Hi everyone.

I have recently put my mpi seicento back on the road, however I am having issues with it. The main aside from a fastish puncture is that under braking the car will stall.

This occurs when slowing down from highish speed. I use up all the stored vacuum, and then when I put the clutch in to change down or stop then the engine will stop

I can also get it to do it when stationary. If I hold down the brake pedal down hard the engine will eventually stall.

It is like the extra load the vacuum servo puts on the engine is enough to stall it
If I keep the revs up it's ok.

Any thoughts on what it could be?

Maybe something related to idle control? How does it work on an mpi cento? Only really have experience of spi centos.

Hope someone can help,

Many thanks

The servo shouldn't put any extra load on the engine -- after all, it's not operated by anything other than vacuum.

I'd expect it to stall when the fan came on, but.................

You might try removing the throttle body, give it a good clean outside, then inside, with aerosol carb cleaner (or in an ultrasonic cleaner).

Really? Would of thought it would of put some kind of load on the engine as it has to remove the air from the servo.

Anyway it is probably a idle control issue. Is it like the spi engine? As I was thinking maybe the stepper motor is sticking. But I do not know how it works on the mpi.

Finally what would a failed one way valve on the servo hose cause?

Thanks for your help so far.

i can confirm that lousy vacuum hose causes troubles when breaking!
my rev dropped when that adapter from which the servo body[the white round stuff back at the ecu] feeds was not properly put back.

maybe i'm wrong, but might worth a check

Hi,

Thanks for replies have taken car out and got it nice and warm. This has now caused it too cut out. It won't idle for very long at all. Anything over idle is fine. Have taken air filter off and it's pretty manky so first step is to give it a good clean out.

Here's hoping that will solve it. Will also check vac hoses.

Many thanks

Tom

trogdor said:

Will also check vac hoses.

Click to expand...

That was going to be my suggestion as a cracked vac pipe on the back of the throttle body was the cause of these woes for me. Admittedly this was on an SPI but I'd expect the symptoms to be the same if the cause is the same.

Hi Tom,

Sorry to resurrect an old thread but was wondering if you got to the bottom of this as my Sporting has developed the same problem.

Cheers Brett.

Have you followed the suggestions above?

Yup all good suggestions but culprit was the crank sensor. All sorted now.