RS_Gav

Hi guys. Im hoping this is an easy one. Good mate of mine is experiencing a engine cut out at about 3500 in any gear. Car is a 94 Escos and is standard apart from a sports filter and big bore exhaust. I have driven it and it feels like a "limiter" type of cut. When it happens it naturally makes you jump off the gas. As soon as you get back on it it is fine....

Cheers,
Gav

MarkN

Sounds unlikely at 3500RPM but are you sure he's not hitting nthe boost limiter? Hitting it is exactly like you describe

S1rst

Are you sure its definatly standard?

RS_Gav

Cheers guys. It is a stocker alright. Im sure its a boost thing too but not too sure where to start. Amal valve? Maybe the actuator arm has been dicked with? Heres the kicker... the boost gauge in the dash is broken! Might need to put a aftermarket one on to see whats goin on.

Arnie

limp home mode?

Arnie

if the ecu detects a fault, it will set the rev limit at around 4k

ryan_belfast

Thinking the same thing!!! Car is boosting too much and the engine is cutting out...

MarkN

Are you sure a vacuum hose hasn't come off. This would stop the gauge working and also mean that the actuator diaphragm may not be receiving "full boost". That way it would never open and the engine would overboost straight away.

I've never known one of those gauges break. I bet you've got a hose come off somewhere...

ryan_belfast

Thats a pretty good call!

mcossie

If you don't have ECU default code,
It seems to be a fuel pump problem...

RS_Gav

Cheers guys!! All great points to check out.

Mark. If a vacuum line has come off would that affect the actuator pressure? That line comes straight from the turbo compressor yer? It just means that actuator would see max boost but the intake manifold would not?

If I put another gauge on, what is the standard pressure it should be running. And in turn, at what pressure will the overboost cut out come in?

Thanks for all your help guys... plenty to go on!

Arnie

If any of the vacuum line connected to the inlet manifold has come off, you should get unstable idle, no?

RS_Gav

Thats the other thing i was thinkin'. It idles very smooth with no noticable "lump"

MarkN

I think it's unlikely that it's a fuel pump issue (may well be wrong). If the fuel pressure started dropping off badly you'd get an effect more like a very bad misfire rather than a "cut-off".

It may be rather than a hose coming off that they are connected up incorrectly. The MAP sensor must be seing the boost otherwise it would underfuel and you wouldn't hit the limiter as it wouldn't have a clue what's going on.

It may be that if someone has been pulling at the hoses they have pulled the hose off the back of the boost gauge by mistake, or that they have left it off somehow...

It would probably be a good idea to have a look where all of the vacuum pipes run and upload a photo if possible. You could also try adjust ing the actuator a turn or so to drop the boost a touch.

Have you recently changed the exhaust BTW? Just a thought...

Also - have you checked the spark plug gaps at all? Cossie's a really fussy about the gap and if it's too big the spark will blow out and you'll get a really nasty jolt every now and then when the engine comes on boost... Just another thing to check really

Arnie

When my pump went, it felt like hitting a limiter.

Mike Rainbird

iTrader: (3)

It will be the crank position sensor (this is the sensor on the bottom pulley). Especially if the rev counter jumps about as it cuts out as it comes on boost.

You can try cleaning the multi-plug that connects it to the loom, as this normally gets water in it preventing the ECU from getting a proper signal. However, it normally means replacing the sensor, which is around £25 + delivery from most places (bar Ford ).