Sigma 150 cutting out - fuelling?

[Aitch42]

Hi there

We have been touring in North Yorkshire in our 2010 Sigma 150 and 11 miles from our hotel in Harrogate the engine started stuttering and cutting out. The problem seems to me to be with fuelling as it gets worse the more you depress the accelerator. We managed to nurse the car back to the hotel but hoped to head back down the A1 to home tomorrow. It feels like there is some dirt in the fuel system somewhere as if the car is left for a couple of minutes it starts again with a cough and a splutter. I had problems with the fuel filler hose (crap Caterham part which rotted after 18 months) which I wonder if some of the rubber has Allen in the tank.

 

Has anyone else had a similar problem? Any suggestions as to the problem?

 

Any ideas/thought would be welcome.

 

Howard

[Stationary M25 Traveller]

Is the one way valve in the tank breather hose the right way round ? Can you blow into the tank when you blow into the open end of the hose (just inside the chassis under the filler cap and slightly right).

 

Does the tank suck air in when you remove the filler cap when you have problems ?

 

Wouldn't think it was rubber bits from hose in tank.

 

Did it get wet the day before ?

 

Have you got AA or RAC cover if you get more problems ?

 

Edited by - Stationary M25 Traveller on 26 Aug 2012 18:14:44

[TobyCoulson]

I had similar problem with mine some while back and found out that a couple of the TBs had worked loose.

[Aitch42]

Thanks guys,

I will check the tank pressure thing in the morning - large glass of wine just ordered to get over the stressfull last hour!

 

The car has been running fine up to this afternoon so not sure what has changed but will do a thorough check of pipes etc before we attempt the journey home. Yes I do have the RAC service so we should be ok if it dies on the way, although when I had the problem with the fuel filler hose disintegrating they weren't much help and all they would do was duct tape the bits of the hose that were left nd send me on my way - lasted about 5 miles before is dissolved with the slashing petrol! Managed to nurse it home stopping to refill the tank every 20 miles or so - 180 quid to do 300 miles.....

 

Thanks again

Howard

[Stationary M25 Traveller]

Wow !!!! Lucky it didn't burst into flames !!

 

Quick fix with a bit of 8mm bore fuel hose and clips.

[slap_ed]

Hi

 

Have you been driving during any rain storms. If you have it might be water collecting in the plug holes and causing an intermittent short. The reason I say this is Caterham midlands did some work on my car and on completion they washed the car down. Whilst heading home the engine began to misfire and the more you pressed the accelerator the worse it got. I took it back, they dried it out and all was fine.

Worth checking

[CharlesElliott]

Water in the spark plugs definitely creates this sort of symptom. However, can you tell whether it is a electrical cut (very sudden, jerky) or fuel starvation (more gradual)?

[charlie_pank]

Fueling issues can also be caused by air leaks and TPS (check loom connections)

[Aitch42]

Thanks everyone for suggestions. We haven't been through any water as their weather has been surprisingly clement. It definitely feel like fuelling as it got worse the more I depressed the accelerator.

 

Going to fill up with fuel this morning, check all the connections, have some breakfast and then set out and hope we can get it home. I will book it in again I Caterham and get it checked out next week if we get back, if not we might have a stop over near Caterham midlands and get them to have a look tomorrow (if they are open).

 

Tanks again

Howard

[charlie_pank]

As suggested above if it's a blocked fuel tank breather (quite likely given your previous problem) then the car will be fine at first but if you drive until you have the problem, then stop and remove the filler cap, you'll get a big rush of air into the tank. If this happens then it's definitely an obstruction in the breather. If you cannot fix on the spot then try buying a temporary filler cap (halfords or a good petrol station) and make sure it doesn't make a perfect seal.

[Aitch42]

Managed to get as far as Bawtry and pulled off to get some fuel and just as we. And up the slip road the engine started to cut out! No hissing in fuel filler so probably not vacuum - now wondering if it's the lambda sensor as engine is hunting like mad on idle and cutting out. Going to wait a bit and see if it clears - otherwise it's the good old RAC!

Howard

[charlie_pank]

OK, it's deffo not a vacuum in the fuel tank then. Have a jiggle of the TPS connections and see if you can reproduce/fix the problem...most people who think they have lambda probe problems turn out to have TPS problems instead! If it's not measuring your throttle angle correctly, it'll be telling the ECU to deliver the wrong amount of fuel. Assuming that the default is half way, it'll give you too much fuel up to half throttle (and you won't notice) slightly above half throttle it'll feel great as it leans out then in the top 1/3 of the throttle it'll die through fuel starvation as the revs come up.

[Aitch42]

Update. Managed to get the car going again whilst on the phone to the RAC and it has run fine until we stopped for a rest break and now won't start again - getting really p*ssed with it. Hopefully once it's cooled down a bit it will start again and we can do the last 60 miles and I will get on to the techy chaps at Caterham tomorrow.

 

Tried unplugging the lambda sensor and no difference so probably not that.

Howard

[charlie_pank]

Does it make any difference if you unplug the TPS?

[Aitch42]

Final update.

 

Called the raC as the car was dead and was just waiting the 45 minutes when I remembers I had had problems just after I bought the car with the MAP sensor I think it's called - A small black box which sits next to the ECU which has a green plug in it. I unplugged this and the engine started fine and ran fine for the last 40 miles - hOpefly I won't have done any lasting damage. Thinking back this is the third one of these that I have had fail - the original on and then two within a few weeks of getting the car on the road.

 

Anyway he now with a nice cup of tea and only 6 and a half hours to do 180 miles - at last th ful consumption should be good!

 

Thanks for all your help/suggeStions - I will let you know what caterham say Tommorow

 

H

[Aitch42]

Update

Spoke to Caterham today and they confirmed that it was the MAP sensor which was at fault - they have had a bad batch of these but wouldn't move on reducing the 96 quid they charge. Found the same part at a third of the price so ordered 10 and will be putting the spares on here if anyone wants on.

 

Howard