Cold start issue

MassiveJim

MassiveJim

MassiveJim

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22 Feb 2014
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Any ideas what this could be ?

I have a Mondeo ST220 on 148k
A "normal" startup on this car has no delay and engine starts as soon as the key is turned.
The problem I am having means I have to turn the engine over for 20 - 30 seconds then it sort of splutters and starts and runs fine.
This ONLY happens on a cold start and it doesn't happen every time.
I had it booked in to a garage to look at, following the phonecall I made booking it in, it got worse and was doing it every single time for a whole week, then it stopped doing it for a week, so I cancelled my garage appointment, yesterday it did it both in the morning before I set off to work and then in the afternoon when I was leaving work to drive home.

This morning it started fine again.

The car was converted to run on LPG about 90,000 miles ago, the LPG system was inspected and a fault found with a leaking "diaphragm" but that was replaced and the issue was still there.

When I turn the key I can hear the fuel pump priming itself, I have also tried letting the pump prime 3 times by turning ignition on/off before starting the car and it still did it.

has had plugs/leads recently. (in last 12 months)
 
Only ever happens cold.
Once the car has started I can immedietley turn it off and it would then start straight up.

Battery was changed recently.
LPG guy thought that there was perhaps a slow gas leak, and that when I went to start the car the inlet was full of gas and the car wouldn't start straight away because the mixture would be too rich and needed cranking until some of the fuel was cleared, so he changed the diaphragm which was split and would have been leaking but the problem still exists.

When the problem is happening it does seem to get worse the longer the car is left so his theory is sound, however I only tested it once by starting the car after being parked up for 3 hours. Normally the car is parked for 8 hours+
 
Gaygle said:
It does sound very much like a fuel pressure problem. The fuel in the line drops when it's left for a while then it takes quite a few turns to get the pressure back. My money would be on a weak fuel pump and/or leak in the fuel system (maybe injectors).
Click to expand...

Also on this, would I not expect other symptoms if the fuel pump was failing ?
ie poor performance or struggling at high revs etc ?

Performance is spot on once car is running, LPG gives slightly less overall BHP than Petrol and I can still feel the slight improvement in performance when the car is running on Petrol.
Which sort of indicates to me that the fuel pump is actually ok.
Im not well versed in fuel systems however so I could be completely misunderstanding how it works.

As for the leak, would a slight leak cause the smell of petrol ?
I haven't smelt any at any point.
 
So a little update on this, and some more thoughts from your good selves.
The problem still isn't fixed.

I took the car to a garage an hour away so that he could look at this, the reason being I believe it to be a gas issue and my local garage doesn't deal with gas.
He had the car for 2 weeks and it started up first time every time.
There was another issue with the car reporting running lean, a smoke test revealed a leak on a vac pipe that has been replaced now and on the exhaust (which is being looked at next week)


Since I have had the car back (picked up friday) it has had this cold start issue every day.
It doesn't even need leaving that long either, I drove 12 miles to KFC and we sat in so around 45 minutes ? and it had the issue when we came out.


I can hear the fuel pump prime up every time I turn the key in the ignition with no change in tone, I have just been out and turned the ignition on and off about 10 times in the hope to fully prime the fuel lines to rule out the pump and the FPR, and it still had the issue.
I think this safely rules out the FPR and pump anyway.
I did for a while believe it could be a leaking injector, but if that were the case I think it would fire up but run lump for a few seconds.


It could be coolant temp sensor but I think if that were faulty then it would give more problems would it not ? ie rough running at other times etc.
There has been an ever so slight fuel/oil smell in the cabin for a couple of seconds a couple of times when this has happened.
 
bainbridge said:
Have you checked for fault codes?
Click to expand...
yup the only fault code relates to engine running lean, which started happening after this issue.

Have replaced a vacuum pipe which the garage thought would sort that, he said if it doesn't he would replace the MAF next.
My normal garage is going to sort out an exhaust leak end of next week, and if that doesn't cure the lean running, we will look at cleaning/replacing the MAF.
I don't think the lean running is in relation to the cold start issue, simply because it started happening afterwards and it happens wether on petrol or Gas.
 
To be fair whilst googling my little fingers off Fuel pump has come up as a common theme on this car.

Its just that it runs perfectly in all other conditions which steers me away from it.

Could it be a fuel pressure regulator that is allowing fuel to leak back out of the loop in to the tank, therefore when starting the car i have to pump more fuel through the line before it will start ?
Not knowing enough about cars I don't know if my little test last night of priming the pump 10 times would negate the effects of that ?
Or even if I would get more issues if it was the FPR.

I'll ask my mechanic if he can do compression test and also check the coolant temp sensor whilst its in.
It is having a fair bit of work done though so not sure if he'll have time. (rear sub frame bushes, front brake caliper replacement on both sides, slight oil leak, blowing exhaust/manifold and a service)
 
Amp34 said:
Agreed with the others. It sounds like a fuel pump issue. I had something that sounds similar and couldn’t get to the bottom of it because it was so intermittent. After it failing to start completely and flooded the engine the mechanic worked out it was the fuel pump on its way out. Basically still pumping fuel but at too low a pressure to atomism properly causing minor/major flooding on a cold start. Replacement pump sorted it.
Click to expand...

Interesting, will certainly look to get a proper pressure test done in that case.
Could this still be the case even though at all other times the car drives completely fine, and still pulls hard right through the rev range in both 3rd and 4th ?

The LPG place did check fuel pressure but only through diagnostic comp, not with an inline tester. Said it was reading ok. (He definitely told me 3Bar on the phone, I just can't remember if he said "about 3 bar I can't quite remember or "3 bar") I know this pump should be running about 4.5Bar though
 
it seems to be getting worse or at least more consistent.
parked up for half an hour earlier and it did it when I came back to the car but didn't take as long to start.
It seems to be now that the longer the car is left the longer it needs to crank over before starting.
 
A little update on this.
PO443 is now cropping up, which relates to the CRV valve.
I guess it is getting stuck open and allowing fuel vapour to fill the inlet manifold whilst the car is stood, and also the car is pulling additional air down the vacuum lines.

BUT Ford no longer stock this part, on their system it says "in the case where the part needs replacing, please reuse old valve" It is/was part of a kit which includes the 2 pipes.
I have found a German seller on ebay selling them though so part has been ordered, but have to wait for it to arrive now.

Hopefully this cures it :)
 
MatteH Oxford said:
The evap valve stuck open would mean the car is actually running far too lean on a cold startup, that's the likely cause of your problem. Fuel vapour would be present, but a lot more air would be in that mix.
Click to expand...
you would think, but this problem only occurs when the car has been left for a period of time, so something has to slowly leak or get worse whilst the car is stood in order for me to have the problem.

If I crank the car for 30 seconds and then it starts, then immediately turn it back off again (so nothing has had chance to warm up etc) it will then start up straight away, just like normal.

I'll fit the new PCV when it arrives anyway and see if it makes a difference or not :)
 
PCV changed aaaaaaaand, no difference, still struggling to start :(

Exhaust leak fixed on front of engine (I think this is bank 1), still getting lean running on Bank 2, although there was an error code relating to the bank 1 sensor 1 O2 sensor.
 
fuel pressure gauge has now been connected to it.
its dropping fuel pressure pretty quickly. Its been sat outside for about an hour im gonna check it in a bit to see how much, but whilst talking to the mechanic for 10-15 minutes it dropped from 65 to 58ish.

connecting the gauge up dropped the pressure down to zero, turning on ignition brought that up to 40ish, then starting the car took it straight to 65
 
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