Very Rough Idle, Solid Brake Pedal and Stalling

[Guest]

Hi everyone,

Strange situation here... 

Yesterday I went to pull away up a hill in Coventry, UK and the usual power just wasn't there.
Felt like it was really struggling in any gear. At this point I got it into a large car-park where it lost all power-steering, brake pedal was solid and it wouldn't turn over and the throttle pedal felt slack and spongy.
It had been fine up until this point, no apparent issues earlier in the day or prior to the hill.

After leaving it a while, it turns over but only if I give it a fair bit of throttle. Upon releasing the throttle it will try to idle, stumble and splutter for a while then stall.

The car is a 2000 W-Reg MK1 1.8 zetec to give a bit more insight.
Work carried out on the car since I've owned it;

VSS replaced with official ford one (used to randomly cut out)
IACV replaced with official ford one (to fix previous rough idle/stalling problem)
Crankcase breather replaced with an aftermarket silicon one (original had collapsed causing rough idle/stalling)
Fully serviced over the summer with oil and filter change, air filter, fuel filter, pollen filter, new spark plugs all changed too
On 29th August 2016 - Full timing belt change with waterpump and tensioners

I'm hoping somebody has seen a similar problem before or knows where I could start looking?
I'm not sure if the rough idle and solid brake pedal are related or 2 separate problems that happened to materialise at the same time?

Edit;

1) Prior to towing it home, the car was scanned for any error codes but none were flagged up.

Any help will be greatly appreciated.

Many thanks,

David

Edited September 27, 2016 by Guest
Update regarding error codes

[dezwez]

get a code reader to see if there are any codes on it 

[Guest]

Hi there,

I probably should've put that in my initial post;

I got it towed home (thank god I added recovery to my insurance). The mechanic scanned for codes but non flagged up at all.

[TomsFocus]

When it stalled you will lose power steering and brake assistance, so those aren't actually problems. 

So we need to work out the rough idle and stalling.  Problem is there are many things that could cause that, and without any codes it may not be easy to find.  I would check for loose or split vacuum hoses, MAP or MAF sensor (not sure which this engine uses), coil pack/leads/plugs as a start...

 

[Guest]

The strange bit is that the power steering and brakes went before the engine cut out.

When I turn it over (with throttle otherwise it won't turn at all), the power steering comes back but the brake pedal is still stuck solid.

 

I believe it's a MAF on my model, until I can get it running smoothly I won't be able to check if this is a culprit. I've got a new official coil pack from Ford due to be delivered. I might splash out for some magnecor leads as I've heard good things about them.

The spark plugs are motorcraft ones supplied in a ford service pack and were replaced over the summer (possibly 1.5k miles on them now.) I'll check them for scorching/cracks when I get home this evening.

I'll have to wait until the weekend to check for vacuum leaks but will get back to you on that

[Tdci-Peter]

10 minutes ago, Oneilld3 said:

When I turn it over (with throttle otherwise it won't turn at all), the power steering comes back but the brake pedal is still stuck solid.

I wonder if the brake servo has gone, and is leaking badly.

This would stop the braking assistance (hard pedal), and would leak air into the inlet manifold. This would badly upset the idle, and cause rough running & stalling.

Not sure about the failure to crank on the starter motor without some throttle, I can not think of anything that would cause that. Marginal battery perhaps?

(This car seems to have the older cable operated throttle with separate idle valve, if that gives any clues)

To test for servo, try to disconnect the vacuum pipe to the servo, and plug the manifold fitting.

 

[mjt]

I agree with Peter. The symptoms you describe sound like a leak in the vacuum pipe from the manifold to the brake servo. I think your description of 'not turning over without some throttle' may be causing some confusion. I assume you mean it won't start unless you give it some throttle and then when you take your foot off it won't idle and stalls. Is that right? If so I'd say this confirms an air leak into the manifold from the vacuum pipe as Peter suggested.

[Guest]

1 hour ago, mjt said:

I assume you mean it won't start unless you give it some throttle and then when you take your foot off it won't idle and stalls. Is that right? If so I'd say this confirms an air leak into the manifold from the vacuum pipe as Peter suggested.

Sorry for the confusion there!!

Yeah, that is the problem; without throttle it will manage to ignite but die instantly. With throttle, it is hard to maintain a fixed rpm, revs will rise and fall under throttle (I was able to get it from my street to to my garage about 40 meters away).

Once throttle is released, revs will drop to between 100-500, bounce and judder for a about 5 seconds and then die.

Thank you for your help so far, very much appreciated!

Now it's in the garage, I'll be able to have a good look around and hopefully it will be a leaking vacuum pipe. Won't be until the weekend but I'll keep you updated

[TomsFocus]

Ah yes, I misunderstood first time around as well!  I would also agree with the brake vacuum leak as above.

But I'm still baffled as to how you can lose both power steering and brake assistance before it cut, the two aren't connected at all.  The PAS is belt driven from the engine, so unless the belt snaps, that'll always be working while the engines running.

[mjt]

I agree, that doesn't seem possible. The only explanation for that would be that David declutched after the engine cut out.

[Guest]

Hi all, thanks for the help.

After investigating over the weekend, I found a small split in the vacuum pipe to the brake servo just below the PCV vacuum hose. Ironically the PCV hose had also become detached from the pipe connection found just under the thermostat, so the system was letting in unregulated air from 2 locations!

It's now all repaired and running fine again.

As for the PAS, I'm not sure what was going on with it. This weekend I'm going to replace the aux belt as a precaution as I'm not sure when it was last done.