've got plenty to go at now on Saturday! Best stay off the cold ones Friday night or the car may never be the same after my meddling!!

Please could some1 now tell me how long they expect this to take me to clean the control solenoid, check boost hoses, clean T-pipe etc. If it helps I have access to ramps etc

Also if any1 has any pics or a link to help me that would be most appreciated!!

Also may as well check actuator etc as some1 suggested whilst I'm messing / cleaning. so again links pics etc would be appreciated!!

Thanks every1 for all their help!

J4CK50N

andypugh2000

Mine cut out the other morning reversing out my drive and took 20 seconds of cranking to restart, was told it could be the fuel pump relay, the contacts get dirty and it needs replacing, hasn't done it since though, worth a mention

ScoobyDuck

iTrader: (1)

yeah mines done that ! pain in the **** **** !

I'd clean the solenoid & check all the pipes and give it a go.
if not - you'll need to get the restrictor changed.

Steve

Paul_M

I had the fuel pump relay thing a while back, accelerating and the car would cut out for a few secs, it would jerk hard enough to lock the seatbelt mechanism! Sometimes would cut out and stay off for a few mins. At first I feared a bloody expensive repair but a bit of fiddling I worked out if I held the relay connector the car ran fine - removed it and gave everything a good clean and pressed the connectors together to make sure the connection is really tight - no probs since and that was almost a year ago

PS Don't confuse the original poster's problem with what I've replied above, yours is almost definitely fuel-cut due to overboost whereas the problem I had would occur even at part throttle.

PPS Does anyone suspect my engine could have detted in the above scenario due to fuel starvation? It doesn't seem to have caused any probs but I'm hoping there's no hidden damage that will manifest itself in years to come!